Colloidal sulfur is a finely dispersed form of elemental sulfur used in topical formulations to treat acne, rosacea, seborrheic dermatitis, and other conditions. It exerts keratolytic, antibacterial, antifungal, and mild antiparasitic effects.
| Reported effect | How often | Notes |
|---|---|---|
Skin dryness and peeling | Common | Result of its keratolytic action, especially at higher concentrations. |
Local irritation, redness, or stinging | Common | More likely on sensitive or compromised skin. |
Unpleasant odor | Common | Characteristic sulfurous smell, more of a tolerability than safety issue. |
Contact dermatitis | Uncommon | Irritant more often than allergic; true sulfur allergy is infrequent. |
Allergic contact sensitization | Rare | Documented in case reports but considered uncommon overall. |
Systemic toxicity from absorption | Very rare | Reported historically with extensive application over large areas, particularly in infants. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.