Nit-Enz is an on-going head lice control system! Use Nit-Enz Organic Shampoo as a treatment to eradicate head lice, then continue using Nit-Enz Organic Shampoo twice a week like a normal shampoo, normal conditioner afterwards. Continued shampooing knocks out the eggs and lice before the life cycle can begin again! A repellent product should be used daily.