When homeopathy is approved as an insect repellent, there’s a serious regulatory problem

Mozi-Q won't protect against mosquito bites

Given their visibility in the pharmacy, a recurring topic of this blog are the category of products deemed “natural health products”. My philosophy towards their uses has changed over the years, and what was an “evidence-based” approach is now firmly a “science-based” approach. A central principle to science-based medicine or pharmacy is that all health interventions and treatments should be evaluated based on a single, scientific standard. One of the biggest successes of the alternative medicine industry, worldwide, has been the embedding of different regulatory standards for the evaluation and approval of so-called “non-drug” products such as supplements, herbal products, and non-scientific treatment systems like homeopathy or traditional Chinese medicine (TCM). The implications cannot be overstated: this different and lower standard is now so firmly entrenched in most health systems that few seem to question its rationale, or consider the consequences. As a practicing pharmacist I spent the first decade of my career working within this regulatory framework without ever stepping back to question why we regulate some products differently.  Comparing two countries illustrates my point:

While the FDA and Health Canada share similar drug approval processes, they differ dramatically in their approach to homeopathy. The American Dietary Supplement Health and Education Act of 1994 (DSHEA) is an amendment to the U.S. Federal Food, Drug and Cosmetic Act that establishes a regulatory framework for dietary supplements, but not homeopathy. The National Center for Complementary and Alternative Medicine (NCCAM) points out,

Homeopathic remedies are regulated as drugs under the Federal Food, Drug and Cosmetic Act (FDCA). However, under current Agency policy, FDA does not evaluate the remedies for safety or effectiveness. FDA enforcement policies for homeopathic drugs are described in FDA’s Compliance Policy Guide entitled Conditions Under Which Homeopathic Drugs May be Marketed (CPG 7132.15).

FDA allows homeopathic remedies that meet certain conditions to be marketed without agency preapproval. For example, homeopathic remedies must contain active ingredients that are listed in the Homeopathic Pharmacopeia of the United States (HPUS). The HPUS lists active ingredients that may be legally included in homeopathic products and standards for strength, quality, and purity of that ingredient. In addition, the FDA requires that the label on the product, outer container, or accompanying leaflet include at least one major indication (i.e., medical problem to be treated), a list of ingredients, the number of times the active ingredient was diluted, and directions for use. If a homeopathic remedy claims to treat a serious disease such as cancer, it must be sold by prescription. Only products for minor health problems, like a cold or headache, which go away on their own, can be sold without a prescription. [emphasis added]

What NCCAM doesn’t mention is that homeopathy is an elaborate placebo system, where the “remedies” lack active ingredients. As would be expected with inert products, clinical trials confirm what basic science predicts: homeopathy’s effects are placebo effects. Yet these placebos, because they’re labelled “homeopathy” are regulated as drugs. Amazingly, the the regulations delineate some homeopathy products as “prescription” and some as “non-prescription” based on what they’re being used for — not based on what they contain. Which is odd, because homeopathic remedies are chemically and therapeutically indistinguishably – they are inert.

Nonsensical? Yes. But that’s homeopathy. To the FDA’s credit, they don’t waste resources reviewing products before they’re sold, and they explicitly don’t vouch for safety and effectiveness. Now compare this approach to Health Canada’s Natural Health Products Directorate.

The Natural Health Product regulations, under Canada’s Food and Drugs Act, regulate homeopathic products as well as many of the products Americans regulate under DSHEA: nutritional supplements, probiotics, traditional Chinese medicine, vitamins, and herbal remedies. They are a deliberate shadow of the regulations that govern drug products — requiring some manufacturing quality and safety standards, while effectively removing the standards for product efficacy claims. Yet Health Canada insists that this doesn’t compromise quality, safety, or efficacy:

Through the Natural Health Products Directorate, Health Canada ensures that all Canadians have ready access to natural health products that are safe, effective and of high quality, while respecting freedom of choice and philosophical and cultural diversity.

The consequence? Regulation of the absurd. Health Canada reviews every remedy, and explicitly attests their safety and effectiveness. In Canada you can purchase Health Canada approved (Search each product by number here):

  • homeopathic sea water — DIN-HM 80017767
  • homeopathic insulin — DIN-HM 80016480
  • homeopathic granite — DIN-HM 80012752
  • homeopathic roasted sponge “Spongia Tosta” — DIN-HM 80011377
  • homeopathic chloroform DIN-HM 80010524
  • homeopathic table salt DIN-HM 80005389

There are hundreds more, including more well known products like Oscillococcinum and Traumeel, all deemed safe and effective.

It’s easy to laugh at the irony of homeopathic water, and the while the sale of these products by pharmacists is certainly unethical, when used for self-limiting conditions, the risk of harm may be slight. But a framework that gives even a veneer of credibility to sugar pills increases the perception that homeopathy has legitimate medical uses. We’ve seen this worldwide with homeopaths descending on Haiti or treating HIV in Africa, illustrating that proponents lack any insight into the lack of objective effects. More recently, the government of Madhya Pradesh, a state in India, announced a plan to use homeopathy to prevent malaria outbreaks. When homeopathy is used as a substitute for real medical treatments, the risk of harms are real, not theoretical. So I was concerned to to see the following in the Calgary Herald:

A Calgary business that aims to bring traditional homeopathic remedies to the mainstream public has received Health Canada approval for its first locally developed product. Mozi-Q is a natural mosquito repellent created by Calgary-based Xerion Dispensary. The product, made from a plant-derived substance called staphysagria, is taken orally and is advertised not only as a bug repellent, but as a product that will also lessen the stinging and itching associated with insect bites.

which also noted

All natural health products — including homeopathic remedies — sold in Canada are subject to the Natural Health Products Regulations, which came into force on Jan. 1, 2004. Only after Health Canada has assessed a product and decided it is safe, effective and of high quality, will a product be approved.

Effective. There it is. Yes, homeopathic insect repellent, approved by Health Canada with licence number 80031902, with the following “Recommended Use or Purpose”:

Homeopathic rememdy [sic] used for reducing the severity and frequency of insect bites.

And what’s in this product? Like most homeopathy, the labeling obscures the actual lack of ingredients. I converted the homeopathic labeling to English, and looked for evidence to support any of the ingredients – diluted or otherwise.

  • “cedron 4C:” This is Simaruba Ferroginea, commonly called Rattlesnake Bean in a 10−8 dilution (i.e., 0.000001%) — This product is related to the pinto bean. It is likely nontoxic, especially at this dilution.
  • “grindelia 6C”: Grindelia Robusta or Gumweed in a 10−12 dilution (i.e., 0.0000000001%) — This ingredient is considered “Possibly Safe” at non-homeopathic doses by the Natural Medicines Comprehensive Database
  • “ledum palustre 3X” : Marsh Tea in a 10−3 dilution (i.e., 0.1%) — This ingredient is considered “Likely Unsafe” at non-homeopathic doses by the Natural Medicines Comprehensive Database, causing kidney and urinary tract damage as well as central nervous system excitation.
  • “staphysagria 4X”: Delphinium staphisagria or Stavesacre in 10−4 dilution (i.e., 0.01%) — This ingredient is considered “Likely Unsafe” at non-homeopathic doses by the Natural Medicines Comprehensive Database, as it is poisonous.
  • “urtica urens 6X” : Stinging nettle in a 10−6 dilution (i.e., 0.0001%) — This ingredient is considered “Possibly Safe” at non-homeopathic doses by the Natural Medicines Comprehensive Database.

Interestingly, some of the ingredients aren’t diluted past the “12C” level, the point at which Avogadro’s constant establishes that there isn’t likely to be a single molecule of the original ingredient. The 3X dilution of Marsh Tea is only a 1:1000 dilution. Should we be concerned about toxicity? The manufacturing process, which involves dilution of a “mother tincture” of the initial product, means that the final dilute solution will only contain trace amounts of ledum. That final dilution is then sprayed on tiny sugar/lactose pills, so the final product isn’t likely to have a detectable trace of the original plant.

Does it work? Not surprisingly there is no published evidence suggesting that any component of Mozi-Q, either alone or in combination, have any effect on either reducing the frequency of insect bites” or “reducing the severity of insect bites”. The manufacturer states the following:

Has it been studied?
In the ’60s a homeopath by the name of HR. Trexler studied Staphysagria for its effectiveness at preventing mosquito bites. In a study of 421 subjects over a 4 year period, he found this remedy to be 90% effective.

Tried and True!
We have tested this remedy in our clinic over four mosquito seasons and found the response from the public confirmatory of Trexler’s findings.

And that’s the sum total of the evidence — which appeared to be adequate for Health Canada, who granted the “safe and effective” imprimatur of legitimacy. A published report from Trexler does date back to 1965, and it’s not available. There are no other published reports with the product. I did find Trexler’s US patent registration from 1956 claiming that staphsagria is an effective insect repellent. No evidence of a formal evaluation is described. A patent, of course, doesn’t establish efficacy. Given the totality of evidence, has failed to show that homeopathy has any meaningful clinical effects, I am skeptical that a homeopath identified an effective homeopathic oral insect repellent in 1956, and subjected it to a rigorous evaluation in the 1960’s. In any case, it would be easy to prove if it does work – it could be evaluated like every other insect repellent on the market.

How Real Insect Repellents work

For many of us, insect bites are an occasional annoyance that we can largely avoid. Yet insects can transmit over 100 diseases, including malaria, West Nile virus, yellow fever, Dengue fever, Lyme disease and even plague. Malaria alone kills 1.2 million people, mainly African children, annually. And now that we have West Nile and Lyme disease in Canada, there is a bigger impetus to minimize bites. Given the importance of repelling insects effectively, validated methods have been created to test new products.

While it’s not definitively established what attracts insects to bite, carbon dioxide and lactic acid seem to be important factors. In light of this, it’s not surprising that no oral product has ever been demonstrated to effectively work as an insect repellent. In order for an oral product to effectively repel insects, we’d have to consume enough that it would be absorbed and somehow secreted to the extent that it would repel insects – preferably without killing us, first. What does work, beyond physical barriers, are chemical products that we apply to our skin. The most common ingredient in repellents is N, N- diethyl-3-methylbenzamide, more commonly known as DEET, although there are several other chemicals that have been approved for use in consumer products.

How do you know if an insect repellent works? You offer your forearm up as a meal. Consumer Reports illustrates the testing nicely. The US Environmental Protection Agency specifies testing requirements in detail. Its approval outlines the duration of effectiveness as well as detailed descriptions of the efficacy and safety evaluations. In Canada, similar regulation rests with the Pest Management Regulatory Agency. When I asked the PMRA by email how a homeopathic remedy could be possibly be approved as an insect repellent, they replied with the following:

Please be advised that, according to the Pest Control Products Regulations (PCPR), pest control products that are used for the control of arthropods on or in humans or animals can be exempted from the Pest Control Products Act (PCPA), and made subject to the Food and Drugs Act (FDA), if the control product is to be administered directly and not by topical application. If the action of the product is not due to the simple presence of the active ingredient on the skin (the intent of topical application under the PCPA) but rather that the active ingredient has to be absorbed first before it can exert its effect, this is not considered to be a topical mode of action. This would be the case for mosquito repellent patch products. Even though the patch is to be applied to the surface of the skin, the PMRA does not register any pesticide that’s to be taken orally. Based on this systemic mode of action, as per a previous agreement between PMRA and Health Products and Food Branch (HPFB), the type of product you describe in your email would fall under the jurisdiction of HPFB.

Is there a facepalm emoticon? There is no “systemic mode of action” that has been demonstrated for homeopathy. There is no evidence that any oral products are effective as insect repellents. In the United States, a product like Mozi-Q which lacks published evidence of efficacy would not likely be permitted, (homeopathy or not) as there is a federal regulation on oral insect repellents in place, which notes:

Labeling claims for OTC orally administered insect repellent drug products are either false, misleading, or unsupported by scientific data.

Any OTC drug product that is labeled, represented, or promoted for oral use as an insect repellent is regarded as a new drug within the meaning of section 201(p) of the Federal Food, Drug and Cosmetic Act for which an approved new drug application under section 505 of the act and part 314 of this chapter is required for marketing. In the absence of an approved new drug application, such product is also misbranded under section 502 of the act.

Clinical investigations designed to obtain evidence that any drug product labeled, represented, or promoted OTC for oral use as an insect repellent is safe and effective for the purpose intended must comply with the requirements and procedures governing the use of investigational new drugs set forth in part 312 of this chapter.

Yet these products are being deliberately exempted from testing in Canada, and Health Canada is approving them in the absence of any published evidence to demonstrate they work.


When Health Canada removes scientific barriers to product approvals, we should not be surprised by what emerges. Homeopathic insect repellent that has been deemed “safe and effective” provides yet another example of the consequence of regulating homeopathy. Consumers who rely on regulators to test and approve products don’t care how a product is licensed – they want assurance that it works. Because while insect bites can be a nuisance, they can also be deadly. Who will be responsible if a consumer contracts a insect-borne disease if they use homeopathy instead of effective insect repellents: The manufacturer, or the regulator? In the absence of effective regulation of natural health products, pharmacists need to make their own decisions about which products should be sold in pharmacies.  The science in this case is very clear: The only demonstrably effective insect repellents are topical products and physical barriers – not homeopathy.

Photo from flickr user LOLO FROM TAHITI used under a CC licence.

5 thoughts on “When homeopathy is approved as an insect repellent, there’s a serious regulatory problem

  1. While I know that homeopathy is useless quack medicine, I would agree with Canada’s regulating of contents. Homeopathy in the U. S. can literally contain anything. The FDA doesn’t bother checking to see if the products contain what they say (I know, water) but they also would not know if the products are safe. Take for instance the Zicam debacle where it contained toxic levels of zinc.

  2. i just bought mozi-q today directly from Xerion homeopathie. ***it did NOT work*** the instructions (and the lady at the store who sold it to me) told me to take it 30 minutes before i went outside. she said to chew the pill a tiny little bit and then place it under my tongue so it can be absorbed sublingually, so i let it fully dissolve. it says it will work for 3-5 hours. i took it at 830pm i went outside at 10pm braved the outdoors in my backyard of urban suburban calgary, and i got 11 big mosquito welts in 15 min … and then ran inside frantically searching for my afterbite

    so $26.24 for 60 tabs… i should have wasted that money at stampede instead, so now i’m going back to my citronella spray with essential oils of eucalyptus & tea tree as that at least worked for me for the most part

  3. Any reasonably astute reader will pick up the crimson flags in this article, and be compelled to question them.

    1) Does the photo show mosquito bites on someone who took the product being derided here? I do not believe so, since I followed the copyright info to the photo’s contributor and learned the photo is simply labeled as “mosquito bites on a child thigh.” That’s a red herring at best, and a blatant misrepresentation in light of the fact that the writer purports to be a professional pharmacist. He should know better.

    2)The writer describes homeopathy as an “elaborate placebo system.” How does the writer know this?
    By his own description, the ingredients are so diluted as to be ineffective, then in the breakdown, none of the ingredients are labeled as dangerous, or poisonous.
    The writer offers no “proof” that the product, or homeopathy in general, does *not* work. He simply cites that no scientific studies have proved it. So he wants to use a lack of information to prove a negative.
    If the writer wished to be even remotely credible, he might have tried the product for himself, since by his own description, it is entirely inert, which suggests that safety is not a concern.
    If he found it did not work, his rant might gain a little traction. After all,
    3)Much more could be said about various points the writer makes, but the clincher comes under the heading Conclusion.
    The writer asks, “Who will be responsible if a consumer contracts a insect-borne disease if they use homeopathy instead of effective insect repellents: The manufacturer, or the regulator?”
    The implication of that question is that if I use an “approved” insect repellent, then contract West Nile, or Lyme, either the manufacturer or the regulator will take responsibility. Please tell me where to sign up for that deal! Because from where I stand, it looks too good to be true.
    We all know that we ourselves, no exceptions, have to live with the diseases we contract. No manufacturer or regulator is ever going to pick up the tab, or even take pity on us. But we can be certain of this:

    My conclusion: this appears to be the writing of a Big-Business Shill, someone tasked with distracting people from harmless solutions that many have found to be effective, and direct them instead to products that enhance the sponsor’s bottom line, and may or may not be as effective as the target of the attack.

    What do I know about Mozi-Q, you ask? Precious little, but after reading this article, I am going to try it out for myself.
    I already know this: Some of the “approved” insect repellents have failed me absolutely. Maybe I’d better get checked for West Nile.

    Finally, I did a search to learn a bit about DEET, the chemical cited as the most common insect repellent ingredient.
    Wikipedia offers this, under Effects on Health:

    *…(EPA) reported 14 to 46 cases of potential DEET-associated seizures, including 4 deaths.
    * “Everglades National Park employees having extensive DEET exposure were more likely to have insomnia, mood disturbances and impaired cognitive function than were lesser exposed co-workers”.[16]
    *DEET can act as an irritant;[4] in rare cases, it may cause severe epidermal reactions.[14]

    See how, with a few pasted phrases from Wikipedia, I can make you wonder about the safety of DEET?

    • I had a good laugh at your comment, however I’m wondering: why are you concluding that “the writer” is a big-business shill promoting “products that enhance the sponsor’s bottom line”, when I don’t see another product mentioned anywhere? And how would you respond to the claim that Mozi-Q themselves are big-business shills by selling sugar pills for 0.50$ a pill?

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