Lice prevention shampoo is the most important of all lice removal products on the market. Many products will advertise that they have a high kill rate. That refers to the amount of lice they kill on contact. Anything less then 100% kill rate is worthless. Any louse that survived the initial shampoo will reproduce and in no time you will be fully infested again. The licenders enzyme lice shampoo is all natural and has a 100% kill rate when you follow directions.