Lice Shampoo should not be left on your child's head longer then the directions recommend. As parents we want what's best for our child. We often forget that over usage can be dangerous. Read the ingredients of the head lice shampoo you are about to use. Can you pronounce all the words? Licenders all natural head lice shampoo is the safe way to go when you want to end a lice infestation. Just remember to follow directions. More is not necessarily better for your child. Always follow directions and resist the urge to over use. Licenders products let you get rid of lice naturally.