Is benzoyl peroxide safe? Side effects and allergy

Benzoyl peroxide is one of the most used acne medicines, and it has a long safety record. The American Academy of Dermatology (AAD) calls it "one of the most effective and commonly used acne treatments," and its 2024 acne guideline gives it a "strong" recommendation. Like any medicine, it has side effects. Most are mild and happen on the skin where you put it. A few are rare and serious. This guide sets out each one, what the FDA found when it tested products for benzene in 2025, and what the sources say about pregnancy, children and storage. For the ingredient as a whole, see the benzoyl peroxide guide.

Skinli gives general education. A doctor or pharmacist is the right person to diagnose and treat your skin.

The short answer

The FDA rule for store acne products, 21 CFR Part 333, says a store acne product that meets its conditions "is generally recognized as safe and effective." Benzoyl peroxide is on that rule's list at 2.5% to 10%. That status comes with conditions: the product must carry the FDA's warnings and directions, and you must follow them.

Risk	How common	What to do
Dryness, redness, peeling, burning	Common, mostly in the first weeks	Use it less often or at a lower strength
Bleached hair and fabric	Common if it touches them	Keep it off hair, towels and clothes
Sunburn	More likely while using it	Use sunscreen and limit sun
Serious allergic reaction	Rare	Stop and get emergency help
Benzene in the product	Low in FDA testing, higher with heat	Store it cool, replace it, discard old tubes

Common side effects

The FDA label lists them: "skin irritation may occur, characterized by redness, burning, itching, peeling, or possibly swelling." The NHS lists "hot, itchy or painful skin," redness and "dry or peeling skin" as common side effects, and says they "usually improve after a few days, or if you use the gel or gel wash less often."

Trials give a sense of how often. In a 2017 trial of 609 people in Japan, side effects of any kind occurred in 56.4% of people using 2.5% gel and 58.8% using 5% gel, all mild or moderate. Peeling skin was the most frequent, at 20.6% and 24.0%. Most side effects did not make people stop.

The label gives the remedy: "Irritation may be reduced by using the product less frequently or in a lower concentration." The directions say to start with one application a day and to "reduce application to once a day or every other day" if dryness or peeling bothers you. A moisturizer helps too, as the moisturizer guide explains. The label says to "stop use and ask a doctor if irritation becomes severe." The purging guide explains how to tell early irritation from acne that is getting worse.

Allergic reactions

In June 2014 the FDA warned that store acne products "can cause rare but serious and potentially life-threatening allergic reactions or severe irritation." It found 131 serious cases reported from 1969 through January 2013, for products with benzoyl peroxide or salicylic acid. There were no deaths. In 44% of the cases the person went to hospital, and 42% of the reactions started within minutes to 24 hours of use.

The FDA could not tell what caused them. It said it "cannot determine if the serious hypersensitivity reactions were triggered by the acne products' active ingredients, benzoyl peroxide or salicylic acid, the inactive ingredients, or by a combination of both."

Stop using the product and get emergency help right away if you have any of these signs, which the FDA lists:

• throat tightness
• difficulty breathing
• feeling faint
• swelling of the eyes, face, lips or tongue

The FDA also says to stop using the product if you develop hives or itching. The NHS gives the same advice for anaphylaxis, a severe allergic reaction: "a swollen throat or tongue, a raised, itchy rash and difficulty breathing," and to call emergency services.

The FDA says these serious reactions "differ from the local skin irritation," such as redness, burning, dryness, itching, peeling or slight swelling where you applied the product. Once you have had a serious reaction to a product, the FDA says not to use it again.

Test before you start. The FDA encourages every new user to follow this step: "apply a small amount to one or two small affected areas of the skin for 3 days. If no discomfort occurs, then the product can be used according to the directions on the Drug Facts label." Skinli's guide to patch testing explains how.

Sun sensitivity

The label says to "avoid unnecessary sun exposure and use a sunscreen," and to apply sunscreen after the product if you are going outside. The NHS says benzoyl peroxide "makes skin more sensitive to sunlight" and to avoid sunbeds and sunlamps. Skinli's plan uses benzoyl peroxide at night and sunscreen every morning.

Bleaching

Benzoyl peroxide bleaches hair and dyed fabric. The label says to "avoid contact with hair and dyed fabrics, which may be bleached by this product." The AAD calls the worry that it lightens skin "a myth." The bleaching guide covers towels, pillowcases and hair.

Benzene: what the FDA found

Benzene is a chemical that can cause cancer. The FDA says "benzoyl peroxide, a commonly used active ingredient in acne treatment drug products, may degrade into benzene under certain conditions (such as extreme temperatures)." The AAD says benzene "is not an intended ingredient" and forms most when products are exposed to high temperatures or stored for a long time.

The events, in order:

• March 2024. A paper in Environmental Health Perspectives, a journal published with support from the U.S. National Institutes of Health, found benzene in every benzoyl peroxide product sample it tested, with levels rising when the products were kept at body temperature and at higher storage temperatures. The work was paid for by Valisure, the private testing company that ran it.
• March 11, 2025. The FDA published the results of its own testing of 95 acne products with benzoyl peroxide. It found that more than 90% of the products had no detectable benzene or only the smallest amounts, and that six products had elevated levels. It said its results showed "fewer products with benzene contamination than the third-party findings."
• The recalls. The six products, and a seventh that its maker recalled after its own testing, were recalled from stores, which the FDA calls a retail-level recall. The FDA did not instruct consumers to act on products they already had.
• The FDA's risk statement. The FDA said that even with daily use of the recalled products for decades, the risk of developing cancer from the benzene found in them is low.
• March 24 to 25, 2025. The AAD issued a statement and a question-and-answer page. It said studies published in the Journal of the American Academy of Dermatology found that regular use of benzoyl peroxide acne products is "not linked to higher levels of benzene in the blood" and "not linked to an increased risk of developing cancer." It added that "current research on this topic is limited," and that "to date, there is no clear evidence that acne products containing benzoyl peroxide have dangerous levels of benzene."

The FDA also said some of the six products were near their expiration dates, and "recommends consumers check their products and throw away products that are beyond their expiration date."

What the AAD suggests if you are concerned:

1. Store benzoyl peroxide products as the package says, "at room temperature or cooler (e.g., refrigerated)."
2. "Replace products that contain benzoyl peroxide every 10-12 weeks."
3. "Throw out products exposed to higher temperatures (e.g., greater than 78°F)," such as a tube left in a hot car.
4. If you want to avoid benzoyl peroxide, consider "adapalene, salicylic acid, or azelaic acid," or talk with a dermatologist.

Pregnancy and breastfeeding

• AAD: benzoyl peroxide is "often found in acne treatment you can buy without a prescription, experts say it's safe to use in limited amounts. For this reason, you should talk with your obstetrician or dermatologist before using it while you're pregnant."
• NHS: "Benzoyl peroxide can usually be used during pregnancy, but it's best to check." For breastfeeding, the NHS says you may be able to use it, "but check with a pharmacist or doctor first," and to avoid using it on your breasts.
• Store labels: "If pregnant or breast-feeding, ask a health professional before use."
• Prescription gels with clindamycin: one label says there are no data on the gel in pregnant women, and that if it is used on the chest during breastfeeding, "care should be taken to avoid accidental ingestion by the infant."

Ask your doctor or pharmacist before you start, and tell them about every acne product you use.

Children and teenagers

The NHS says "most adults and children aged 12 years or older can use benzoyl peroxide." MedlinePlus says, "Do not use benzoyl peroxide on children less than 12 years of age without talking to a doctor." The prescription clindamycin and benzoyl peroxide gels are approved for patients aged 12 and older. Acne in a younger child is a reason to see a doctor first.

Who should not use it

The FDA label tells people not to use it if they have highly sensitive skin or "are sensitive to benzoyl peroxide." The NHS says it may not be suitable if you have had an allergic reaction to it, have a skin infection, or have "broken skin, cuts or grazes." Keep it away from the eyes, lips and mouth. The NHS says to get medical help if you swallow it by accident.

Using it with other acne products

The label warns: "skin irritation and dryness is more likely to occur if you use another topical acne medication at the same time." Some pairings are standard, such as benzoyl peroxide with adapalene, and others need a gap. See a retinoid with benzoyl peroxide and salicylic acid vs benzoyl peroxide. Prescription gels that add an antibiotic have their own warnings, covered in the clindamycin and benzoyl peroxide guide.

When to see a doctor

Get emergency help for throat tightness, trouble breathing, feeling faint, or swelling of the face, eyes, lips or tongue. See a doctor if irritation is severe, if you are pregnant or breastfeeding and want to start, if a child under 12 has acne, or if your acne has not improved after 12 weeks. For a plan built from a photo of your skin, try the free Skinli acne plan. Skinli gives general education. A doctor is the right person to diagnose and treat your skin.