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Malathion (On the skin)

Malathion (mal-a-THYE-on)

Treats head lice infection.

Brand Name(s):


There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You should not use this medicine if you have had an allergic reaction to malathion. You should not use this medicine on children younger than 1 year of age.

How to Use This Medicine:


  • Use on scalp hair only. Keep your eyes tightly closed while you apply this medicine. Wash your scalp right away if skin irritation occurs.
  • To use:
    • Apply the lotion to dry hair and rub it in until your hair and scalp are thoroughly moistened.
    • Wash your hands with soap and water before and after you use this medicine.
    • Leave your hair uncovered and allow it to dry naturally. Do not use a hair dryer.
    • After 8 to 12 hours, wash your hair with a non-medicated shampoo. Rinse thoroughly.
    • After rinsing, use a fine-toothed (nit) comb to remove the dead lice and eggs.
    • If lice are still present after 7 to 9 days, use a second application of malathion lotion.
  • This medicine is flammable. Keep the lotion and wet hair away from open flames. Do not use electric heat sources such as hair dryers and curlers while your hair is wet. Do not smoke while you apply this medicine or while your hair is wet.

If a dose is missed:

  • Apply a dose as soon as you can. If it is almost time for your next dose, wait until then and apply a regular dose. Do not apply extra medicine to make up for a missed dose.

How to Store and Dispose of This Medicine:

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep the medicine away from heat or open flame.
  • Ask your pharmacist or doctor how to dispose of the medicine container and any leftover or expired medicine.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Do not put cosmetics or skin care products on the treated skin.

Warnings While Using This Medicine:

  • Make sure your doctor knows if you are pregnant or breastfeeding.
  • Be careful not get any of this medicine in your eyes. If you do, flush your eyes with water for at least 10 minutes. Check with your doctor if your eyes become irritated or your vision changes.
  • Call a doctor or poison control center right away if you accidentally swallow this medicine.
  • Wash your scalp and hair immediately if skin irritation occurs. If the irritation goes away after you wash your hair, you may apply the medicine again. If the irritation happens again, check with your doctor.
  • Call your doctor right away if you have pain or blistering after you use this medicine.
  • Do not use this medicine on your child unless your doctor says it is okay.
  • Do not use this medicine to treat a skin problem your doctor has not examined.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Blistering and peeling of the skin
  • Pain, reddening, or swelling of the skin

If you notice these less serious side effects, talk with your doctor:

  • Burning, dry, or itching eyes or changes in your vision
  • Stinging sensation or irritation on your scalp or skin

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 5/1/2020

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