Overview

Products to treat lice range from over-the-counter (OTC) treatments, to prescription treatments, to alternative treatments. Your choice may depend on one of many factors. For example, if your lice are resistant to OTC treatment, you may need a prescription product. Alternatively, you may want a more natural treatment. Knowing a little information about the available lice treatments can go a long way in helping you to make an informed choice.

The typical first-line treatment for lice is an OTC shampoo, such as Rid or Nix. Both of these products contain chemicals from a class of chemical compounds called pyrethrins. Chemicals in this class occur naturally, but they can also be man-made. These chemicals interfere with the lice’s nervous systems to kill them. These and similar OTC products may also include gels and cream rinses that help you comb the lice out of your hair after treatment.

Rid and Nix are available in most pharmacies and cost about the same.

Rid

You can use Rid for people who are 2 years of age and older. To treat lice, apply the Rid shampoo to dry hair and leave on for 10 minutes. After that time, add some warm water and rub your head to form a lather. Then rinse your hair with water. You may use a fine-toothed comb to remove lice and eggs from the hair after treatment. In seven to 10 days, you need to repeat this process to kill any lice that have hatched since the first treatment.

The active ingredient in Rid is an insecticide called pyrethrum extract. Rid also contains an ingredient called piperonyl butoxide. This helps the pyrethrum extract work better because it prevents lice from breaking the pyrethrum extract down. The Environmental Protection Agency (EPA) classifies piperonyl butoxide as a possible human cancer-causing agent. However, the strength of this chemical in Rid is only 4 percent, which is considered safe for limited periods of exposure.

Nix

Nix can be used for people who are 2 months and older. To treat lice, apply Nix to freshly shampooed hair, but be sure not to use conditioner. Use enough Nix to fully cover all your hair and your scalp. Leave it on for 10 minutes, then rinse it out with warm water. You can also use a fine-tooth comb to remove lice and eggs from the hair afterwards.

Nix contains permethrin, which is in the same chemical class as pyrethrum extract. Permethrin is supposed to leave a residue on the hair which may help to kill lice that hatch after the first treatment. Some additives to the shampoo may limit this residue effect. With either Nix or Rid, it is important to check for new live lice over the 7 to 10 days after treatment and retreat if any new live lice are found. Unlike Rid, Nix does not contain piperonyl butoxide.

If OTC products don’t treat your lice or if infestations come back repeatedly, consider asking your doctor if you are treating the infestation properly or if prescription medications may help. Prescription treatments include: malathion (Ovide), lindane (Kwell), benzyl alcohol (Ulesfia), ivermectin (Sklice), and spinosad (Natroba). Your pharmacy may not have your specific prescription product, so make sure to call in advance. If your pharmacy doesn’t have it, they should be able to order it for you.

The costs among these products vary, but they are all much more expensive than OTC treatments. Lindane is typically the least expensive, and ivermectin is the most expensive.

Insurance coverage of these treatments also varies. Some companies may require a prior authorization from your doctor. This is to make sure that you have tried OTC therapies first or that the lice in your case are resistant to OTC treatment.

Malathion (Ovide)

Malathion is available as a lotion. It kills lice by affecting a chemical in their nervous system.

To treat lice, apply malathion to dry hair, using enough to make it wet. Then, without covering your hair, allow the hair to dry naturally. Malathion is flammable, so make sure you don’t use a hair dryer or any source of heat while the product is on your hair. After eight to 12 hours, wash the hair with regular shampoo and rinse it with water. Use a fine-tooth comb to remove dead lice and eggs. One treatment should be enough to get rid of the infestation. If it isn’t, you can repeat the treatment in seven to nine days.

Malathion is only for use in people who are older than 6 years old. Women who are pregnant or breastfeeding shouldn’t use it unless directed by their doctor.

Side effects of malathion can include scalp and skin irritation. Inhaling vapors of malathion may cause wheezing or shortness of breath in some people, particularly those with asthma.

Lindane (Kwell)

Lindane comes in a shampoo. It kills the lice by making their nervous systems overact.

Wait at least one hour after washing hair, bathing, or showering. Do not use conditioner before using this treatment. To treat lice, lindane should be applied to clean, dry hair. Use only enough lindane shampoo to coat the hair lightly. Leave it on for four minutes. After four minutes, add water and work into a lather, then rinse. Afterwards, you can use a nit comb to remove the dead lice and eggs.

There is no specific age limit for lindane, but people who weigh less than 110 pounds shouldn’t use it. Women who are pregnant or breastfeeding and people who have HIV infection also shouldn’t use this product.

Among the possible side effects of this drug are skin rashes and seizures. However, these effects are uncommon.

Benzyl alcohol (Ulesfia)

This is a new product that comes in a lotion and essentially suffocates the lice.

Benzyl alcohol can be used in people who are older than 6 months. To treat lice, apply the lotion to dry hair. Use enough to saturate your scalp and hair. Leave it on for 10 minutes and then rinse it out with water. Repeat this process after seven days.

Ivermectin (Sklice)

Ivermectin is another recently approved prescription medication. Ivermectin is a substance that is derived from bacteria. The treatment comes in a lotion. It kills lice by disrupting their nervous systems.

To treat lice, apply the lotion to dry hair. Leave it in for 10 minutes, and then wash it out with only water. You only have to apply ivermectin once.

Ivermectin can be used for people who are 6 months and older. Women who are pregnant or breastfeeding shouldn’t use this product unless directed by their doctor.

Common side effects of ivermectin include:

  • eye redness or soreness
  • eye irritation
  • dandruff
  • dry skin
  • burning sensation of the skin

Spinosad (Natroba)

Spinosad comes in a lotion. It targets the nervous system of lice. This leads to increased activity that can paralyze and kill the lice.

People who are 6 months and older can use spinosad. You apply spinosad to dry hair, working from the scalp toward the ends of the hair. Leave it on for 10 minutes, then rinse it out with warm water. You will likely need just one treatment. However, if you still have lice seven days after treatment, you can use spinosad a second time.

This treatment can cause skin redness, but this effect is uncommon.

Some lice treatments on the market contain more natural ingredients. Chick-Chack (also known as HairClean 1-2-3) contains coconut oil, anise oil, and ylang ylang oil. Products containing tea tree oil and lavender oil are also available. Other products contain the essential oils of neem, eucalyptus, cloves, and peppermint. Research has indicated some degree of success among all of these products in treating lice, but it is mostly anecdotal. Given that these products are not regulated by the FDA and may have unanticipated side effects, they should not be used on infants or young children.

Typically, the first line of treatment for lice is an OTC product like Rid or Nix. However, if you’re looking for a more natural product or if OTC treatments haven’t worked, talk to your doctor about a lice treatment that is right for you.