Acne Treatments (Benzoyl Peroxide, Salicylic, Azelaic, Glycolic, Sulfur)

Pregnancy

ACOG lists four over-the-counter topical ingredients, while AAD describes limited-amount benzoyl peroxide and time-limited salicylic acid. AAD's pregnancy skin-care page says to use salicylic acid above 2% sparingly. MotherToBaby reports that only a small amount of topical acne treatment is usually absorbed, with more possible through broken or irritated skin, frequent use, or application over a large area. Ly et al.'s narrative review says clinical studies of common acne treatments in pregnancy are limited, notes that formal studies of sulfur in pregnancy are lacking, and flags increased salicylic-acid absorption with large-area, prolonged, or covered use. The September 2024 EMA/CMDh variation sets product-information limits for specified salicylic-acid medicines: for ointments, 100 mg/mL solutions, patches, gels, and adhesive plasters, it limits use to short-term treatment of a small single skin area; it gives a separate, stricter schedule for some 10% scalp medicines and says products for ophthalmic use may be used at intended use because systemic exposure is negligible. These product-specific instructions do not automatically describe every low-strength cosmetic or acne product. The cited primary studies measured absorption and metabolism, not pregnancy outcomes.

Breastfeeding

LactMed's salicylic-acid record says no clinical skin-use information is available for breastfeeding and no relevant published maternal levels, infant levels, or infant-effect information was found as of its June 2021 revision. LactMed says topical use is unlikely to be appreciably absorbed or appear in milk, and it advises against application where the infant can touch or lick treated skin. MotherToBaby says most over-the-counter topical acne treatments have not been well studied while breastfeeding and expected milk amounts are likely low; it advises against applying treatment to the nipple or areola, washing products off the breast or chest before feeding, and washing hands. NHS says benzoyl peroxide may be used after advice from a pharmacist or doctor and says not to use it on the breasts. These are product and contact precautions, not evidence of measured infant outcomes for all five ingredients.

What was tested

Fung et al. (2008) ran a single-center crossover pharmacokinetic study in nine healthy adult subjects. It compared a 30% salicylic-acid facial peel applied for five minutes with 650 mg oral aspirin. Mean peak salicylic-acid concentration was 0.81 micrograms/mL after the peel and 56.4 micrograms/mL after oral aspirin. One author was affiliated with L'Oreal USA. The study measured adult blood levels, not pregnancy or breastfeeding outcomes, and its 30% peel is not the same as a routine low-strength leave-on or rinse-off product. Nacht et al. (1981) studied benzoyl-peroxide penetration in excised human skin and rhesus monkeys; it was not a pregnancy study. No pregnancy or infant outcome was tested in these two primary studies.