To the mom who is using two kinds of shampoos for the "prevention" of lice. These products are toxic, and should not be used prophylactally. They are to be used only if lice or (most likely) nits are found. Using these products will not prevent someone from getting lice. Simply by using personal combs and brushes, using the appropriate product on the actual cases, and lastly but most importantly, "nit-picking" after using the shampoo will the problem disappear. Good Luck. The medicated shampoos are not recommended while pregnant or nursing, and they should only be used whenever evidence of lice appears, not as a preventative. Claire Goldberg, RN BScN IBCLC Edmonton Alberta Canada