Do OTC Head Louse Treatments Work? Part 2: Questionable treatments

Editor’s note: Thanks to Joe for Biofortified’s first post of 2012! Here’s to a great year of science blogging!
I like to think of myself as a skeptical blogger. I like to engage in critical thinking about scientific issues because this is an important aspect of my job as a graduate assistant. When I move into the workforce, I’ll still need some basic skills to parse evidence because this is my job as a scientist. Mythbusting is a great opportunity to do this, and I enjoy discussing things which may help people who read my posts whenever I can. Being an entomologist gives me some rather interesting opportunities to do this, which is leading me to discuss head lice of all things.

Pediculus humanus capitis by Gilles San Martin via Flickr.

In my last post, Do OTC Head Louse Treatments Work? Part 1: Mechanisms, I explained how the most commonly used FDA-approved treatments worked. In addition to those science-based products, there are many products that have no evidence of efficacy behind their claims, and that rely on fear to make a sale. What I’ve seen deeply concerns me not only as a scientist trying to make the world a better place, but as a parent trying to raise my daughter the best that I can. In this post, I’ve taken a few commonly sold products and listed some ways in which I think they play fast and loose with their claims.
A very brief review of how the nervous system works and how pesticides work in general can be found in the video below:

How do we know if treatments work?

Before getting down to the business of mythbusting, I think it’s appropriate to discuss how we know various products work. Treatments are assessed through clinical trails where infested volunteers subject themselves to putative treatments which are known as in vivo trials. In some cases, the lice are removed from the volunteers and exposed to the treatments in petri dishes which are known as in vitro treatments. In vitro treatments must be performed with the louse’s biology in mind because removing the louse from the host means that the louse is no longer in its natural environment. If the louse is not in it’s natural environment, the results gained from such a test may not be applicable to a real infestation. In vitro tests can disprove that a product works under ideal conditions, but proof of efficacy ultimately requires that the product be tested in real world conditions.
Clinical trials must have large numbers of people (and large numbers of lice) and untreated control groups. After all, insects are surprisingly fragile critters and even water or non-insecticidal shampoos may result in a small amount of mortality which is insignificant to treatment. Water or noninsecticidal shampoos can also temporarily clog the insect’s spiracles, resulting in immobile lice which could be interpreted as dead by a careless counter. Removal can physically injure the lice, which could cloud trial results if results are drawn from collected lice.
Another important aspect of clinical trials is blinding and randomization which make sure the person who is counting the lice isn’t aware of the treatment the person received. The human mind is a surprisingly bad tool for science because we tend to see patterns where none exist, and we may unintentionally superimpose patterns that don’t exist. Since everything in nature has some amount of variability (Anastasia is about six inches shorter than I am, Bug Girl is about a foot shorter than I am, and my boss is about a foot taller than I am for a quick example) we use statistics to tell us what the probability is that our results are due to random chance, eventually ending up with something known as a P-value. Followup observations are also required to show that the patient remained louse free, that is that there weren’t any hidden adults or unhatched eggs because the unhatched eggs can restart infestations.
Last week, I discussed some common OTC head louse treatments. While effective, there are some problems with resistance for some OTC treatments which results in failure of some treatments. This is a product of evolution where some lice are able to survive treatment because they have some random mutations which just so happen to be beneficial in a pesticide filled environment. The mechanisms of this resistance are actually similar to agricultural pests which have been treated with the same product.
One thing astute readers may have noticed is that I didn’t shy away from the use of the word ‘pesticide’ when discussing these treatments. One of my very first posts on Biofortified revolved around the definition of the word ‘pest’ which is completely anthropocentric. A pest is any critter which annoys us in the slightest, and a pesticide is a compound which kills a pest. Insecticides are used to kill insect pests and head louse treatments are referred to as ‘pediculicides’ because they kill lice. All pediculicides are insecticides (because they kill lice, which are insects), and many of the less toxic insecticides used in agriculture have been repurposed as pediculicides. Often times with head louse treatments, you hear companies claim with great pride that their products are pesticide free, are great at killing lice and that no resistance has evolved to their treatment.
Well… how do these claims stack up?

Uncomfortable Truths

Current packaging of products discussed in this article. Product images taken from the websites of their respective companies, used in accordance with the Fair Use Clause in US Copyright Law.

The use of agricultural insecticides to treat head lice is somewhat of an uncomfortable truth, and many companies have taken advantage of this to market head louse treatments. Despite what any label you read may say, any product which claims to kill lice is an insecticide by definition. It doesn’t matter if these are plant extracts, because pyrethrum falls straight into this category and it is classified as an insecticide. In fact, I would even go so far as to argue that a product is engaging in false advertising if it claims to kill headlice while being pesticide free. This, of course, doesn’t mean that all products must directly interfere with the inner workings of lice to be potential treatments.
Some compounds like mineral oil are used as insecticides in agriculture to kill aphids by suffocating them. The product marketed as ‘Lice MD‘ in the picture above claims to kill lice through a similar mechanism. The fact that these chemicals do not interfere with the neurological systems of insects does not mean that the product isn’t an insecticide. If the product claims to kill lice, as Lice MD does, it is claiming to be an insecticide.
A couple of examples of products that play fast and loose with advertising, in my opinion. Remember: natural products can be just as bad as synthetic products. Also, any product that claims to kill something is certainly not pesticide free. Both images taken from the websites of their respective companies, and used in accordance with the Fair Use Clause in US copyright law.

Uneasiness about insecticides has also given rise to many products which are derived from natural sources; these are popular because of a general assumption that natural products are safer than synthetic insecticides. The advantage of this from a company’s point of view is that these products don’t have to go through safety or efficacy testing, depending on how they’re marketed. The Dietary Supplement Health and Education Act of 1994 allows many products to go straight to market without testing under the guise of ‘supplements’ which allows them to make sometimes outlandish health-related claims. Homeopathic products are similarly exempt from safety and efficacy testing, which gives companies a great loophole to sell products which make medicinal claims.
This is a successful tactic because it plays on the unease parents have about treating their children with insecticides to kill lice. Unfortunately for these uneasy parents, the assumption that natural products are less harmful than synthetic products doesn’t always hold true. The LD50s for many synthetic pyrethroids are higher than their natural counterparts. Ricin and amantin are both incredibly powerful poisons derived from plants and fungi respectively. Eucalyptus oil, if used improperly as a head louse treatment, can have dire consequences including seizures and death. Many natural components can have chronic effects, too. Cyclopamine, derived from Vetratum californicum, causes some rather disturbing birth defects by inhibiting developmental pathways. Rotenone, a pesticide once used widely in organic agriculture, has been linked to Parkinson’s disease in workers exposed to sublethal doses of the toxin over the course of a very long time. Aflatoxins are powerful carcinogens produced by fungi which threaten food supplies all over the world. Even something as seemingly innocuous as a cockroach sex pheromone can be carcinogenic.
To be safe, it doesn’t matter if a chemical is derived from natural sources. Instead, safety depends on how the chemical interacts with the molecular machinery that keeps us alive. The safest way to make a new product is to construct it with chemicals where we know what everything does, as opposed to treating with soups of unknown composition. Unfortunately, this isn’t always possible because purifying and testing a compound for effects is extremely expensive and can take years of effort.
One of the components in the Quit Nits formula is a plant called Delphinium, a plant genus which is famed for its toxic alkaloids that poison cattle and make this plant genus a pest of cattle pastures. I’ll discuss this claim further in another paragraph, but the plant is in the formula at a concentration that is most likely too low to harm either lice or people. Other claims on this product are technically honest, but misleading. Some components of this product have been used in agriculture as insecticides. Lice consume a blood diet, and would probably have to eat these pesticides to see any effect. Components of the shampoo are toxic, but the concentrations these components are used in are harmless to people and are probably harmless to lice as well. As far as I can tell, most of these components haven’t been tested against lice in literature available to researchers. The statements made in the Quit Nits product comparison chart are misleading on multiple levels.

Misleading Statistics

Study methodology and results from the Lice Sheild website. This usage of the information from the company’s website is in accordance with the Fair Use Clause of US copyright law.

Many products give misleading statistics that aim to trick parents into believing the product works. For example, let’s take a look at a product called Lice Sheild. They give a description of an experiment on their website that seems like a good test on the surface but is missing any information that actually allows you to draw any conclusions. For instance, they give P-values in their experimental setup, but do not give any information needed to verify their results. The P-values given imply statistical significance, but without any information on repetitions, sample sizes, means, or deviations the information is basically useless. There’s no way to check their math to see if the statistics were correctly performed. There are also no details on how many lice they used for the experiment. If they used two repetitions of five lice (the minimum required for 80% repellency with four lice moving between hair strands and away from the treatment), this would be a negligible result. If they used ten repetitions of 500 lice, the results would be a bit stronger. There simply isn’t enough information here to determine if the statistics were correctly performed.
Also lacking is a description of the experimental arena which is important because there are many ways in which you can test repellency that would potentially interfere with louse movement. If they placed the louse in a container in a patch of hair, one wouldn’t expect lice to move away from the hair at an appreciable rate. Many products are tested by placing the lice on a piece of filter paper and looking at the percentage of lice which move away from the product. While a test like this may appear to show some repellent activity, it’s not actually a very good measure of how good your product repels lice in real world conditions. Using in vitro tests means you’re trapping the lice in a place with the repellent and giving them essentially unlimited time to make their choice. This is a big problem because they’re using a timeframe that’s irrelevant to head louse transmission. Lice are mainly transmitted through hair to hair contact, and it’s rare for two people to be in hair to hair contact for this amount of time.
In short, showing 80% repellency is very different than saying that you have a 80% reduction in your chances of getting head lice. The company which makes Lice Shield uses questionable statistics to claim their product repels 80% of lice under conditions that don’t reflect the conditions where lice are transmitted, then turns around and claims in their FAQ this means that there is an 80% reduction in head louse transmission without any evidence for this claim. These two claims are quite different, because repellency doesn’t necessarily translate to a reduction of infestation.

Homeopathic Medicines are Marketed Differently than FDA Approved Drugs

Homeopathy is a system of beliefs which claim that serially diluting a ‘medicinal’ substance makes it stronger. These dilutions are pretty specific, for example the letter X denotes a 1:10 dilution. If a product is diluted 6X, it’s diluted to 10^-6 which is about one millionth of the original concentration. The idea that diluting a potential louse treatment makes it stronger is ridiculous because if the chemicals in any treatment interfere with insect biochemisty, they must be within a certain range to have an effect. Too much, the person gets poisoned (but the lice still die). Too little, and the lice survive and resistance can build up after the more susceptible individuals are culled from the population.
Homeopathy defies essentially every principle in science from biology to physics. Homeopaths claim that water has memory but, to paraphrase Tim Minchin, this ‘memory’ of water seems infinite when paired with some substances but water seems to have a case for amnesia when it comes to more harmful substances. Homeopathy has no a plausible mode of action.
The next paragraph of my post may get me into hot water with some of my skeptic friends. Many skeptical bloggers have taken on homeopathy. Let me restate: homeopathy has no plausible mode of action. I want to put this in writing to avoid the inevitable criticism from other skeptical bloggers. I also want to avoid the quote-mining from naturopaths who may want to say that I support homeopathy. I am not claiming the efficacy of homeopathy because there is no evidence that it works, and there is no plausible mechanism by which this practice could possibly work.
I am considering some homeopathic products as potentially effective. Why? Homeopathic formulas are exempt from safety and efficacy testing by the FDA which gives many products a free pass when it comes to clinical trials. Many products aren’t actually homeopathic because they contain ingredients in concentrations that could potentially have an effect. These products are often classified as homeopathic so they can make medicinal claims. A cold remedy product marketed under the name Zicam is a good example of this. Zicam was a solution of zinc which was marketed to treat the common cold after it was shown that zinc ions could interfere with viral replication in in vitro tests. The product was eventually recalled by the FDA because it was found to destroy the sense of smell. Another example of a product sold as a homeopathic remedy with potentially active components is sold under the name of Quit Nits.

Unlikely Modes of Introduction

Quit Nits bills itself as a homeopathic remedy and contains a bunch of plant extracts from several different species. As a result of intense selection by insect herbivory, all plants have some sort of anti-herbivore defense. Many plants have toxic components as a result of being under selective pressure to develop such components over the course of millions of years. Plants represent a wonderful treasure trove of different types of novel pesticide chemistries. After all, this is how we got pyrethrum. Despite the fact plant extracts are potentially plausible pesticides in and of themselves, we shouldn’t assume that any plant can kill any insect.
The first thing that raises a red flag for me in the Quit Nits formula is the mode of introduction of this pesticide. Some pesticides (see this RNAi post, for example) must be eaten to be toxic, and these are referred to as stomach poisons. Others can be absorbed, and are referred to as contact poisons. While this product does have toxic components, the fact these plants have natural toxins doesn’t automatically mean that they’ll be absorbed by the lice. Because the lice feed by inserting their mouthparts into the host, it seems very unlikely to me that they’d actually be able to pick up any pesticide by eating it unless the pesticide was in the blood of the host in appreciable amounts. Thus, any active ingredient would have to be absorbed through the exoskeleton.
A second thing that I am concerned about is the formulation. Spraying plant extracts on crops and lathering the same stuff into hair and then washing it off are very different modes of introduction. Pesticidal activity may not be preserved by the shampoo, even if the substance is downright toxic to bugs when dissolved in water. This stuff needs to be tested on lice in the formulation offered for sale before it can be said to have insecticidal activity. The mode of introduction and dosage play vital roles in the insecticidal activity. It’s possible the active ingredients wouldn’t retain their insecticidal activity in shampoo or that they wouldn’t be in contact with the lice long enough to be toxic. No pesticide kills every insect with equal efficacy in every situation. This is why the ultimate test of any pesticide is to test it on the pest in the situation you’re going to use it in, in the formulation in which it will be used.
Third, the mode of action of the two active ingredients means that they are unlikely to affect lice. Extract of the plant Delphinium and extract of a plant called Sabadilla (Schoenocaulon sp.) are listed as active ingredients at one part per million. There appears to be little work evaluating Delphinium for insecticidal activity, but Sabadilla and Delphinium both contain veratridine which acts as a stomach poison in insects. Because lice feed by inserting their mouthparts into the skin of the host and sucking blood from capillaries under the skin, I have a tough time believing they’d actually pick the insecticide up in appreciable amounts unless the toxins were absorbed directly into the bloodstream. Since the active ingredient is toxic to humans, there would probably be some major issues with the product if it made it’s way into the bloodstream. The mode of action here renders me skeptical that the lice would pick up a toxic dose of the pesticide in the first place.

Pesticides Used in Doses Unlikely to be Effective

The biggest problem with Quit Nits is the concentrations of the active ingredients. It’s the dose that makes the poison and if you look at the label of the product in question, there are two ingredients that are listed as parts per million and one component that’s in there at a 1:100 dilution.
Purified components of Sabadilla have been used as pesticides for high value orchards like oranges and mangoes. The lowest concentration for semi-purified Sabadilla alkaloids is about .1 g/l, or about one part in 10,000 if we’re going by weight. The extract of the plant seeds, of which the alkaloids are only a small part, is about a hundred times lower than this in the quit nits shampoo. The seeds of Schoenocaulon contain 2-4% insecticidal alkaloids by weight, which means the alkaloids from Sabadilla are present at one part in 25,000,000 in the shampoo.
Delphinium contains veratridine in appreciable amounts as well and has a large amount of other toxic alkaloids in addition to veratridine. It’s difficult to know what concentrations the insecticidal alkaloids are present in Delphinium because there are simply many potentially insecticidal alkaloids in these plants. However, we can make some educated guesses because researchers have purified alkaloids from Delphinium. The individual components are present in milligram amounts with all the alkaloids being present at about 6 grams per kilogram of plant tissue. If we assume the insecticidal alkaloids are present at a concentration of five grams per kilogram of plant material to make our math easy, this means that the insecticidal components comprise about one part in two hundred per unit weight. The concentration of plant in the shampoo is about two parts per million, which means the alkaloids are present at one two hundredth (1/200) this concentration. Given generous assumptions of grams per kilogram amounts, the active ingredients would be present part per hundred million concentrations if we assumed all of the alkaloids in the plants had insecticidal activity.
These plants combined are in about one part in 500,000 in the shampoo. This means that the concentrations of the insecticidal alkaloids is about one part in 4-6*10^-8 parts depending on the alkaloid concentrations of the plants used. Because the lowest concentration of this pesticide used in agriculture is one part in ten thousand, this comes out to a ballpark figure of somewhere around 1,000 times lower than the lowest dose used in agriculture. The dose the lice will be exposed to in the shampoo won’t be great, as there will only be a couple grams of the shampoo used on the entire scalp. To give you an idea of what the pesticidal concentrations are in other louse products, pyrethrum is generally in antilouse shampoos at one part per hundred (one percent). Malathion is generally present at one part in two hundred parts, or one-half percent. This means that the crude alkaloids from the plant extracts would be present at one one millionth the concentration of the active ingredients that have known insecticidal activity. The improbable mode of action combined with the low amounts of active ingredients in the plant means that I would assume these ingredients are essentially inert without proof that they kill lice at these concentrations.
These ingredients aren’t the main stuff in the Quit Nits treatment, though. The plant extracts listed above are in parts per million, but Quassia amara extract is present at a 1:100 dilution…about 10,000 times higher than Sabadilla and Delphinium. Furthermore, it’s in the ballpark of the Pyrethrum extract. So what about Quassia?

Ingredients with No Proof of Efficacy

Quassia amara is an interesting plant because it contains one of the most bitter substances in the world. These substances are called quassinoids, and have been examined for insecticidal and antifeedant activities against a wide range of pests. In many cases extracts and purified components from Quassia have been shown to have insecticidal and antifeedant activity, but it wasn’t always clear to me whether the antifeedant activity was so strong that it led to mortality. In other words, it was difficult to tell if the substance made the food taste so bad to the bug that they’d rather starve than eat. Either way, we’re interested in it’s activity against lice in particular.
There have only been two papers which have examined Quassia extracts against lice. One appears in a Dutch journal in 1978 and another in a Spanish journal in 1991. Since these papers are in rather obscure low impact journals, I was not able to access them directly through my library and instead had to rely on their descriptions in review articles. The review articles weren’t exactly favorable towards Quassia as a louse treatment. The Dutch paper claimed high efficacy, but the experiment was apparently ran as an un-controlled, un-randomized, un-blinded experiment and counts as nothing as far as proof goes. The Spanish paper claimed high efficacy, but the review states that the Spanish paper concluded that Quassia would only have repellent effects but didn’t mention whether the extract had a clinically relevant success rate. There have been no well performed tests of Quassia as a head louse treatment, and the few tests that have been performed have yielded conflicting results. There’s simply no proof that the “active” ingredients in Quit Nits work.
Quit Nits also sells a repellent spray that has undergone independent testing. One paper compared it’s repellent activity using a filter paper repellency test, incubating the lice with filter paper treated with repellent on one side and water on the other. The objective was to measure what percentage of the lice moved away from the treatment. At the earliest time point measured (two hours), Quit Nits performed about as well as water. At later time points, there was some non-significant repellent activity. Another paper looked at the repellency of Quit Nits under real world (or close to real world) conditions and looked at whether lice would transfer to hair under approximated hair-hair contact conditions, if the lice would move on the hair treated with Quit Nits repellent spray, or if the lice would feed on the forearm of one of the authors who performed the study. For the hair tests, KY jelly was used to simulate greasy hair and Quit Nits fared no better than this. For the skin tests, bare skin not receiving any treatment was used and the lice exposed to Quit Nits treated skin fed just as well as those on bare skin. Quit Nits repellent spray simply doesn’t repel lice, as far as the current experiments show.

Some Products Have no Plausible Mode of Action

The first example of a product with no mode of action is a product called X-pel. In fairness, I’ve only seen this at a few small grocery stores in Iowa, but the fact something like this is sold at all really worries me. The product is a shampoo which consists of ground up honeybees, phenol, and an uncommon species of Rhododendron at femptogram concentrations (15X), or one part in one quadrillion. On their website, they give a couple of vague descriptions of various tests. The tests contain very little methodology and give no statistical information about their results. They claim a few ‘major universities’ were involved in the testing of the product, but neglect to give any sort of contact information or any publications generated as I described in the Quit Nits treatment. They have a video on their website, below, where they show an in-vitro test that consists of them drowning a louse in the shampoo. Because lice can be inactive for a long time following immersion in water, there is no evidence given that the lice in this video were actually killed. They also show an uncontrolled, un-randomized, un-blinded test of a single subject without any apparent followup as proof that their product works. Phenol here is the most likely ingredient for insecticidal activity, as the concentration of the Rhododendron is far too low to do anything at all. Quite frankly, I’m not sure how honeybees are supposed to kill head lice unless we assume the venom glands were somehow involved, but I find this unlikely. The ingredients used in this product are only used in vanishingly small concentrations, and there’s really no way to justify using ground up honeybees to treat head lice.

Another product marketed under the name Licefreee! is little more than a concentrated sodium chloride solution. While it’s plausible the product could suffocate the lice, the data for suffocants in head lice treatment isn’t exactly convincing. Because lice are coated in a waxy layer that prevents dehydration, I find the claim that a 10% salt solution will kill lice suspect. As far as I can tell, there’s no evidence of this product works either because I’ve only seen this mentioned in passing under ‘folk treatment’ sections of review articles. I’ve seen no primary literature articles dealing with concentrated salt solutions as lice-killers.


Many of these companies use a variety of tactics to sell their products that have nothing to do with efficacy. Many use highly questionable advertising methods, like capitalizing on patient fears of synthetic medicines and pretending to identify with their customers to sell them products of uncertain effectiveness. Some of these products even go as far as to claim to be pesticide free while still claiming to kill lice. Many of these products claim to have been invented by parents, but as a parent myself I cannot imagine marketing a questionable head louse treatment and this is a big part of why I’ve written this post.
The science-based products currently on the market that I mentioned in Part 1 have been thoroughly studied and activity proven with the obvious exception for strains of lice that are resistant to some treatments. Even though there is a risk to any product you’re bound to use, the risks of these products have been investigated and have been taken into consideration when formulating treatment regimens. I can certainly understand anxiety about exposing kids to pesticides, but when looking at alternative treatments one needs to ask whether they’re safe and effective. Extraordinary claims require extraordinary evidence. If a product you spend money on makes any sort of claim, you should consider the claim extraordinary and ask for evidence behind the claim.
ResearchBlogging.orgBurgess, I. (2009). Current treatments for pediculosis capitis Current Opinion in Infectious Diseases, 22 (2), 131-136 DOI: 10.1097/QCO.0b013e328322a019
Leone, P. (2007). Scabies and Pediculosis Pubis: An Update of Treatment Regimens and General Review Clinical Infectious Diseases, 44 (Supplement 3) DOI: 10.1086/511428
Canyon, D., & Speare, R. (2007). Do head lice spread in swimming pools? International Journal of Dermatology, 46 (11), 1211-1213 DOI: 10.1111/j.1365-4632.2007.03011.x
Heukelbach, J., Canyon, D., Olivera, F., Muller, R., & Speare, R. (2008). Efficacy of over-the-counter botanical pediculicides against the head louse based on a stringent standard for mortality assessment. Medical and Veterinary Entomology, 22 (3), 264-272 DOI: 10.1111/j.1365-2915.2008.00738.x
Lebwohl, M., Clark, L., & Levitt, J. (2007). Therapy for Head Lice Based on Life Cycle, Resistance, and Safety Considerations PEDIATRICS, 119 (5), 965-974 DOI: 10.1542/peds.2006-3087
Leone, P. (2007). Scabies and Pediculosis Pubis: An Update of Treatment Regimens and General Review Clinical Infectious Diseases, 44 (Supplement 3) DOI: 10.1086/511428
Greive KA, & Barnes TM (2011). In vitro comparison of four treatments which discourage infestation by head lice. Parasitology research PMID: 22030833
Canyon, D., & Speare, R. (2007). A comparison of botanical and synthetic substances commonly used to prevent head lice (Pediculus humanus var. capitis) infestation International Journal of Dermatology, 46 (4), 422-426 DOI: 10.1111/j.1365-4632.2007.03132.x
Rossini, C., Castillo, L., & González, A. (2007). Plant extracts and their components as potential control agents against human head lice Phytochemistry Reviews, 7 (1), 51-63 DOI: 10.1007/s11101-006-9026-0


  1. Excellent discussion of fact and folklore pertinent to mainstream and alternative anti-louse products. Purveyors of many of the products mentioned effectively skirt regulations and/or common sense. Indeed, many make claims that either are obvious misrepresentations or are phrased in a manner that causes readers to believe they’re based on more objective evidence than really exists. Sadly, FDA gives these (and most other alternative and ‘health’) products a disturbingly wide playing field to hawk their claims, wares and snake oils. The FTC is more inclined to take notice if the products fail to produce the desired outcome, and the CPSC might act if the user is harmed by the product.
    Readers interested in trying to further sort the wheat from the chaff might be interested in the educational resources on lice, bed bugs, ticks and other pests offered by IdentifyUS LLC ( and commentary at Before one considers reaching for any anti-louse product, it is critical to ensure that the target pest is really there and active. MOST applications of anti-louse products seem to be on children who are not infested with lice in the first place. That’s a much larger problem than whether or not an anti-louse product will be effective. Much more on that topic, as well as resources to help with pest identification, can be found on my website and blog.

  2. As a mom of 6 in a region where head lice is common, I have never treated my kids with any chemical lice treatment, natural or otherwise. Maybe I have that luxury because kids here can go to school with lice, but combing out the hair with a fine-toothed comb, every other day, for the length of a louse’s fertility cycle (about two weeks) does the trick. The lice are anyway resistant to the chemicals, which rarely kill eggs.

  3. Interesting follow-up to the first article. Appreciate the info! And Hannah in many areas of the U.S. now the no-nit policy in schools has been lifted based on recommendations from the American Association of Pediatricians and the National Association of School Nurses. I agree that there is a shocking gap in regulation of “alternative” products, and also that in the end common sense is the best tool to use when dealing with lice, or anything else.

  4. I am saddened by your lack of knowledge of the product. Yes, Licefreee is very effective, and has been proven as such, as well as undergoing more studies at the moment. It is regulated by the FDA, and Licefreee has been reviewed many times since its launch in 1999.
    I can see that you have obviously never dealt with head lice. For if you had, you would know how frustrating the traditional chemicals are to use. We receive a lot of calls and emails daily from frustrated parents who have finally found a solution with our products. And why would you put chemicals on your child’s head when you don’t need to?
    Also, to correct your assumption, Licefreee does not suffocate the lice, it desiccates them. I suggest you conduct your own study with live head lice and you will see that it actually does work instead of drawing conclusions based on limited information.

  5. Perhaps Dana could enlighten us on where the data is that demonstrates the effectiveness of their product? If the product was launched in 1999, doing a study right now is rather late.
    Your products say they are homeopathic, which sounds like they have been diluted beyond usefulness. How is that supposed to dessicate the lice?
    It is hard to draw good conclusions when your company website has limited information on it!

  6. First up I think we may be a little quick to jump on the homeopathy is bunk (it is, but I posit that to call this product homeopathic is a nonsense) bandwagon right now – a 1X homeopathic sodium chloride solution (one of the products) is 10% sodium chloride (approximately 2M), 2X is 1% (approximately 0.2M)
    So the question is –
    Would 2M NaCl (assuming 1:1 mix is 1000g in 1000ml, 1:10 = 100g which is roughly 2M) solution kill nits with 100% efficacy? Seems an easy enough question to answer – would a 2M solution of sodium chloride be sufficient to dessicate an insect? If yes the product could work, if no then it couldn’t.
    I do find it funny that Sodium Chloride apparently is no longer considered a chemical though, unless “why would you put chemicals on your child’s head when you don’t need to” was stated ironically (nevermind benzyl alcohol, cocamidopropyl betaine, caprylic / capric triglycerides, coconut oil, disodium EDTA, fragrances, purified water, sodium laureth sulfate, tea tree oil – none of which are apparently chemical in nature)
    So now all that is required is either a link to peer reviewed evidence that 10% salt kills lice, or the word of some kind of insect related scientist… who knows, maybe some of them read this kind of thing (I heard a rumour one may have written it, but I find that highly unlikely!)

  7. I’d also guess that the product is called homeopathic so that
    a) It doesn’t have to go through rigorous testing.
    b) Marketing ploy – in the minds of the deluded homeopathy is a good thing, make the connection without actually doing anything homeopathic (although I assume the correct shaking is done, just for the sake of staying vaguely honest!) and it is possible to have a “homeopathic” solution which does things (If you don’t believe me take 50g of table salt, dissolve it in 50ml of water, bang the container on a bible, or some other nonsense, then quaff deeply – vile right? Probably also a half way decent mouth wash – do not however attempt to disprove homeopathy by drinking gallons of the stuff – a 0X homeopathic solution is some potent shit, regardless of what a homeopath might tell you)

  8. Guys…remember that not all homeopathic products are diluted to the point of nothingness. The product in question, as Ewan rightly points out, is at a much higher concentration than some of the other products mentioned.
    I did acknowledge that the product claimed to work through dessication, but insects are pretty good at keeping themselves from drying out so I said I was skeptical of this claim without data. I also said that suffocation was possible, but that I was also skeptical of this claim due to lack of positive data from other suffocants. Ultimately, I concluded that data was lacking on this product due to a lack of publications in peer-reviewed literature.
    During the course of this project, I looked at the sources listed at the bottom. I went pretty heavy on the review articles in what I cited, but I did also look at primary literature. I’ll dig up the quote from the article which mentioned sodium chloride when I can. For now, I’ll list my search methodology.
    If you look on pubmed for ‘Sodium chloride AND lice’, there are no results found for organisms relevant to this discussion. Same for Teclabs, the company which makes the product in question. I also searched for the product name, and found no results. On, a search for ‘sodium chloride AND lice’, as well as Teclabs retrieves no results. Product names yeilded no results as with pubmed. There is one company with a similar name (Tech Labs) which is working on an unrelated project that I’ve hyperlinked at the bottom. I also crossrefrenced these terms in Web of Knowledge and found no results. In contrast, brand names and active ingredients (e.g. Nix, Ovide, Pyrethrum, Malathion) for other treatments yielded a plethora of scientific and clinical trial results and primary literature across the two search engines mentioned earlier as well as on in. Between the three academic search engines, the research I did on unrelated products, and the searches I did on this product specifically I didn’t find anything resembling data.
    I won’t, however, completely exclude the possibility I’ve missed something. I’m definitely open to criticism, and invite anybody to repeat the search with either the terms I listed above or their own terms. Pubmed is available to the public, although some articles may not be. I should be able to access articles so if anybody posts a reference there’s a good chance I’ll be able to access it.
    I will be in transit all day, so I will not be around my E-mail.
    If any commenter here wishes to repeat my searches in pubmed, I encourage you to do so and if there’s anything I missed post the reference and I will do a whole post on it. Post a citation, and I’ll look at it. If Dana will post a citation for any information I’ve missed I will issue a correction (if warranted) when I’ve had time to peruse the data.

  9. Dana, why not make the efficacy studies public? If I was selling a product, I’d want to show my potential customers that my product worked. Personally, I’d want to back that product up with a peer-reviewed efficacy study, but at minimum, I’d post the methods and results on my website.
    The Everyday Shampoo, according to the Licefree website, is “for the prevention and treatment of head lice infestations.” So, it is intended for treatment, correct? And the “active ingredient” is present in the shampoo at the same concentration (1X) as it is in the gel, which is “for the treatment of head lice, pubic (crab) lice, or body lice.” The spray has 2X. Is the spray twice as effective? Since the spray is “100% effective in killing lice and eggs” does that mean the gel is 50% effective? Just trying to understand things here.
    This all does make me wonder, if salt is so effective at killing lice, why parents shouldn’t just use salt water that they mix at home. Yet, is salt effective at killing lice? If it was, one would expect at least one published study showing its efficacy. It’s not like there aren’t any published studies of other naturopathic type remedies.
    Finally, if we have no proof of efficacy, what about safety? Regarding LiceFree shampoo (the one with the same amount of “active ingredient” as the gel), the National Library of Medicine at the NIH reminds us that Licefree “has not been evaluated by the Food and Drug Administration for safety or efficacy. FDA is not aware of scientific evidence to support homeopathy as effective.”

  10. Ah, some searching for “Licefree efficacy” did turn up one interesting document, which is posted on Tec Labs paltry Reports and Studies page.
    Efficacy of Lice Freee for Head Louse Infestations by Philippe Rossignol, Professor in the Department of Entomology at Oregon State, published as a technical report in May of 1999.
    First, let’s look at Dr. Rossignol. He seems to be a pretty well published scientist, at least based on PubMed results for his name. He also has a lot of publications on his website, although he doesn’t list the Lice Freee report.
    He doesn’t have any publications testing pesticide efficacy. The only mention of the word pesticide in his list of publications is an invited book review of Our Children s Toxic Legacy: How Science and Law Fail to Protect Us from Pesticides that appeared in the Journal of Public Health Policy in 1999 (the same year as the Lice Freee experiment). This gave me some caution, causing me to wonder if Dr. Rossignol is subtly anti-pesticide. After hunting down the review, though, I found that the review was quite critical. So, bias for or against pesticide does not seem to be a problem.
    Back to the technical report. Two obvious problems stick out. 1) The experiment was not conducted in the same environment where the lice live. A petri dish is not hair on a head. Would the gel stay at the needed thickness on a curved head, or slide off? This question is not answered in this study. 2) The amount of water (control) or gel in the petri dishes is not described in hard numbers. Was the level of water 2 mm and the level of gel 5mm? Were they both 5mm? Was it 3mL and 3.5mL? Did they wing it, or did they measure?
    These are major problems – and probably the reason why it wasn’t published in a peer-reviewed journal. The other strange thing about it is in the “Comments” section: “The product is clearly not a chemical insecticide treatment, as are other commonly available peiculicides, since it contains no active ingredient that comes under the definition of an insecticide.” Again, I’m sorry to pull out semantics, but salt is a chemical, and if it kills insects, then it is an insecticide.
    One other link that shed some light on the efficacy question is Faculty Discussion: Definitive Management of Head Lice in the Era of Pediculicide Resistance which appeared in the American Journal of Managed Care in 2004. It’s not a peer reviewed test, but does mention an evaluation of efficacy: ” Another product that is marketed OTC and claims to kill both lice and eggs on contact is Lice Freee!, a sodium chloride product. I was hired by a company that wanted to purchase this product and asked me to evaluate its efficacy. Another evaluation was performed by David Taplin. We both found that the product did not work. Since Lice Freee! has such impressive advertising and packaging, I called the FDA [Food and Drug Administration] to ask how the manufacturers could make claims that the product killed on contact when it does not. The FDA responded that the product is considered to be holistic, so it is not regulated as closely as pharmaceutical products, for example.”
    Lice Freee may be registered with the FDA, but that doesn’t mean that that the FDA evaluated the efficacy or safety. And, based on my research, and Joe’s research, it doesn’t look like anyone else has tested efficacy or safety either, at least not in any way that was publishable, and not in any way that the manufacturers want to publicize.

  11. The technical report claims to follow the protocol in the attached paper – it however does not, it adds a submersion step which completely submerges the lice – fair enough *if* one can assume total submersion of lice during the full treatment time.
    The report also assumes ovicidal activity without demonstrating it. Given that sans ovicidal activity a treatment is next to useless one would have thought this may be a rather important step – and it ain’t like it’s hard, there is head lice literature dating to the 1920’s which investigates just this (using salt water vs non-salted water at various temperatures and concluding that salt had no effect at the tested quantities (which if memory serves were not as high as 10%)

  12. Regarding the saline product in question:
    Note that the ‘active’ ingredient on the package was (probably still is) labeled as ‘natrum muriaticum’. This is a homeopathic term for sodium chloride. I’ve asked many nurses and physicians if they knew the meaning of the term. Invariably, the responses were blank stares, followed by snide remarks once they learned the translation. Use of this term may be a clever ploy to disguise the identity of the supposedly ‘active’ ingredient.
    I’ve lost count of the number of times during the last two decades or so someone asked me about salt treatments for head lice. There are products available composed of dried Dead Sea salts that could potentially have an effect. I’ve seen the ugly raw skin that resulted from users grinding the salt crystals on the scalp and then leaving them there for considerable intervals. I’m not sure if this was the intended manner of application, but I’ve observed it more than a few times. I suppose the salt crystals could damage and desiccate the lice, much as it did to the scalp tissue itself. I’ve also been asked how long one need immerse their child’s head under the water at the beach (or scuba diving) to kill lice and eggs, or if it mattered whether one did this in the Atlantic or some other ocean of differing salinity. My stock answer was that there was no evidence that this would be effective, and cautioned them as to pursuing efforts that would waste time and effort, and likely pose greater risk than doing nothing at all.
    A note regarding ovicidal expectations: Very few FDA-registered pediculicides are truly ovicidal, or at least in a meaningful way. Whereas one might get lucky in a few cases with a single treatment, success in eradicating head lice most often requires two well-timed applications of an efficacious formulation… and a population of lice susceptible to the ingredients. Ah, but the American public desires instant gratification, and wishes a product that is fully efficacious with a single treatment. I can think of many products (e.g. kerosene) used in the early 1900s and before that would likely be fully efficacious, but these are not safe now (nor were they then). Sadly, some folks still apply them – and at least a few kids each year suffer horrific consequences that burden them for life. It should also be noted that at least one FDA-registered prescription pediculicide new to the market has impressive ovicidal properties. Hence, there is a reasonable chance that a single application will be all that is necessary to eradicate the population from the treated scalp. Being that it won’t remove those relic dead and hatched eggs, some clinicians and many consumers might wrongly believe that further treatments will be necessary. That is akin to beating a dead horse. There is one fully efficacious ‘treatment’. Shaving the hair completely will instantly and completely (and non-chemically) eliminate all vestiges of current and past infestations. It is not technically ‘ovicidal’, but it will eliminate lice and eggs. I dissuade folks from going that route, but some still select this method, nonetheless.
    More discussion about other kinds of treatment strategies (enzymes, antibiotics, anti-parasitic drugs, heat, etc.) can be found at IdentifyUS

  13. Okay…so it’s a non-peer reviewed technical report I missed. I’ll have it up and add my comments by the end of the week.
    Just browsing the report, I see the things Anastasia mentioned but there’s one thing which immediately jumps out at me which invalidates this as a test.
    The criteria they used to claim that the lice were dead appears to be lack of movement. The author said lack of peristalsis, but didn’t specify peristalsis of what. Gut? Heart? Big difference between the two. Later, he said ‘lack of movement’ which is a completely different criteria alltogether.
    Either way, when lice are submerged in water they stop moving because they basically get knocked out. I use carbon dioxide to knock out bugs all the time, and water is little different except the insects have a harder time clearing it from their trachea which results in a bit higher mortality.
    So the lice stop moving quicker with Licefreee. Great. So what? What percentage of them recover after treatment compared to the control? Is this clinically relevant? These are the types of questions that would need to be answered with a report like this…and this report fails to do so.
    Also, and this is totally nitpicky and I don’t care because I get to use an entomological pun, but the control in this case should be the gel without the pediculicidal ingredient. Water isn’t a valid control in this case because there are ingredients like benzyl alcohol or fragrances in the gel which may influence louse mortality.
    That being said, this is a significant oversight on my part and I’ll correct it by critiquing it when I’ve got the time.

  14. OK, I’ll let you continue to beat me up a bit.
    The Licefreee Gel efficacy study is posted here
    We use the term natrum muriaticum because that is how we are REQUIRED to say it. Really, a ploy? (I realize that some of you think all companies are evil, but we really are in the business of helping people.) Licefreee is formulated under the FDA’s homeopathic drug regulations. Yes, there are rules we have to follow – especially how things are presented in a Drug Facts box.
    The product’s excipient base helps draw/deliver the salt into the louse. This is why “swimming in salt water” does not have the same effect.
    We do not hide anything. As soon as our current clinical trial is published, I will post a link here. You know that will take some time. I cannot give details in advance of publishing. You should know that as well.

  15. I wondered when looking at this before if benzyl alcohol would actually be more of an active ingredient, or the only potentially somewhat active ingredient–I’ve also wondered the same thing with the surfactant in the enzyme solutions. Isn’t benzyl alcohol being used as a 5% solution in Ulesfia? Although I’m guessing it’s used in this Licefreee formulation in a much smaller amount to function more as a solvent. But I also found it interesting as I read that benzyl alcohol is naturally occurring in ylang-ylang–an essential oil that seemed to generate some positive buzz (not sure how scientific in nature it was) at one point in the Hair Clean 1-2-3 formula which looks like it is now Nix PF. I’m not sure any of it amounts to much but it would be nice to know the bottom line, which seems to elude me when I’ve tried to find it!

  16. I’ll second the motion that cessation of movement or peristalsis are not necessarily sufficient indicators that the lice are dead. It requires continued observation to ensure that lice do not recover. Years ago I was asked to test olive oil as a treatment. I submerged a half dozen head lice in EVOO and noted that movement and gut peristalsis ceased within minutes. After an hour of submersion, I removed the lice and dabbed them on a paper towel. Within minutes several of the lice became active again and began moving about on the towel. These were submerged again for another hour, after which they never recovered. I never replicated the tests with adult, nymphal or embryonic lice. The results were, of course, not publishable (nor was that my intent). Not surprisingly, a group that advocates use of olive oil for treating head louse infestations exaggerated the significance of my observations.
    Re: Natrum muriaticum. Does FDA specifically prevent the label of a homeopathic formulation from stating that natrum muriaticum is salt? I just read the FDA guidance and failed to see that the term ‘salt’ is prohibited. If I missed it, I’d enjoy being corrected.

  17. I don’t know if the FDA says you can’t say salt. That I would have to defer to my regulatory dept. However, on our label we have Natruum muriaticm (Sodium Chloride) and all physicians I know recognize sodium chloride as salt – at least all of the ones I’ve talked to. Most, not all, physicians receive our product well and many recommend it.
    Our labels are written to follow FDA guidelines.

  18. From Tec Labs (Licefreee) site:
    “If an outbreak does occur, treat with a pediculicide making sure to take it slow and follow all directions completely. Carefully remove all dead lice and nits after treatment with a nit comb. Even if all lice and eggs appear to be gone, following through with a second treatment within 7 days and random head checks can prevent future reinfestations.”
    I’m not sure if they are referring to their own product as the pediculicide, but this leads me to believe that the comb is doing the work–the gel is just doing what olive oil or any other solution to the head would do–temporarily immobilizing lice so that they are more easily removed manually.

  19. I would hazard to guess that using the term natrum muriaticum is to stay in line with the homeopathic labeling on the product. By federal law many years ago, homeopathic products already listed in the Homeopathic Pharmacopeia of the United States were grandfathered in under the 1938 Federal Food, Drug, and Cosmetic Act and are thus not held to the same standards as other drugs.

  20. OK, my last post for you all.
    Here is the non-scientific scope of what parents are dealing with.
    The standard pyrethrum and permethrin treatments from forever ago are no longer working as well as they used to. Spend a day in our office listening to the parents calling in tears because they have been using these products and fighting with lice for months. It drives them literally insane. On top of that their child has the “dirty lice kid” stigma so their friends are avoiding them. Child and parents are miserable.
    With the no child left behind rule, and with AAP sending out a formal statement earlier this year that head lice are not a health hazard, schools are dropping their no-nit policies. Kids are being sent to schools with nits in their hair and it just takes one to hatch and start it all over again.
    I’m sure the new prescription drug referenced above is probably fantastic, but I’ve been told (by the physicians I’ve spoken to) it costs over $100 per treatment. I’ve also been told it is also not covered by insurance. Therefore doctors are hesitant to prescribe it because they know most people can’t afford it.
    Therefore parents are turning to non-traditional methods to beat head lice. Everything from olive oil and mayo to the non-toxic’s sold over the counter. Parents are just simply frustrated and looking for a method that works for them. And most parents work and don’t have time to spend days and days combing out nits and lice.
    I am happy that we are helping people whether or not you believe we are. See, we also get the happy calls and emails thanking us for finally solving their problem.
    I expect you, being of scientific minds, to be skeptical. So again, I encourage you to test our product. The best proof is seeing it work.
    Have a great one.

  21. Dana, perhaps you could comment on the useage of the term homeopathic here, frankly that is likely raising as much ire as anything else (I’m not wholly convinced that a 10% salt solution in a gel format would kill lice, but I’m not totally sure it wouldn’t either – 10% saline could potentially impart osmotic differences which would suck an insect dry if the application was correct – and is much higher than sea water (~3% according to the fine folks at Google U) ) – what bugs me is the notion that a 10% sodium chloride solution is homeopathic. First – it doesn’t appear to even remotely go along with the principle of like curing like, which is a pretty central part of homeopathy, and second a 1X or even 2X mix seems practically at odds with homeopathy also, if the mix is truly homeopathic why don’t you provide 5X, 6X or 100X mixes – potency increases with dilution (if you’re a homeopath) – aren’t you simply circumventing the requirements for proper testing by claiming your product is homeopathic rather than being designed as a real treatment.
    Truly this is where a lot of the ire is coming from. You simply cannot be expected to be taken seriously by anyone of remotely scientific bent if you go around actually believing that homeopathy works. Frankly I’d be more willing to take claims seriously if you were to simply state “yeah, we’re a small company exploiting a loophole by which modern day snake oil avoids regulation due to the widespread knowledge within regulatory circles that it cannot possibly have any effect whatsoever – because if we didn’t our product would cost too much to bring to market” – at least then you appear scientifically grounded and business savvy, rather than nuttier than squirrel wossnames.

  22. Dr Mark Christensen formulated this item under proper homeopathic guidelines. We have other homeopathic as well as standard OTC drugs in our product line. All follow guidelines, rules and regulations. We never exploit anyone ever and I resent that you would insinuate such a thing. Our company is very highly respected.
    Nice job trying to bully me. Name calling really isn’t necessary is it?

  23. Dana, “proper homeopathic guidelines” is really meaningless since homeopathy is based on complete pseudoscience. Homeopathic formulations were grandfathered in to the 1938 Federal Food, Drug, and Cosmetic Act as a result of political influence, not because of any scientific evidence of efficacy.
    As far as we can tell, there is no good evidence that the product works. The methodological issues with the single technical report was were pointed out by Anastasia earlier. Other than that, all that has been provided are testimonials, which are well-known for not being reliable.
    I would think that it would be in your company’s best interest to conduct solid, reliable tests to show the product’s efficacy and publish the results in a peer-reviewed journal.

  24. Again, there is one currently underway. *smh*
    Ok, I’ve got work to do guys. I will post the link when its out there. Until then there is nothing else I can say.
    If any of you really want to experiment with the product at any time, let me know. I’ll send it to you.. If you want to talk to someone in the lab, I can do that for you too.

  25. Name calling? If you truly believe that homeopathy is a valid form of medical then being called nuttier than a squirrel wossname is not name calling but simply an accurate description.
    All I’m suggesting is that the company is exploiting a loophole in the law to circumvent having to go through medical regulatory procedures to bring a product to market, not exploiting any people (if the product works then you’re not exploiting people per-se, although if the homeopathic tag is also a marketing gimmick then this is exploitation plain and simple – just as it would be exploitation if Bt corn were sold under the guise of working via voodoo (still works, but those selling it would be exploiting folks belief in the absurd to make sales))
    I see ire in many of the above comments, as I’m sure you do too (unless you’re redacting your “beat me up a bit” comment) – I actually felt I was being less harsh in my approach than others.

  26. People above were tearing apart the efficacy study, isn’t that what you all do? I’m ok with skepticism. They aren’t attacking me. I only have the tools I am given. I’m obviously not at your scientific level.
    At the end of the day I help people.

  27. What you call “tearing apart” were simple critiques of the technical report. Yes, that is part of what scientists do and what we expect other scientists to do to our reports. Vigorous and demanding criticism is important. If a report cannot stand up to such criticism, then its results are not as reliable as they could be.
    Peer reviewers for scientific journals are often far more aggressive and demanding than the basic criticism shown here. It hones experimental design to help produce more rigorous and reliable results. It is not something to be avoided, but something to be embraced.

  28. Please don’t get upset with me. I agree with you- I expect and respect the criticism.

  29. Dana, first of all, no one is beating you up. We are looking at published information (and lack thereof) which has nothing to do with you as a person. No one is beating up Lice Freee or Tec Labs, either. We are commenting on the available science. The only available science, again, isn’t peer reviewed, has huge methodology problems, and was not accessible from the Lice Free site. It is indeed online, but it was not posted anywhere obvious – not quite hiding, but not proudly presented, either.
    These products have been around at least since 1999 – so is it really so strange that anyone would question why it would take so long for a clinical trial or published study? Is it really so strange that anyone would question why an ongoing clinical trial isn’t posted on
    One thing I would love to see is some explanation of what the FDA regulation you speak of entails. According to the National Library of Medicine, homeopathic products are not evaluated by the FDA, although they may be registered with the FDA. Does simple registration count as regulation, or is some sort of evaluation needed to call it regulated? I’m just not sure how this works for homeopathic products.

  30. Could you please answer one more question?
    Why has your company waited until after the product was on the market before conducting an efficacy trial?

  31. It seems that “homeopathy” doesn’t have just one meaning. The “true” meaning perhaps is the dilution one but others just use it to mean herbal or traditional remedies. What I want to know is what definition the FDA uses. Because if they’re using the herbal definition, then Lice Freee is good to go, but if FDA is using the dilution definition, then there’s something squirelly going on, indeed.

  32. Two reasons. Lack of budget and finding the right facility to do it (mostly budget). It’s a miracle we have been able to survive in the retail market with what it costs to stay there.

  33. I tried to find some sort of clarifying documentation but I cannot find anything to explain online. My point was just that we do have rules to follow, we get regular inspections and visits. We are not a fly-by-night bathtub operation. I was just trying to explain we are a valid company held to rules and regulations. That is all. Yes homeopathic’s are treated differently.

  34. From my understanding, the FDA is going by what was included in the Homeopathic Pharmacopeia of the United States at the time of the 1938 legislation. Even in that work, some of the included materials were mixed in dilutions that would include a potentially active quantity. For example, look at the Zicam problem from a couple of years ago when a homoepathic nasal remedy had enough active ingredient present to cause side effects up to the permanent loss of the sense of smell.

  35. I just have to say, I find you all fascinating. I feel like I should send all of our testing your way. Thank you for your patience with me and your time. It truly is very educational.

  36. I should do a methods post, that is a post where I discuss methods instead of results which is kind of unusual for me. There’s a paper in PLOS one that I’m going to hit, then I plan on coming back to this.
    Dana, I would look into the work of Deon Canyon and Rick Speare. They are doing really good, stringent work on head lice treatments.

  37. Thank you Dana! I’m so very glad that you’ve stopped by and stuck around.
    Scientists and science-minded people can often be a bit vigorous in our criticism of ideas, but it’s important for that criticism to be targeted to the ideas, not the person (which we seem to be doing pretty well at in this comment thread – I hope you agree!). And, we have to be ready to have our ideas torn up when our turn comes around. I’m eagerly anticipating and yet not just a little nervous of when the 2 papers from my thesis are published. 🙂

  38. Thanks for your interesting (and convincing) posts on lice remedies! After reading them, there is still something I am not completely sure to understand. There is an explanation on the “modes of introduction” in the context of “natural” insecticides and questionable remedies but how does it work for the FDA-approved products described in the earlier post? How are pyrethrum, lindane or malathion acting on the lice nervous system when applied in a shampoo? Is it also possible to administer these or other treatments orally (i.e. via the blood of the host)?

  39. Many years ago, when my mom was a barber, she regularly used a shampoo with *acetone* as the main ingredient. Occasionally a customer would show up with so much Bryllcreme (R) (for that ‘slicked back’ look) in the hair that it was the equivalent of it being soaked in Vaseline (R), and therefore not amenable to doing a proper haircut. The acetone effectively wiped out all the grease.
    I have to wonder if acetone shampoo might not kill head lice, their eggs, and about anything else that might be nesting up there.
    She used it on me once after a hazing incident at the local high school that involved coating my hair with Vaseline (R) and rubbing it in thoroughly. The acetone vapors were so intense it was hard to breathe. But it worked!

  40. The challenge for products like Licefreee is that it would cost quite a lot to do the FDA required clinical trials, and if they are successful, we would all know that we could use table salt and water already in our homes to get rid of lice so no one could recoup the cost of the studies. It is unfortunate that for many medical conditions there is evidence that inexpensive, non-patentable remedies may be effective but there is no source of funding to determine if the treatment is actually safe and effective.

  41. *read my disclaimer* Don’t try anything here I suggest it’s just for reference only* or try at your own risk!* First, thanks Joe for writing your blog. So far yours is the best link in my little collection of links. I am likewise skeptical of all claims until proven and even then I like to track them over time because sometimes a new twist is added to revise my thinking. Like Anita just mentioned, I found examples of companies selling cheap materials available to anyone but marketing them at high prices. One comment 3/24/2010 by a patient Cassie here tells of simple lotion being sold for 100/bottle 800/family in their controlled study. I’m not a scientist although I do have a BS in biology but don’t use it (computer technology – train and troubleshoot). My biggest surprise is how few people do or write any quantitative analysis or write in more detail their observations. I’ve read 300 opinions but found 0 tests. So here’s mine – remember, I’m not a scientist just a Dad. I have 5 kids and this is my 2nd bout with lice. Last time 10 years ago I also tested some lice in oil (in vitro) and similarly found they ‘revived’ after 10 minutes out of it. I lost my notes on the experiments I tried then but I remember trying hot sauce, oil, water and found nothing really killed them but oil made it hard for them to move fast. My solution that time with 4 kids was to soak in oil for 10 minutes then comb comb comb. repeated daily for 2 weeks and it just about killed me in time! This week 2 kids have it again! New testing. I read two links suggesting that lice can shut off their trachea for 30 minutes and no food for 55 hours. I can’t remove food so I tried the no air – 35 minutes failed to kill them at all as I found 10 from combing. (I gave up on snorkeling after a few minutes as too hard. easier to lie on a raft in a pool but a waste of time) Next I made 5 test tubes from some plastic tube. My lame attempt at simulating the head was to give each louse a single human hair and make sure they were attached before pouring. For all I submerged them completely. All observations were under a microscope. I put in: 1. nothing, 2. water 3. oil, 4. apple vinegar 5. lotion 6. iodized salt in 1/3 ratio. After 10 minutes I observed no movement from any of them. In water it looked attached by head and bubbles around it. The vinegar one had floated initially so I pushed it under which made it move vigorously then stop. I pulled them out and placed on clean petri dishes to dry out. 25 minutes later I noticed all were unresponsive but the one in water was moving. I waited 9 more hours and found both the water and lotion one were moving fine and you could see the food going back and forth. The vinegar, salt, and oil were all dead. oh, one problem, my control with nothing at all was dead. I had not meant to use it so did not check when it died but that serves to show using too few can lead to lots of erroneous thoughts. Any one could have died from abuse by my tweasers instead of the medium. Next I tried a single lice in saltwater and one in saltwater + vinegar for 2 minutes submerged then out to dry in a dish. The saltwater/vinegar moved right away and continued through well past 15 minutes. the plain salt one started moving after a minute and refused a human hair – it moved vigorously as if in pain trying to wipe the salt off perhaps. After teh 7th minute it stopped moving but I could still see food in gut moving. it never came too and eventually shriveled. My temporary conclusion was that salt is more effective at very high concentrations. Next, for my kids I soaked their head in a pan of saltwater. I only put 1 cup into 1.5 gallons of water. After 30 minutes, I put oil on their head and began combing (oil just to slow them down). I found 6 dead and 9 alive (most from nape of neck where perhaps saltwater did not reach well?). I lost 2 so had 7 to observe. after 2 hours 2 vigorous, 4 legs moved, 1 nothing. After 2.5 hrs 1 vigorous, 1 some, 5 dead. after 10 hours 2 had some movement and 5 dead. Anyway, I hope this level of detail helps someone out there. I’m going to continue to test and see. One big drawback is that I don’t have many lice to test on. One positive is that by testing on your own child’s head lice, you know what is or is not working on their population of lice. Any chemical in the store may well work on most populations but why not try it on your child’s lice and see how it works. I did buy an OTC lice treatment 10 years ago and applied liberally but regretted it as I tested it ‘in vitro’ and after 15 minutes submerged it was very much alive and next day. So just because the bottle says it works observation is king! I find so few people just try things even in technology asking if this or that will work. It takes longer to research it than to try. However, NEVER try anything that might hurt yourself or your kids! **Disclaimer** don’t try anything I suggest or do so at your own risk** Beware of ‘harmless’ ‘natural’ remedies. For example, some bath salts have been made that cause hallucinations or worse. Also, never leave your child near water without constant supervision!

  42. Just as an update, I tried a stronger saltwater solution this time of 2 cups/gallon and was very disappointed to only find 3 dead and 21 alive, worse than last time. I was about to throw in the towel on saltwater too since mechanical removal really seems to work best anyway but I checked back after 5 hours . . . wow, 24/24 were dead! I was surprised by this – I expected some to die only. I think saltwater in very high concentrations may well work. Now don’t go selling this stuff – people should have a cheap solution to an annoying problem. Combs are king to me, but I’m feeling that there is a place for saltwater to be considered. More research of course needs to be done on a bigger scale – perhaps one of you real scientists can find some current research with HIGH concentrations not 10% solutions. Good luck!

  43. I enjoyed reading the details of your home experiment! Thank you for posting. In Germany they sell the metal combs with a Natron powder…baking soda and salt, to mix with water and apply to the hair. I read that natron was also used for mummification?

  44. Just a final followup. I did the same procedure on my daughter’s head (my son’s had the 24/24 dead) and did not find any that day but the next day I did 3 cups salt/gallon water and found one large lice. I know it was a lice under microscope. I often remind family and friends that ‘correlation does not imply causation’ but I know so well how easy it is to fall prey to this thinking – ex, the salt correlated with them dying so I assumed ‘salt kills lice in high concentration’ but a single counter example refutes this whole idea –
    Maybe the 24 lice were weakened already from other things I did. Maybe they were a slightly diff population than on my daughters, maybe younger lice are more susceptible to salt but not older ones. Maybe the weaker lice were selected out and one lice had a little more waxy protection. Many other possibilities exist. All I know is I combed again w/o anything (on vacation)2-3 times through the 29th and found nothing. I did a followup today, 10th, and again found nothing in either head of hair nor eggs. That’s nice news but strange to me: ex, if it is true that mature each lice can lay 10 eggs/day and I had 24, even if only half 12 were mature enough, that’s 120 new lice x 3+ days they had so 360 eggs! I did not find that many and there’s no way even my fine tooth lice comb (recommend hightly 2 sided comb) could have gotten all of them. It seems lice should have the advantage for longer than I had to comb. Hopefully I won’t have another bout with this for another 10 years but when I return here I hope someone else can do some experiments and find more results than I.
    For now, I’m acting on these assumptions: 1. combing is king – do it with course then fine tooth comb WITH WATER RUNNING! The salted hair was way too painful alone! I added oil to help but nothing but conditioner makes it easiest to comb. The more combing, the more I got period. I may still use the saltwater but I’ll comb only with lot of conditioner on hair to make it as painless as possible! Take care and good luck, JT.

  45. As a lice treatment professional, I have been researching better treatments. I invested in Lousebuster which I decided I hated. Having lice myself, which was the inspiration of my career, I tried Licefreee. I was effective. Not 100%. My lice did return but it inspired me to make my own salt solution with no exact measuring. I had a squeeze bottle similar to hair dye applicator. After I left my primary job, I was home full time. I had time to work on my lice. After putting the salt solution on my head, the lice did stop moving and my populations declined. So for my conclusion only, I decided that if I maintain applying my salt solution, leaving it on as long as possible during each day, I can kill the alive lice, so that eventually all the nits will have hatched, with no further lice reproducing. Additional research for natural products suggest that a 3 week process of regular treatment can have successful results. I haven’t been able to complete a consistent 3 week treatment but I am optimistic it will happen because nit combing is out of the question for my hair type.
    Licefreee’s video shows lice dying within 3 minutes of direct application. The product is never applied in that fashion and is ineffective against nits so a 2 treatment package, I have concluded is an unrealistic product that is only helpful if extensive nit combing is included but if nits are missed then we are at square one once again. The nit combing is part of Licefreees treatment and they include a high quality comb. I struggle because of my long hair and texture. I can’t GET A HAIR CUT WITH LICE!!!

  46. In response to JT’s experiments, I would like to share that my personal experience with salt (June/July 2012) was consistent with his findings.
    I too am a scientifically minded father (software engineer) who joined the ranks of parents having to deall with head lice on my children. I had never experienced lice first hand in my life. In the late spring of 2012, my older duaghter began complaining of an itchy scalp. For a time my wife and I dismissed it as dandruff, but at one pioint I became suspicious, so we pulled out my wife’s high school microscope, and I witnessed for the first time the structure of a nit on a hair. My first reaction, before I knew what I was looking at, was that this had to be biological– no random piece of dandruff. It was shaped like a tulip or canister with a stem on one side that encircled the strand of hair. I quickly identified it online as a hatched nit, or louse “cacoon”. Unfortunately, the younger daughter was infected as well. There began our saga with lice. They are indeed formidable creatures!
    We went immediately to defcon 5, doing hords of reasearch, buying the expensive chemicals (Nix), and a nit comb, vacuming floors, washing sheets, putting suspected infected items such as pillows in plastic bags for suffocation over a couple weeks, etc.
    We monitored daily, combed through hair removing lice and nits religiously, and slowly we were winning, so we thought, but we couldn’t seem to put the nail in the coffin after several weeks, no matter our level of diligence.
    We even tried extended hair dryer treatment– moderately effective in some NIH studies. This was hard for the kids to endure. It seemed to help, but it was not a final cure.
    For some time, I had been thinking about salt. It had occured to me that salt kills bacteria by dehydration, so why not insects?
    It was nearly impossible to find much on the Internet that would corroborate my hypothesis until I encountered JT’s post on this web site (thank you JT!!)
    My primary concern was safety for my children. While salt seemed harmless at first glance, I wasn’t sure what concentration would be required to be effective agains these pests, how effective salt would be, nor what exposure time would be requrired.
    I was also unsure about whether a high concentratiosn would be harmful to human skin, or the scalp in particular. However it suddenly occured to me that people bathe in the Dead Sea, and I hadn’t heard any reports of skin burns from that activity. Dead Sea water is of course, due to eons of evaporation, as fully saturated a salt solution as water will hold at ambient tempuratures. And the more I read about salt and skin, the more I found it reported to have theraputic prorperties for a whole variety of skin conditions.
    After reading JT’s posts, I was convinced. We boiled a pot of water and added enough salt to reach saturation point (~30%) and let the solution cool. We poured it into a basin and soaked the kids hair in it for 30 minutes. We then towel dried their hair and let the remaining salt water air dry and crystalize in their hair. This was morning, and we left the salt in their hair all day, until their night time bath.
    There was no discomfort for the children, and their hair looked rather sparkly / glittery with crystals, so they even enjoyed it! 🙂
    For at least 10 days following, we checked for lice and nits. We found a couple dead lice and some nits the next day, and just a couple of nits but no lice the day or two after that then nothing. That was the nail in the coffin.
    While I cannot rule out the combined impact of measures we took prior to this approach, I strongly suspect that the salt treatment would have done the job without all the painstaking conventional approaches that certainly improved things, but repeatedly failed to finish the job.
    Best wishes to all who struggle with this pestulence.
    I hope my anecdotal evidence and JT’s more controlled experimental evidence prove helpful to all.

  47. I’m not scientific or the writer of some blog. However I am the mother of a child that had lice. I looked on Amazon to read the reviews of the products and LiceFreee had nothing but rave reviews from everyone. I went and bought some and it so far has done what it claims to do. Dana is right, the product works.

  48. Dear Joe Bellanger: I am fron Nicaragua CA, and I have experimented with quassi amara products, and in a water quassi amara solution , home made, we had control lice in children , is a common medicine here en CA, all the way to Brazil. I have used it , the QA,to control Avarroa in bees, will you be interested to see the University Thesis of some new Vets?my e mail is, my name is Gustavo Cordova , I am a graduated from UC, 1973

  49. Do enzyme products work? I can only find info from the producers of the enzyme products themselves. Thanks for your help

  50. I have the same question as AK.
    I’m wishing there were clinical trials on the efficacy of protease-based enzyme “shampoo”s,
    but I don’t see any, other than one showing that you don’t want to get them into your eyes.
    In the absence of experimental verification, do they have a reasonable mechanism, from an entomological point of view?
    I would love to hear this from an entomologist’s point of view.

  51. Dana, if you see this I want you to know that I am one of the parents that has had I credible success with your product. After years of battling head lice in all three of my girls, I can not thank you or your company enough!!!

  52. I agree that the salt-solutions sound unlikely. But we have had much success with lice freee. Just one time we got a bottle that didn’t work and it smelled obviously different so I am sure it was just a bad batch. I like how it even manages to work when I don’t have time to pick all the nits. The kids stay lice free until the next big breakout at school.

  53. Dear JT and Steve: Thank you very much for your testing and information. I am on my second bout of lice with my twins in 2 months (following 2 separate visits from the same cousins with what were described as “long term” infestations by a lice removal professional). In the first infestation as well as this one I used an OTC product (Rid, I believe) to at least aid in reducing the hatched population, followed by a few weeks of daily combouts and daily laundering/heating in the dryer of bedding and clothing. I’ve been wondering about the possibility of using salt as a dessicant (and more hopefully — wondering whether or not it might dessicate the nits), and you both have provided more information than I’ve been able to find anywhere else so far. I was hesitant to try salt on my children without having any idea if certain salt solutions could be irritating (or be absorbed — especially without knowing how long the solution would need to be applied) — and at least y’all have given me some ball park info. Thanks very much.
    Someone had mentioned Americans wanting instant gratification (not sure it was meant in a bad way), but I certainly see the need for a one-step product for lice. In the case of my own dealings with lice, the cousins who were found to have long-term infestations share their time between three homes (separated parents and grandparents), and all it takes is one weak link in the chain of treatment to keep that infestation going. I’m lucky enough to be a stay-at-home mom with enough time follow through with treatment recommendations. Few people have the luxury of the time and effort it takes to treat lice — it is very easy to understand how these infestations persist and spread. Even if a one-step treatment left dead nits or cases, at least the ability to spread the lice would be diminished or eliminated.
    Thanks again!

  54. I regret that I did not have the opportunity to read this when it first came out but feel that our response is necessary. Joe Ballenger, as he pretty much admits, has no idea how X-PEL Anti-Lice Shampoo & Conditioner works. He obviously has not read our claims since he somehow believes that our video is showing lice being killed. We make no claim to kill lice or eggs. We claim, as the video distinctly shows, to eliminate lice. In addition to the shampoo, combing is required to remove nits and any remaining lice. Thousands and thousands of bottles of X-PEL have been sold throughout the U.S. for over 8 years and it is continuing to help people. Joe, you don’t have to kill lice or nits. You need to remove them so that they don’t continue to breed. If it makes you feel better, once they are removed they will die.

  55. I think Joe’s argument was that no good evidence was presented that the product works as described. Quibbling over whether you claimed that the lice in the video are killed or not is beside the point.

  56. Yeah, I should probably return to this article…shouldn’t I? Lots of people have posted questions, while I’ve moved on to other projects.
    Basically, I questioned whether there was a reasonable hypothesis behind the ingredients used. Phenol, sure…that stuff will kill anything. Rhododendron and ground up bees at super-low concentrations? I’m just skeptical.
    As for the claim that the shampoo will wash out lice, is there evidence that it works better than a shampoo which isn’t advertised for that purpose? The video doesn’t give any real data, which is what I concentrated on.
    I didn’t say that I had no idea how it worked, I said that the website and video didn’t give me any reason to think it *would* work better than non-pediculicidal shampooing and conditioner. There’s a difference between the two statements.

  57. Joe,
    Did you read the paper published in Pharmacology & Pharmacy linked above in a comment from last year (comparing permethrin to the sodium chloride spray LiceFreee)?

  58. Joe, thanks for the blog. I don’t usually comment on these things, but thought I might add a bit to the fray. As a mom of 12, I have had to deal with these pesky creatures from time to time. In the distant past when my older children were in school, the 70’s and 80’s, the products out there worked. I had a system for cleaning and treating that was fool proof. The laundromat and I were best friends. One fell swoop and everything in the house was at the laundromat, in a garbage bag in the cellar awaiting the end of its mandatory quarantine, or at the curb in a can. I was fanatical. While we were at the laundromat, I “bug-bombed” the house, then it was off to Pizza Hut for dinner to wait for the bombing to be done, and maybe wally-world or a movie to round out the night.I could treat them all and be snuggled in bed that night knowing my whole house, and everyone in it were clean and fresh. Then we successfully managed to kill off all of the normal lice, and were left with the ‘super-lice’. Now it’s a nightmare. I have tried every potion both chemical and “homeopathic” known to man to no avail. My youngest daughter (did I mention the fact that we both have rather long hair) very kindly brought home “friends” from a teen gathering. There was a picture booth where the kids swapped hats. I was not there to freak out, and she had not been subject to these lovely creatures. That was November…this is August… I am at my wits end. Well then is not now. I have yet to win the war. After trying everything short of kerosene and a match, I was at my wits end. Then, last month , I was in Wally-world and found a new to me product, “Vamousse” brightly packaged,with a magic ingredient I had never heard of before, “Natrium Muricatum 2X”, The box claims it kills 100% of Lice & Eggs in 15 Minutes!!! Sounded impressive, so at 20 bucks a pop, I bought 2 boxes, and a robi comb. Cost me about $60 bucks for the lot. I figured it was worth it if it would finish them off! (If I can’t kill them any other way, a bug zapper for your head is worth a try I guess, problem is, the teeth are too far apart for the nits in my daughters fine hair! It just passes right through, no zap noise , no recognition of a nit a louse or anything, nits still visibly attached to the hair shaft! AARRGGHHH!!!!) Well, I hurried right home, did my cleaning regime again, and we treated each others hair, and even did the comb through with the supplied comb. It smelled great, our hair was left soft, it was wonderful….and then, the next morning, I was relaxing drinking my morning coffee feeling like all was well in the world, when I felt something moving in my hair… I was thinking ah, it’s only your nerves, and then it bit me! Yes I am one of those blessed individuals that can feel them crawling and biting, which probably accounts for some of the reason I’ve been so cranky lately. I was NOT happy. My daughter kindly checked my head in the area that I felt the biting, and lo and behold,she saw, not one,but TWO of those nasty little creatures zipping through my hair. I was livid! I could MAYBE understand a stray nit or two, but LIVE crawling ones?!? 100% my foot! I looked up what that ‘miracle ingredient’ was online, to find it was just plain old salt! I called the Vamousse people, of course it was an answering machine,I left a very unhappy message. Within 10 minutes the PR guy called back. I asked him how I could have LIVE ones if it killed 100% of the lice. His answer? Sometimes after they’re dead a little while, THEY COME BACK TO LIFE! SERIOUSLY??? Do you believe it?? Resurrected lice? Does that mean we will be dealing with them in heaven? So I say, it doesn’t kill them dead, it just kills them to almost dead? He said, sometimes it just stuns them, take the product back, Wally-world will give you a refund, and we will send you 2 new cans by next day service, please re-treat” Well I was foolish enough to do it all over again, and… it still didn’t work and I am out over $100 on the cleaning costs for those 2 fiascoes, Live and learn……So 100% doesn’t really mean ALL of them, and ‘kills’ doesn’t mean kills them dead, just MOSTLY dead.(Sound’s rather ‘Princess Bride-ish’ to me) So ‘Vamousse’ is another product you may consider checking into. He (the Vamousse guy) says it’s been flying off the shelves since they put it on the market. I bet they are laughing all the way to the bank. Sometimes I just feel like crying. When I’m not busy scratching.. We have done Cetaphil, olive oil, diatomaceous earth, mouthwash, alcohol, vinegar, Nix, Rid, Heat, Tea Tree Oil, everything I can think of. Any Suggestions? like I said, kerosene and a match are looking really good. If it were you what would your choice be? One of my professors in college was an entomologist, so I respect your educational background. I haven’t a clue how to research this one. Thanks.C

  59. I don’t know much about science and data, but Licefreee works. A simple check of sites like Amazon, Walmart, Walgreens, etc would reveal the overwhelmingly positive feedback about this product. Frankly, I’ll take that any day over all the “science porn” going on here, but there has indeed been a study showing Licefree to work significantly better than the classic otc remedies like Rid and Nix, and to be just as effective as most prescription meds.
    Also, for all the talk about salt and sodium on here, it seems everyone failed to notice and/or mention that the first listed and most prominent in-active ingredient is Benzyl Alcohol. Benzyl Alcohol is approved by the FDA for lice treatment, and it is also the main ingredient in the prescription lice treatment Ulesfia. The stuff works.

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