By Cynthia Bailey MD. This page was updated on Thu, Nov 07, 2019
What is benzoyl peroxide and how to use it for acne?
Benzoyl peroxide is a synthesized peroxide topical medicine used to treat acne. Also known as BPO, it is available in both prescription and non-prescription cleansers, gels and creams made to 2.5, 5 and 10% concentrations. Benzoyl peroxide is such a well-regarded medicine that it is on the World Health Organization’s List of Essential Medicines.
How to treat acne with benzoyl peroxide?
Benzoyl peroxide reduces the number and severity of acne lesions in 2 main ways:
- Benzoyl peroxide is bactericidal.
Meaning it kills the acne causing bacteria called C. acnes (formerly called P. acnes). Unlike antibiotics, this bacteria has not developed resistance to benzoyl peroxide like it has to all antibiotics used to treat acne. The 2.5% concentration is as effective as higher concentrations in treating acne. It is also less irritating to sensitive skin. Find 2.5% benzoyl peroxide in my 2.5% Benzoyl Peroxide Acne Treatment Cream.
- It acts as a keratolytic.
Meaning it clears out blackheads and keratin blockages in pores.
Benzoyl peroxide may also reduce inflammation and redness from acne lesions.
Benzoyl peroxide works quickly to treat acne, and you will start to see results in under a week. It helps blackheads, whiteheads and red acne pimples.
How do you use benzoyl peroxide to treat acne?
- Benzoyl peroxide is best applied in a thin layer to acne prone skin twice a day.
Ideally you want to treat the entire acne prone area, because benzoyl peroxide helps to reduce new acne lesions. Many people chose to use stronger concentrations of benzoyl peroxide cream or gel as a spot treatment for pimples too.
- Benzoyl peroxide can be combined with salicylic acid, glycolic acid, sulfur and topical antibiotics.
It can also be combined with adapalene (a synthetic retinoid). Other retinoids, such as retinol and tretinoin are deactivated by benzoyl peroxide.
Benzoyl peroxide side effects?
Benzoyl peroxide can cause skin irritation, redness, peeling and photosensitivity.
This risk is worse with higher strengths, making 2.5% the logical starting concentration. If irritation develops, the skin usually adjusts in several weeks, though some people develop stinging, itching and swelling and can’t tolerate benzoyl peroxide. Benzoyl peroxide can make the treated skin more sun sensitive too. Wearing sunscreen, using a moisturizer, starting on the lowest strength, and avoiding other harsh cleansers and products may help skin better tolerate benzoyl peroxide.
Benzoyl peroxide will bleach fabric!
Benzoyl peroxide vs. salicylic acid; Can you use them together to treat acne?
Salicylic acid and benzoyl peroxide are the two most well-known and effective non-prescription acne fighters. They both work wonders for acne prone skin.
Both help remove dead cells clogging your pores.
Benzoyl peroxide also kills bacteria.
Salicylic acid penetrates better into oily pores.
Together, these super power acne fighters work better than they do alone. You can use them both twice a day. One can be used as a cleanser, as in my Foaming Acne Treatment Cleanser, followed by a cream, as in my Benzoyl Peroxide Acne Treatment Cream 2.5%. Or, you can use one as a pad that evaporates quickly, as in my Salicylic Acid and Glycolic Acid Acne Treatment Pads, followed by the Benzoyl Peroxide Cream.
Benzoyl peroxide cleansers are the best way to treat back and chest acne.
Applying creams is difficult on the large expanse of chest and back skin. Instead, use medicated cleansers. My Foaming Benzoyl Peroxide 10% Cleanser can be applied with a Salux Shower Cloth. After rinsing-off the cleanser's lather from skin in the shower, medicated benzoyl peroxide medicine will remain behind to treat acne (and bleach fabric so wear white). You can alternate this with Foaming Zinc Cleanser to treat the common type of back and chest acne called Pityrosporum folliculitis. All the products come in my Back Acne Kit.
Can you use benzoyl peroxide if you are pregnant?
No. It is unclear if benzoyl peroxide is safe to use during pregnancy, meaning use should be avoided.