Lice Treatment Service » Head Lice Tips » Chemical Lice Treatments: Pick Your Poison

Chemical Lice Treatments: Pick Your Poison

bottle of purple liquid skull and crossbones poison on label.

Updated on June 25, 2020

By Lice Technicians, Chelsea Lonergan

Why put something that may be toxic onto the heads of your loved ones? There are safer and more effective treatments available!

Chemical lice treatments have been used (and abused) since World War II. The initial development of DDT led to its use in many facets of society, including dusting prisoners of war to help squelch the lice outbreaks. Ultimately, the rapid increase in lice resistance, as well as the infamous, severe health outcomes led to its demise.

Since DDT’s rise and fall, scientists have developed and tested chemical lice treatments extensively. Strikingly, many chemicals have drastically ramped up lice resistance—over 99.6% of U.S. lice are now classified as chemical-resistant “super lice”. And there are other reasons you may want to do some digging before coating your loved ones’ (or your) heads in the stuff.

1. Pyrethrins/Pyrethrum (Active ingredient in: A-200, Bio-Sentry, End-Lice, Licetrol, Pronto, RID)

Research has shown that these can lead to burns or rashes. Other research has been mixed. Convulsions can occur if large amounts are ingested by accident. There have been two recorded deaths of pyrethrin-linked asthma. There has also been research linking pyrethrins to dermatitis, and erosions of the cornea when exposed to the chemical (Proudfoot, 2005).

2. Permethrin (Active ingredient in: Nix, RID)

In clinical trial, when compared to soya oil-based shampoo, coconut, and anise spray, permethrin is less effective. Further, although it has long-been believed to be minimally low in toxicity to humans, there is increasing evidence that it may lead to  “neurotoxicity, immunotoxicity, cardiotoxicity, hepatotoxicity, reproductive, genotoxic, and haematotoxic effects, digestive system toxicity, and cytotoxicity” (Wang et al., 2016, p.86).

3. Lindane (Active ingredient in: G-well, Kwell)

Research has shown that these can also lead to burns or rashes, along with other safety concerns. Further, they’ve been banned in 52 countries and restricted in 33 due to serious health concerns (Haiken, 2014).

4. Malathion (Active ingredient in: Ovide Prioderm)

Some scientists have warned against using Malathion in very young children (under 6 months), and it has been linked to headache, dizziness, nausea, vomiting, and many other adverse side effects of over-exposure (Moore, Yedjou, & Tchounwou, 2010).

Given potential risks associated with chemical lice treatments, along with the growing resistance of head lice to these products, we recommend a natural, safe approach. Call LiceDoctors in Westfield and Noblesville and surrounding areas at 317-759-2699 . An experienced lice professional will make a house call to you and leave you healthy and lice free!


Haiken, M. (2014, Sep 8). Forget treating your kids’ head lice with chemicals: Here are toxic-free alternatives that really work. TakePart. Retrieved from:

Moore, P. D., Yedjou, C. G., & Tchounwou, P. B. (2010). Malathion‐induced oxidative stress, cytotoxicity, and genotoxicity in human liver carcinoma (HepG2) cells. Environmental toxicology25(3), 221-226.

Proudfoot, A. T. (2005). Poisoning due to pyrethrins. Toxicological Reviews24(2), 107-113.

Wang, X., Martínez, M. A., Dai, M., Chen, D., Ares, I., Romero, A., … & Anadón, A. (2016). Permethrin-induced oxidative stress and toxicity and metabolism. A review. Environmental Research149, 86-104.