Sulfur

Antimicrobial and keratolytic mineral for acne-prone skin.

Also known as: Sulfur, precipitated sulfur, colloidal sulfur, sublimed sulfur

What it is

Sulfur is a naturally occurring mineral element used in skincare as a fine powder or colloidal suspension. It has been used in dermatology for over a century, particularly for acne and other inflammatory skin conditions.

What it does

Sulfur works through multiple mechanisms: it reduces *Cutibacterium acnes* (formerly *Propionibacterium acnes*) and other acne-causing bacteria, promotes keratin breakdown to unclog pores, and has mild anti-inflammatory properties. It also helps normalize sebum production, making it effective for both comedonal and inflammatory acne.

The evidence

Strong clinical evidence supports sulfur's efficacy for mild-to-moderate acne; multiple studies confirm its antimicrobial and keratolytic activity. Evidence is particularly robust for combination formulas (sulfur + salicylic acid or resorcinol), though sulfur monotherapy also shows consistent results.

Best for

Oily, acne-prone skin with comedones and mild-to-moderate inflammatory acne; also effective for rosacea and seborrheic dermatitis.

Pairs well with

Salicylic acid, benzoyl peroxide, niacinamide, azelaic acid, and zinc. Classic combinations with resorcinol are still used in prescription formulas.

Use cautiously with

Retinoids and vitamin C (risk of irritation and reduced efficacy); use cautiously with other keratolytics or strong actives to avoid over-exfoliation. Avoid combining with benzoyl peroxide in the same product (may reduce efficacy).

Cautions

Sulfur has a distinctive unpleasant odor that can be off-putting; it may cause dryness, mild irritation, or contact dermatitis in sensitive individuals. Generally safe in pregnancy but consult a provider; not recommended for those with sulfur allergy (rare but possible).