Avoid getting this medication in your mouth or eyes. If it does get into any of these areas, rinse with water. Do not use benzoyl peroxide topical on sunburned, windburned, dry, chapped, irritated, or broken skin. Also avoid using benzoyl peroxide topical on wounds or on areas of eczema. Wait until these conditions have healed before using this medication.

Avoid using skin products that can cause irritation, such as harsh soaps, shampoos, or skin cleansers, hair coloring or permanent chemicals, hair removers or waxes, or skin products with alcohol, spices, astringents, or lime. Do not use other medicated skin products unless your doctor has told you to.

Do not use benzoyl peroxide topical while you are also using tretinoin (Altinac, Avita, Renova, Retin-A, Tretin-X). Using these medications together could cause severe skin irritation. FDA pregnancy category C. It is not known whether benzoyl peroxide topical will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication. It is not known whether benzoyl peroxide passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

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

Do NOT use Benzac if you are allergic to any ingredient in Benzac.

All medicines may cause side effects, but many people have no, or minor side effects.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using benzoyl peroxide and call your doctor at once if you have severe stinging or burning of your skin.

Less serious side effects 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.