Benzoyl peroxide has an antibacterial effect. It also has a mild drying effect, which allows excess oils and dirt to be easily washed away from the skin.

Fostex Gel 10% (for the skin) is used to treat acne.

There are many brands and forms of benzoyl peroxide available. Not all brands are listed on this leaflet.

Fostex Gel 10% may also be used for purposes not listed in this medication guide.

Benzoyl peroxide can cause a rare but serious allergic reaction or severe skin irritation. Stop using this medicine and get emergency medical help if you have: hives, itching; difficult breathing, feeling light-headed; or swelling of your face, lips, tongue, or throat.

Fostex Gel 10% can cause a rare but serious allergic reaction or severe skin irritation. Before you start using this medicine, you may choose to apply a "test dose" to see if you have a reaction. Apply a very small amount of the medicine to 1 or 2 small acne areas every day for 3 days in a row. If there is no reaction, begin using the full prescribed amount on the 4th day.

Use exactly as directed on the label, or as prescribed by your doctor.

Do not take by mouth. Topical medicine is for use only on the skin. Do not use on open wounds or on sunburned, windburned, dry, or irritated skin. Also avoid using Fostex Gel 10% on wounds or on areas of eczema. Wait until these conditions have healed before using this medication.

Wash your hands before and after applying this medication.

Clean and pat dry the skin to be treated. Apply benzoyl peroxide in a thin layer and rub in gently.

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

You may need to shake the medicine just before each use.

Do not cover the treated skin area unless your doctor has told you to.

Benzoyl peroxide may bleach hair or fabrics. Avoid allowing this medication to come into contact with your hair or clothing.

It may take several weeks before your symptoms improve. Keep using the medication as directed and tell your doctor if your symptoms do not improve.

Store at room temperature away from moisture and heat.

You should not use benzoyl peroxide if you are allergic to it, or if you have:

• very sensitive skin.

Ask a doctor or pharmacist if Fostex Gel 10% is safe to use if you have any skin conditions or allergies.

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

Do not use this medicine on a child without medical advice.

Apply the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not apply two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Rinse with water if Fostex Gel 10% gets in your eyes or mouth.

Avoid using skin products that can cause irritation, such as harsh soaps, shampoos, hair coloring or permanent chemicals, hair removers or waxes, or skin products with alcohol, spices, astringents, or lime.

Avoid exposure to sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Fostex Gel 10% can cause a rare but serious allergic reaction or severe skin irritation. These reactions may occur just a few minutes after you apply the medicine, or within a day or longer afterward.

Stop using Fostex Gel 10% and get emergency medical help if you have signs of an allergic reaction: hives, itching; difficult breathing, feeling light-headed; swelling of your face, lips, tongue, or throat.

Stop using benzoyl peroxide and call your doctor at once if you have any of these side effects on the treated skin:

• severe itching or burning;

• severe stinging or redness;

• swelling; or

• peeling.

Common side effects of Fostex Gel 10% may include:

• mild stinging or burning;

• itching or tingly feeling;

• skin dryness, peeling, or flaking; or

• redness or other irritation.

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.

Applying benzoyl peroxide while you are also using tretinoin topical medicine may cause severe skin irritation. Brands that contain tretinoin include Avita, Renova, Retin-A, Tretin-X, and others.

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 health care providers about all medicines you use, including prescription and over-the-counter medicines, vitamins, and herbal products.