The term "lice shampoo" is kind of a catch-all phrase representing all sorts of topical lice-treatment products. In reality, these products come in shampoos, rinses, gels, mousses, lotions, sprays, foams, ointments and oils.
Lice shampoos are sold online, over the counter at drugstores, and even at the pharmacy as a prescribed drug. They are used primarily as home lice treatments (as opposed to professional lice treatments), and have the same goal: kill as many lice and lice eggs as possible, in the fewest treatments as possible.
Regardless of the form the products actually take, understanding what ingredients they have in them, and how safe, fast and effective those products are, will help you make a better decision on what products to buy. It always pays to read the fine print.
Based on their ingredients, there are basically three types of lice shampoos: pesticide products, herbal products, and suffocation products.
Pesticide products use insecticides to poison the lice. Many parents have expressed concern about putting these chemicals on their kids' heads. At least the products are regulated by the FDA or other international regulatory agencies, so they are required to list certain potential risks on their product labels. Also, lice have been developing resistance (these are called super-lice) to many pesticide-based lice products lately, which means they aren't as effective as they once were.
Herbal lice remedies tout themselves as "chemical-free" and use essential oils instead of pesticides to repel or kill the lice. Although lice combs and dehydration products are chemical-free types of lice treatment, consumers usually think of these herbal remedies when they want natural lice treatments. Because most of these products are not regulated by the FDA, they aren't scrutinized as closely regarding product effectiveness (and potential risks).
Suffocation products use synthetic ingredients such as oils and silicone-based compounds that plug up (or paralyze) a louse's airways. Some of these products are used by professional nitpickers after a thorough comb-out as a back-up measure in case they missed any lice.
Although lice shampoos kill lice with varying degrees of effectiveness, they have a tough time killing the lice nits (eggs) in very high numbers. So if you treat head lice with these shampoos, you should plan on doing at least one follow-up treatment about a week to ten days later, to catch any lice that may have hatched from eggs unaffected by the initial treatment.
Other lice treatment options include lice combs (which can remove lice and eggs from the head rather than killing them) and the AirAllé™ device, which uses heated air to kill lice and 99.2 percent of lice eggs.