Salicylic Acid
Also known as: BHA, beta hydroxy acid, 2-hydroxybenzoic acid
Salicylic acid is the only commonly used BHA in skincare, and its oil-solubility is what makes it special. It can penetrate into pores to dissolve the sebum and dead cells that cause blackheads and breakouts — something water-soluble AHAs simply can't do.
What It Does
Deep Dive
Why BHA Is Different
Salicylic acid's key advantage over AHAs is its lipophilicity — it dissolves in oil. This allows it to penetrate the sebaceous follicle and exfoliate inside the pore, making it uniquely effective against comedones (blackheads and whiteheads). No AHA can replicate this.
Anti-Inflammatory Benefits
Salicylic acid is derived from the same family as aspirin and shares anti-inflammatory properties. This dual action — exfoliation plus inflammation reduction — makes it particularly effective for acne, where both clogged pores and inflammation are in play.
Korean BHA Products
K-beauty BHA formulations tend to use betaine salicylate or willow bark extract alongside pure salicylic acid, resulting in gentler formulations. The COSRX BHA Blackhead Power Liquid, for example, uses betaine salicylate at 4% (roughly equivalent to 1% salicylic acid in potency).
How to Use It
Apply to clean skin, typically in the evening. Start with 2-3 times per week. Unlike AHAs, salicylic acid doesn't significantly increase photosensitivity, but sunscreen is still non-negotiable. It works best on oily and acne-prone skin types — dry skin types may find it too drying.
