Colloidal Sulfur Bad Irritant Anti-Blemish Colloidal Sulfur at a glance Smaller particles than sulfur, making it more potent Anti-acne properties help tackle breakouts Can cause skin irritation and sensitization Most effective in skin care preparations between 3% and 10% Colloidal Sulfur description Colloidal sulfur is a skin care ingredient that’s often used in products for its anti-acne properties. It differs from traditional sulfur in that it’s engineered to have much smaller particles, boosting the potency of this over-the-counter active. How colloidal sulfur works for acne is more theory than fact. According to one overview, its keratolytic (exfoliating) action “...is thought that sulphur interacts with cysteine in keratinocytes resulting in the production of hydrogen sulphide, which has a keratolytic effect by rupturing the disulphide bonds of cysteine molecules in keratin.” Sulfur’s antibacterial properties help inhibit the overproliferation of acne-causing bacteria. Topical application of sulfur and colloidal sulfur can irritate skin, causing mild sensitization (extreme adverse events are considered rare). Seeking out less-irritating, research-backed, anti-acne ingredients like benzoyl peroxide should be your first course of action before implementing colloidal sulfur or sulfur into your skin care routine. According to suppliers, colloidal sulfur is effective for anti-acne purposes at 3-10%. Outside of skin care, sulfur and colloidal sulfur are commonly used in hair care products to combat dandruff. For these purposes, colloidal sulfur is most effective in amounts between 2% and 5%. Compared to traditional preparations of sulfur, the colloidal form dissolves much more readily in water and is a finely milled pale, yellow powder in its raw material state. It maintains the unpleasant odor sulfur has, one more reason it’s less appealing than other anti-acne actives. Related ingredients: Sulfur