Is sulfur safe for acne during pregnancy?

What does the evidence say about sulfur acne products during pregnancy?

1. ACOG's specifically named list of OTC topical acne ingredients considered usable in pregnancy includes benzoyl peroxide, azelaic acid, salicylic acid, and glycolic acid; sulfur-sulfacetamide is not on that particular named list even though it is commonly recommended in dermatology practice, and OTC topical acne products overall have not been associated with an increased chance of birth defects. 1
2. Sodium sulfacetamide works by inhibiting a bacterial enzyme involved in folic acid production; despite that theoretical mechanism, no reports of congenital anomalies have been linked to sulfacetamide, and the combination of sulfacetamide and sulfur is described as not contraindicated during pregnancy, though it historically carried an FDA Category C label. 2
3. A separate published reference table instead lists topical sodium sulfacetamide under FDA Category B, a milder label than the Category C cited elsewhere; this kind of disagreement between reference sources is itself a reason this page stays an evidence summary rather than a settled safety claim. 3
4. Topical sulfur at 5 to 10 percent in a petrolatum base is established as safe for direct use on infants under 2 months old, including for scabies infestations, though that same petrolatum base is considered unsuitable for use directly on the breast; specific data on maternal or infant levels from the sulfacetamide-sulfur combination used for acne has not been published. 4
5. In one documented case, a sodium sulfacetamide and sulfur lotion was used as an add-on option alongside other prescribed therapy for severe pregnancy acne, with a significant decrease in the number and size of inflammatory lesions observed by week 34, illustrating provider-directed use rather than a stand-alone, self-started product. 2

Is sulfur acne products safe in each trimester?

• First trimester. Acne often flares early in pregnancy as hormones shift. Sulfur-based products are one of the topical options dermatology sources describe as compatible with pregnancy, but bring any acne regimen change to your prenatal visit rather than starting on your own.
• Second trimester. If a sulfur wash or spot product worked before pregnancy, providers generally see no reason to stop it now. Keep it to the areas that actually break out, since sulfur can be drying.
• Third trimester. No specific date to stop a sulfur-based acne product before delivery is established in the sources reviewed here. Continue it the way your provider approved, and mention it to your delivery team along with anything else you're using on your skin.