Salicylic Acid (BHA)
Salicylic acid is a beta-hydroxy acid (BHA) and the most important exfoliant for oily, congested and acne-prone skin. Its defining characteristic is that it is oil-soluble — unlike AHAs, which are water-soluble and work on the skin's surface. Oil-solubility allows salicylic acid to penetrate into sebum-filled pores and exfoliate from within, making it uniquely effective for blackheads, whiteheads and congestion.
General Information Only. This page provides educational skincare information and is not medical advice. If you have persistent acne, eczema, rosacea, allergies, skin irritation, pigmentation changes or any medical skin condition, please consult a qualified dermatologist or healthcare professional before changing your skincare routine. Individual results vary. Always patch test new products.
How salicylic acid works
Salicylic acid is a keratolytic — it loosens and dissolves the bonds between dead skin cells, allowing them to shed more readily. Because it is oil-soluble, it can mix with the sebum lining pores and deliver this exfoliating action inside the pore itself. This is why it is so specifically suited to blackheads (open comedones) and whiteheads (closed comedones): the congestion that forms these is in the pore, not on the skin's surface.
Salicylic acid also has mild anti-inflammatory properties, which adds to its usefulness for acne-prone skin where inflammation plays a key role. Korean skincare uses it at gentler concentrations — typically 0.5–2% — in lightweight toner formats that suit oily skin without heaviness.
BHA vs AHA — key differences
Salicylic acid (BHA)
- ›Oil-soluble — penetrates pores
- ›Works inside the follicle on congestion
- ›Best for oily, acne-prone, congested skin
- ›Also mildly anti-inflammatory
AHAs (glycolic, lactic, mandelic)
- ›Water-soluble — work on skin surface
- ›Exfoliate the outer skin layer
- ›Best for dry, dull, textured, ageing skin
- ›Better for brightening and surface renewal
Concentrations guide
Very gentle. Daily use is possible for most oily skin types. Good starting point for those new to BHA or with slightly sensitive skin.
The sweet spot for most people. Effective for regular exfoliation and pore-clearing without excessive drying. Suitable for oily to combination skin.
Maximum OTC concentration in most markets. Most effective for blackheads and congestion. Use 2–3 times per week rather than daily.
Prescription-level in some countries. Not typically available in OTC Korean skincare products.
Best for and not suitable for
Best suited for
- ✓Oily skin
- ✓Acne-prone skin
- ✓Congested skin with blackheads or whiteheads
- ✓Combination skin with T-zone congestion
Use with caution
- ✕Dry skin — too drying at regular use
- ✕Sensitive or reactive skin — start low and infrequent
- ✕Compromised barrier — pause until barrier is restored
- ✕Pregnancy — salicylic acid at high concentrations should be discussed with your doctor