What Is Benzoyl Peroxide?


Benzoyl peroxide is the workhorse of acne product ingredients. This medication is found in various concentrations in over-the-counter topicals, and is often incorporated into prescription topical medications. Like most topical medications that fend off acne lesions, benzoyl peroxide can irritate the skin, especially when used with skincare products that are harsh and abrasive. Side-effects are reduced by using the medication appropriately and treating acne-prone skin gently.

How It Works

Benzoyl peroxide is the most effective acne-fighting ingredient in nonprescription acne treatments, says the Mayo Clinic. It works by reducing the population of P. acnes bacteria on the skin that cause inflammation and by sloughing off dead skin cells so that pores won’t clog. Benzoyl peroxide is sold in concentrations that range from 2.5 to 10 percent. The most common side-effect of benzoyl peroxide is dry skin, says the American Academy of Dermatology (AAD), but it can also cause redness, scaling, burning and stinging. Side-effects may be worse for people with sensitive skin.

Benzoyl Peroxide Preparations

Benzoyl peroxide is available in a variety of forms, says the Mayo Clinic. These may include soap, lotion, gel, cream, liquid, foam and pads. Although a common active ingredient in numerous over-the-counter acne products, some preparations require a doctor’s prescription. The AAD indicates that many prescription topical antibiotics, such as erythromycin and clindamycin, also include benzoyl peroxide, as this combination decreases the chances that a patient will develop a resistance to the antibiotic.

Proper Use

Those using benzoyl peroxide as a leave-on acne treatment should wash the skin first, using a mild cleanser, and blot dry gently. The AAD advises waiting 5 to 15 minutes before applying any acne treatment; when the skin is freshly-washed, it absorbs more of the medication, increasing the risk of side-effects. More isn’t necessarily better: Mayo Clinic experts cautions against using more benzoyl peroxide than recommended, as this can also increase side-effects. The medication should not be applied near the eyes or lips, inside the nose or on the neck. Benzoyl peroxide should not be applied on wind-chapped or sunburned skin or directly to open wounds except as instructed by a doctor.

Avoiding Skin Irritation

Benzoyl peroxide is a poor mix with skincare and cosmetic products that contain lime, spices, alcohol or peeling agents such as resorcinol, salicylic acid, sulfur and tretinoin, as using them concomitantly can cause skin irritation. Layering other topical medications on top of benzoyl peroxide an hour before or after application is not advised; depilatory creams and chemical hair treatments like permanents can also exacerbate side-effects, as can any skincare product that’s too harsh, abrasive or drying. If a doctor prescribes another prescription topical, such as a topical tretinoin, in addition to benzoyl peroxide, says the Mayo Clinic, one is generally used during the day and the other at night.


Benzoyl peroxide has a lightening effect, cautions the AAD. Towels, bedding, clothing and even hair can be bleached. Those using this medication on the back or chest are advised to wear old clothing, as it may get ruined.