This depends on whether you use Elimax® Lotion or Elimax® Shampoo. When using Elimax® Lotion you will need to wash your hair with an ordinary shampoo after the treatment. Elimax® Lotion kills lice and nits and keeps infestations at bay, but it doesn’t wash your hair. With Elimax® Shampoo your hair is treated and washed in a single step.