Sulfur
One of the oldest acne treatments, used for centuries. Sulfur has keratolytic (exfoliating), antimicrobial, and anti-inflammatory properties that make it effective for acne, seborrheic dermatitis, and rosacea. It has a distinctive smell but is gentler than benzoyl peroxide and works well for people who cannot tolerate BP or salicylic acid. Often found in traditional 'sulfur soap' and spot treatments.
Concentration & Usage
Concentrations: 2-10% in OTC products. Leave-on treatments: 3-8%. Wash-off: 5-10%. Can be used daily for mild acne. Sulfur masks (De La Cruz sulfur ointment) applied for 10-20 minutes are popular. Drying — follow with moisturizer.
Application
Topical (ointment, mask, cleanser, spot treatment). Leave-on or wash-off. Apply to clean skin.
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99%+ purity · third-party lab tested
Mechanism of Action
Elemental sulfur (S8) reacts with cysteine residues in stratum corneum proteins to form hydrogen sulfide (H2S) and thiol derivatives, reducing disulfide bonds in keratin K1/K10 and cornified envelope — loosening corneocyte cohesion and promoting desquamation. Breaks hyperkeratotic plug in follicular ostia, unclogging pores. Bacteriostatic against Cutibacterium acnes through metabolism and membrane disruption. Reduces sebum production, possibly via anti-androgenic effects on sebaceous glands. Antifungal against Malassezia furfur (seborrheic dermatitis, pityrosporum folliculitis) via ergosterol synthesis inhibition. Anti-inflammatory effects may involve H2S signaling — endogenous H2S has vasodilatory properties. Mild comedolytic. Well-tolerated: works primarily on stratum corneum without deep penetration.
Ingredient Interactions
Sulfur treatments and retinol are both drying. Using both in the same routine can damage the barrier. Use sulfur as a spot treatment or mask on non-retinol nights.
See our full Ingredient Interactions Guide for more combinations and timing strategies.
Regulatory Status
FDA-approved OTC acne drug ingredient. Available worldwide without prescription.
Risks & Safety
Common
Drying, distinctive rotten-egg smell, may bleach fabrics.
Serious
None at cosmetic concentrations.
Rare
Allergic reaction (sulfur allergy is distinct from sulfonamide or sulfite allergy).
Compare Sulfur With
Research Papers
10Published: October 17, 2023
AI Summary
Key to understanding the action of SM in the skin is the development of animal models that have a pathophysiology comparable to humans such that quantitative assessments of therapeutic drugs efficacy can be assessed.
Published: December 18, 2021
AI Summary
Body responses start with pruritus, erythema, edema and xerosis, which lead to the accumulation of immune cells in the target sites and recruitment of mast cells and paracrine-mediated activity. There is still no satisfactory countermeasure against SM-induced lesions in clinical therapy, and the symptomatic or supportive treatments are routine m...
Published: February 29, 1988
AI Summary
The smaller the particle size, the greater the degree of such interaction and the greater the therapeutic efficacy. One study showed that sulfur was comedogenic when applied onto human and rabbit skin, findings that were not reproduced in other studies.
Published: October 9, 2019
AI Summary
Positive outcome in two out of three key events indicates that the chemical can be categorized as a skin sensitizer. Altogether, following OECD requirements, our results suggest the classification of all investigated substances as skin sensitizers.
Published: December 23, 2010
AI Summary
Other clinical findings include erythema or painless sunburn, bulla, hypo- and hyper pigmentation in both exposed and unexposed areas (5,6) The mechanism and biochemical cascade of SM-induced cutaneous manifestations are not completely understood but several published pathways support many of the know facts.
Published: November 4, 2014
AI Summary
Tissue cultures showed no evidence of a microbial infection. The histopathologic findings and clinical course were consistent with a superficial second-degree burn.
Published: February 24, 2021
AI Summary
Decontamination efficacy was evaluated in pigs by measurement of lesion area and erythema (SM) and cholinesterase inhibition and clinical symptoms (VX). Following SM exposure, the two decontaminants demonstrated a significant decrease in lesions' size together with the decrease in exposure duration.
Published: October 18, 2023
AI Summary
To summarize presentations and discussions from the 2022 trans-agency workshop titled "Overlapping science in radiation and sulfur mustard (SM) exposures of skin and lung: Consideration of models, mechanisms, organ systems, and medical countermeasures."
Published: August 9, 2024
AI Summary
Exposure to SM results in various pathologies including skin lesions with subsequent impaired wound healing. Our findings expand the current understanding of SM-associated molecular toxicology in keratinocytes and highlight miR-497-5p as feasible clinical target for specific skin therapy in SM-exposed patients and beyond.
Published: August 14, 2020
AI Summary
These results demonstrate that inhibiting type IV collagenases in the skin improves basement membrane integrity after exposure to SM. BiPS may hold promise as a potential protective agent to mitigate SM induced skin injury.
Frequently Asked Questions
What is Sulfur used for?
One of the oldest acne treatments, used for centuries. Sulfur has keratolytic (exfoliating), antimicrobial, and anti-inflammatory properties that make it effective for acne, seborrheic dermatitis, and rosacea. It has a distinctive smell but is gentler than benzoyl peroxide and works well for people who cannot tolerate BP or salicylic acid. Often found in traditional 'sulfur soap' and spot treatments.
What are the side effects of Sulfur?
Common: Drying, distinctive rotten-egg smell, may bleach fabrics. Serious: None at cosmetic concentrations. Rare: Allergic reaction (sulfur allergy is distinct from sulfonamide or sulfite allergy).
How is Sulfur administered?
Sulfur is administered via topical (ointment, mask, cleanser, spot treatment). leave-on or wash-off. apply to clean skin..
Related Nootropics
Adapalene
A third-generation synthetic retinoid originally developed for acne that has significant anti-aging benefits. Adapalene is more stable than tretinoin (resistant to light and oxygen degradation) and better tolerated because it selectively binds to RAR-beta and RAR-gamma receptors rather than all three subtypes. The 0.1% concentration became available OTC in 2016 (Differin), making it the most accessible prescription-strength retinoid.
Adapalene
A third-generation synthetic retinoid specifically designed for acne treatment. Unlike tretinoin, adapalene selectively binds RAR-beta and RAR-gamma receptors in the skin, providing potent comedolytic and anti-inflammatory effects with significantly less irritation. It is also more stable in light and with benzoyl peroxide. Differin (0.1%) became OTC in 2016 — the first retinoid available without prescription in the US.
Azelaic Acid
A dicarboxylic acid naturally produced by yeast on the skin. Azelaic acid is a true multi-tasker that treats acne, rosacea, and hyperpigmentation simultaneously. It is one of the few active ingredients considered safe during pregnancy, and it uniquely targets only abnormal melanocytes — meaning it brightens dark spots without lightening normal skin. Effective for both inflammatory acne and post-inflammatory hyperpigmentation (PIH).
Azelaic Acid
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Benzoyl Peroxide
The most effective OTC acne treatment and one of the few topical treatments that kills acne-causing bacteria (C. acnes) without promoting antibiotic resistance. Benzoyl peroxide works through oxidation — it releases oxygen into pores, creating an environment where anaerobic bacteria cannot survive. It is one of three first-line acne treatments (alongside adapalene and salicylic acid) recommended by dermatological guidelines.
Benzoyl Peroxide
The most widely used OTC acne treatment and one of the only topical anti-acne agents to which bacteria cannot develop resistance. Benzoyl peroxide kills C. acnes through oxidative damage — releasing free oxygen radicals that the anaerobic bacteria cannot survive. It also has mild keratolytic and comedolytic (pore-unclogging) effects. Available in 2.5%, 5%, and 10% concentrations.