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Generic name: benzyl alcohol topical [ BEN-zil-AL-ka-hol-TOP-i-kal ]
Brand names: zilactin, zilactin-L
Drug class: Topical anti-infectives

Medically reviewed by on Aug 7, 2023. Written by Cerner Multum.

What is zilactin?

The Ulesfia brand of benzyl alcohol topical is used to treat head lice in people between 6 months of age and 60 years old.

The Zilactin brand of zilactin is used to treat sores in or around the mouth, including cold sores, canker sores, or irritated gums. Zilactin is for use in adults and chlidren at least 2 years old.

zilactin may also be used for purposes not listed in this medication guide.

zilactin side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

If the medicine gets in your eyes or on your skin, rinse with water. Call your doctor at once if you have severe stinging, itching, or irritation of the eyes or skin after rinsing.

This medicine may cause serious side effects. Stop using this medicine and call your doctor at once if you have:

Common side effects of zilactin may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

Tell your doctor if you have ever had:

zilactin contains an ingredient that can cause serious side effects or death in very young or premature babies.

Tell your doctor if you are pregnant or breastfeeding.

You should not breastfeed while using Ulesfia.

How should I use zilactin?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Do not allow a young child to use zilactin without help from an adult.

Do not take Ulesfia by mouth. It is for use only on the hair and scalp. You may apply Zilactin to sores inside the mouth, but do not swallow the gel.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

Wash your hands with soap and water after applying this medicine.

Do not wet your hair or scalp before applying Ulesfia. Apply enough lotion to completely soak your scalp and hair and massage in thoroughly.

Leave the lotion on for 10 minutes, keeping your eyes closed and covered with a towel during this time. Then rinse out thoroughly with water. Use a fine-tooth nit comb to remove lice eggs from the hair, rinsing the comb often during use. Place removed nits into a sealed plastic bag and throw it into the trash to prevent re-infestation.

zilactin will not get rid of lice eggs so you must use a second application of this medicine 7 days after the first use.

Wash all clothing, hats, bed clothes, bed linens, and towels in hot water and dry in high heat. Dry-clean any non-washable clothing. Hair brushes, combs, and hair accessories should be soaked in hot water.

Apply Zilactin only to a cold sore or mouth sore, not to the surrounding skin or gum area.

Zilactin gel dries into a clear protective film. To remove this film, first apply another coat of the gel and then wipe the area with a moist gauze pad or tissue. Do not try and peel off the film.

Do not use Zilactin for longer than 7 days in a row. Stop using the medicine and call your doctor if your mouth sore does not improve after 7 days, if it gets worse, or if it clears up and then comes back in a few days.

Store at room temperature away from moisture and heat. Do not freeze.

Zilactin is flammable. Do not use near high heat or open flame. Do not smoke until the gel has completely dried on your skin.

What happens if I miss a dose?

Ask your doctor if you missed your second application of Ulesfia.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222 if anyone has accidentally swallowed this medication.

What should I avoid while using zilactin?

Avoid getting zilactin in your eyes.

Avoid getting Ulesfia in your eyes or mouth. It is for use only on the hair and scalp.

To prevent spreading lice, avoid head to head contact with others until your lice infection has cleared up. Avoid sharing hair brushes, combs, hair accessories, hats, scarves, and pillows. Lice infections are highly contagious.

What other drugs will affect zilactin?

Medicine used on the skin is not likely to be affected by other drugs you use. But many drugs can interact with each other. Tell each of your healthcare providers about all medicines you use, including prescription and over-the-counter medicines, vitamins, and herbal products.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.