What Is Permethrin? Uses, Dosage, and What You Need to Know in 2026

Permethrin is a synthetic medication used to treat parasitic skin infestations. It's the first-line treatment recommended by the CDC, the American Academy of Pediatrics (AAP), and the American Academy of Dermatology for both scabies and head lice. If you or a family member has been diagnosed with either condition, permethrin is likely what your doctor will prescribe.

What Is Permethrin Used For?

Permethrin is FDA-approved for two indications:

Scabies (Sarcoptes scabiei) — A skin infestation caused by tiny mites that burrow into the outer layers of skin. Causes intense itching (especially at night) and a characteristic rash. Treated with permethrin 5% cream.

Head lice (Pediculosis capitis) — An infestation of the scalp by tiny insects called lice. Causes scalp itching and visible nits (eggs) attached to hair shafts. Treated with permethrin 1% lotion.

Permethrin is also used off-label for pubic lice (crabs) and as a preventive spray on outdoor clothing and gear to repel insects, including ticks and mosquitoes.

Permethrin Brand Names

Nix — OTC 1% lotion for head lice

Elimite — Brand name for 5% cream (brand discontinued; generic available Rx only)

Acticin — Another brand for 5% cream

Permethrin Dosage and How to Use It Correctly

For Scabies (Permethrin 5% Cream)

Wash and dry your skin before application.

Apply the 5% cream from the neck down to the soles of the feet. Massage into all skin, paying special attention to creases — between fingers and toes, wrists, elbows, underarms, groin, genitalia, and buttocks.

For infants and geriatric patients, also apply to the scalp, temples, and forehead. (Scabies rarely infests the scalp of healthy adults.)

Leave the cream on for 8 to 14 hours (usually overnight).

Wash off thoroughly by bathing or showering.

One application is generally curative. If live mites are still present after 14 days, a second application or alternative therapy may be needed.

A standard adult treatment uses approximately 30 grams (one tube).

For Head Lice (Permethrin 1% Lotion)

Wash hair with regular shampoo (not a conditioning shampoo — conditioner reduces effectiveness). Rinse and towel-dry.

Apply the lotion thoroughly to the hair and scalp, especially behind the ears and at the nape of the neck.

Leave the lotion on for 10 minutes.

Rinse with warm water. Use the fine-tooth nit comb provided to remove any remaining nits.

If live lice are still present 7-9 days later, a second treatment may be needed.

Important Steps After Treatment

Treating with permethrin alone is not enough. Environmental decontamination is essential to prevent reinfection:

Wash all clothing, bedding, and towels used in the 3 days before treatment in hot water (above 122°F / 50°C) and dry on high heat.

Place non-washable items in a sealed plastic bag for at least 72 hours.

Treat all household members and close contacts at the same time, even if they have no symptoms.

Is Permethrin Available Over the Counter?

The 1% lotion (Nix) for head lice is available over the counter without a prescription at most pharmacies and grocery stores. The 5% cream for scabies requires a prescription from a doctor, nurse practitioner, or physician assistant. Telehealth providers can issue this prescription quickly for most patients.

When to Seek Follow-Up Care

Return for follow-up if live mites or lice are still visible 14 days after treatment. Itching after treatment can persist for up to 4 weeks and is usually not a sign of failure. Read more about permethrin side effects and what to expect. If you need help finding permethrin at a pharmacy near you, medfinder can help.