Sulfur

What it is

Sulfur is a yellow element and one of the oldest skin treatments on record. It loosens the dead cells that block pores, inhibits bacteria and the yeasts behind dandruff and seborrhoeic dermatitis, and mildly dries oily skin¹. Over-the-counter acne products may contain 3 to 10% sulfur²; combinations with the antibiotic sodium sulfacetamide are prescribed for rosacea, acne and seborrhoeic dermatitis¹.

What the evidence says

Evidence: moderate. A long record of use and regulator approval for acne; the best modern trials are of prescription sulfur plus sodium sulfacetamide for rosacea.

Sulfur's place in dermatology rests on decades of experience rather than large trials of sulfur alone¹. The sharpest evidence is for the prescription combination of 10% sodium sulfacetamide and 5% sulfur in rosacea. In a 12-week trial of 152 people, the combination cream reduced inflamed spots by 80%, compared with 72% for metronidazole cream, and improved redness in more people³. An eight-week study of a sulfacetamide-sulfur foam in 24 people with rosacea, seborrhoeic dermatitis or acne found improvement in all three groups: fewer inflamed rosacea bumps, better scores for the signs of seborrhoeic dermatitis, and acne counts halving, though it had no comparison treatment⁴. For plain over-the-counter sulfur you are relying on approved status and long history rather than head-to-head trials^{1, 2}.

It earns a place for people who cannot tolerate benzoyl peroxide or retinoids, and for rosacea-prone skin with acne-like bumps. Our rosacea and sensitive skin guide covers the wider picture.

How people use it

• Spot treatment or mask: a 3 to 10% sulfur paste on spots overnight, or a clay-sulfur mask on oily areas for 10 to 15 minutes once or twice a week.
• Leave-on lotion: a lower-strength sulfur lotion on the whole acne-prone area once daily, built up slowly.
• Prescription combinations: sulfacetamide-sulfur washes, lotions and foams, used as the prescriber directs.
• Dandruff and seborrhoeic dermatitis: some medicated shampoos and scalp preparations contain sulfur, often with salicylic acid¹.

Cautions

• Dryness, peeling and mild stinging are the usual side effects¹; moisturise and cut back if the skin feels tight, because over-drying triggers more oil and, in brown and Black skin, dark marks.
• It smells of rotten eggs; formulations mask it, but masks and pastes linger.
• Sulfa antibiotic allergy is a reason to avoid sodium sulfacetamide products; tell your prescriber³. Elemental sulfur is not a sulfa drug, but ask a pharmacist if unsure.
• Do not layer it with other drying actives such as benzoyl peroxide or retinoids until your skin has adjusted.
• Painful cysts, acne that scars, or rosacea with eye symptoms need a dermatologist, not a stronger sulfur product.