Salicylic Acid (BHA)
An oil-soluble exfoliant that works inside the pore to help keep it clear of blackheads and congestion; the go-to acid for oily, blemish-prone skin.
salicylic acid, BHA, beta hydroxy acid, sodium salicylate, 2-hydroxybenzoic acid
Blemish-prone skin · Texture & large pores
What it does
Salicylic acid is the best-known beta hydroxy acid, or BHA, and the exfoliant of choice for oily, congested and blemish-prone skin. It helps clear the look of blackheads and whiteheads, keeps pores looking refined and, used regularly, helps keep skin clearer. It can also help calm the look of redness. You'll find it in cleansers, toners, serums and targeted spot gels, typically at 1 to 2%.
How it works
Unlike AHAs, which are water-soluble and work on the surface, salicylic acid is oil-soluble. That lets it travel into the oil-filled lining of the pore, where it loosens and dissolves the mix of sebum and dead cells behind blackheads and congestion, clearing blockages from within. Over time it refines texture and helps balance the look of shine. It works well alongside AHAs, used on alternate days or in balanced formulas: Biologique Recherche's Lotion P50 family contains it as salicylic acid or sodium salicylate.
MG says
For oily, congested skin, a BHA is your primary ally: start with 1 to 2% salicylic acid in a cleanser, toner or serum two or three times a week, and build up as your skin allows. My number one is Biologique Recherche's Lotion P50, a true facial in a bottle; of the P50 lotions, it has the highest level of BHAs.
Cautions
Salicylic acid can be drying, so introduce it gradually and follow with a moisturiser. Exfoliated skin can be more sensitive to the sun, so use a broad-spectrum sunscreen daily and for a week after use, and don't layer it with retinoids or other exfoliating acids on the same night. Avoid it if you're allergic to aspirin or other salicylates. If you're pregnant, trying to conceive or breastfeeding, check with your doctor, midwife or pharmacist before using it: low strengths (2% or less) are usually suggested, ideally in rinse-off products such as cleansers, and peels or extensive leave-on use are best avoided.
Regional notes
United States: Salicylic acid products that make acne claims (at 0.5–2%) are regulated as over-the-counter drugs; used purely as an exfoliant, it is a cosmetic ingredient.
United Kingdom: In the UK and EU, salicylic acid is capped at 2% in most cosmetic skincare (3% in rinse-off hair products), and it can't be used in products for children under three or in sprays that could be inhaled.
