“These cleansers either use an enzyme that breaks down the glue that the lice use to hold onto your head (so when you comb, they come out easier),” Jessica Sammis, owner of Nit Nabbers in Charlotte, N.C, told us. “Or the formula incorporates a very oily liquid, like olive oil or coconut oil, which smothers live bugs and suffocates them.” Active ingredients can also include pyrethrins -- a naturally occurring insecticide from the chrysanthemum flower, or permethrin lotion -- a synthetic pyrethroid.
If over-the-counter shampoos don’t work, you can get a stronger prescription shampoo that contains either malathion lotion, an organophosphate chemical often used as the base for insecticides, or benzyl alcohol lotion, an aromatic alcohol. Both substances are FDA-approved, but kids under 6-years-old should steer clear of malathion.
Take note though, these shampoos only kill live lice, not unhatched eggs or nits (that’s why most recommend reapplying in seven to 10 days). Also, lice can get resistant to these pesticides, warns Sammis.
Your best line of treatment? Get a good lice treatment comb and meticulously comb and comb and comb every day until they are gone. These tools have several densely packed metal prongs that detach lice from stands.