To effectively treat head lice, you need to apply the right amount of shampoo. The amount needed will depend on the length of your hair. If you have very short hair, you may need more shampoo for the second application. To determine the amount you will need, follow these guidelines. One ounce of shampoo per application is sufficient for short hair, and two ounces of shampoo for medium-length hair. These amounts are approximate and should be enough to treat one adult or child.
The most common type of lice shampoo contains permethrin, a synthetic version of the chemical compound pyrethrin. This substance is toxic to lice, but it is not toxic to humans. Another type of head lice shampoo is ivermectin, which is available over-the-counter and requires no prescription. These products can be applied to dry hair and rinsed out within ten minutes. However, they may cause eye irritation, dandruff, and burning at the application site.
The CDC recommends that you consult with a healthcare provider if you suspect you have lice. Although there are several treatments available, most of them fail to eliminate the disease completely. You should also consider visiting a health care professional if you’re concerned your child might have a lice infestation. A licensed healthcare provider will be able to prescribe a more effective prescription lice shampoo.