Salicylic Acid (0.02%)
Salicylic acid (SA) is a beta-hydroxy acid (BHA) that is lipid-soluble, allowing it to penetrate into pores and shed dead skin cells from within. It is used in cosmetics at concentrations of 0.5–2% for at-home use, with professional peels ranging from 20–30%. Its chemical structure is closely related to aspirin, contributing to its anti-inflammatory properties. It is also recognized as a preservative and keratolytic agent under official CosIng classifications.
Salicylic acid exfoliates both on the skin surface and inside pores, making it particularly effective against blackheads and helpful in preventing acne formation. It is a potent anti-inflammatory agent useful for acne and rosacea, and studies at 2% show it does not increase sun sensitivity and may have photoprotective effects. It is most effective for blackheads and non-inflamed blemishes; for inflamed acne, it works best when combined with antibacterial agents such as benzoyl peroxide or azelaic acid.
At the concentration noted (0.02%), effects are minimal; however, at active concentrations (0.5–2%), it should be used with caution on sensitive or compromised skin. The source notes SA at 2% does not increase sun sensitivity, but sunscreen use is still recommended. In the EU, 2% is the maximum permitted concentration for at-home products. Professional peels (20–30%) carry higher risk and should be administered by trained practitioners.
