There are over the counter medicines and prescription products on the market to treat head lice. Most lice treatment shampoo is applied to the head and left on for a period of time, and then rinsed off. Do not reapply natural lice shampoo There are over the counter medicines and prescription products on the market to treat head lice. Most lice treatment shampoo is applied to the head and left on for a period of time, and then rinsed off. Do not reapply natural lice shampoo