Sulfur
Elemental sulfur in colloidal form. One of the oldest topical anti-acne ingredients. Disrupts hyperkeratosis at follicular openings and provides mild keratolytic and antibacterial effects. Used for acne and seborrheic dermatitis. The characteristic smell limits patient acceptability.
Evidence by route
Topical application
Topical sulfur 2-10% is included in AAD 2024 guidelines as an option for mild acne and rosacea (combined with sulfacetamide). The effect is modest compared with adapalene or benzoyl peroxide, but it is well tolerated in pregnancy.
- Zaenglein AL et al. J Am Acad Dermatol. 2016;74(5):945-973. PMID 26897386
How to read tiers A–F
- BLimited evidence. One RCT or several controlled studies with limitations
Tolerability and safety
- Irritation potential
- Medium
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Oily, Combination
- Use with caution
- Sensitive, Dry
About this ingredient
Sulfur (elemental colloidal sulfur) is one of the oldest topical anti-acne ingredients. In use since the late 19th century. Mechanism. On the skin it converts to hydrogen sulfide and polythionic acids that enter the follicle. Disrupts hyperkeratosis at follicular openings and delivers mild keratolytic effect. Antibacterial action against Cutibacterium acnes – via DNA synthesis disruption. Also suppresses Demodex folliculorum and Malassezia – relevant in rosacea and seborrheic dermatitis. Where applied. Acne products (Sulfur 5-10% mask, Mario Badescu Drying Lotion, Kate Somerville EradiKate), rosacea and seborrheic dermatitis treatments, perioral dermatitis lotions. In Spain – Letibalm, Acnomel. Evidence base. AAD 2024 recommends sulfur as an alternative when first-line agents (benzoyl peroxide, retinoids, azelaic acid) are not tolerated. Meta-analysis (Gupta 2004) showed moderate effect in acne and rosacea over 8-12 weeks. Efficacy is below benzoyl peroxide but tolerance is better. Safety. CIR confirmed safety up to 10% in leave-on and up to 20% in rinse-off. The characteristic 'rotten egg' smell limits patient acceptability. May over-dry skin with daily use above 5%. Non-sensitizing. Pregnancy and lactation – safe topically. AAD 2024 includes sulfur in first-line topical acne therapy in pregnancy (alongside azelaic acid, erythromycin, clindamycin). Suitable for. Inflammatory acne, rosacea, seborrheic dermatitis, perioral dermatitis, demodicosis, fungal acne. Especially useful in pregnancy when retinoids and tetracyclines are contraindicated.
Frequently asked questions
Is Sulfur safe during pregnancy?
Sulfur is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Sulfur for?
Sulfur suits: oily, combination. Use with caution in: sensitive, dry.
Can Sulfur irritate the skin?
Sulfur has moderate irritation potential. Sensitive skin may show a transient reaction that usually settles with adaptation.
What is Sulfur and what does it do in cosmetics?
Elemental sulfur in colloidal form.
Is Sulfur comedogenic?
On the Fulton scale 0/5 – non-comedogenic. For acne-prone skin, a rating of 3 or higher suggests choosing an alternative.
What's the INCI name for Sulfur?
The INCI name is Sulfur. It may also appear as: Colloidal Sulfur, Precipitated Sulfur.
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