Take control of lice infestations with this Maximum Strength Lice Killing Shampoo. Formulated with Pyrethrum Extract (a natural insecticide from chrysanthemum flowers) and Piperonyl Butoxide, this shampoo works by effectively paralyzing and killing lice on contact. It is designed for use on adults and children over 2 years of age. The formula is tough on lice but gentle on the scalp, leaving no sticky residue behind. To ensure complete success, this treatment usually requires a second application 7 to 10 days after the first to kill any newly hatched lice. Most kits include a professional-grade nit comb to help remove dead lice and eggs (nits) from the hair shaft.