Salicylic Acid (045%)
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 products, 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 the skin surface and inside pores, making it particularly effective against blackheads and whiteheads. It acts as a potent anti-inflammatory agent, beneficial for acne and rosacea. At 2%, studies show it does not increase sun sensitivity and may even have photoprotective effects.
For inflamed acne, SA alone is only moderately effective and works best when combined with antibacterial agents such as benzoyl peroxide or azelaic acid. In the EU, the maximum permitted concentration for at-home use is 2%. Professional-strength peels (20–30%) should not be used without supervision.
