Salicylic Acid (BHA)

What is salicylic acid and what does it do?

Salicylic acid is an organic acid related to compounds found naturally in willow bark, and today it is mostly produced synthetically. In cosmetics it is known for its keratolytic effect: it loosens the bonds between dead cells, helping the skin's surface to renew.

Unlike water-soluble AHAs such as glycolic acid, it is also oil-soluble. This lets it penetrate the sebum inside the pores and help clear blockages. It also has a mild soothing effect, which makes it popular for acne-prone skin.

Which products contain it?

• Gels, toners and serums targeting acne and blackheads
• Facial cleansing gels
• Anti-dandruff shampoos
• Products for corns and hardened skin

On the label it is listed as Salicylic Acid. In cosmetics it is sometimes also used at low concentrations as a preservative. High-strength products used to treat warts and corns, however, are classed as medicines.

Is it harmful? The scientific assessment

At cosmetic concentrations, the most common side effects of salicylic acid are dryness, flaking, stinging and redness. These effects usually ease by using the product less often or supporting it with a moisturiser.

Under EU chemical classification, salicylic acid is among the substances suspected of reproductive toxicity. This classification is based on high doses. The EU's scientific committee, the SCCS, has concluded that it is safe when used below the upper limits set for cosmetics. In the EU its concentration is limited in most products, and it is not used in products intended for children under three, except shampoos. Turkish cosmetics legislation is also aligned with the EU.

Salicylic acid is related to aspirin; for this reason, reactions can occur in people who are allergic to aspirin or salicylates.

Who should be careful?

• Pregnant and breastfeeding women: Low-strength products applied to small areas are considered low risk; still, it is recommended to consult your doctor, especially before peels or use over large areas.
• People with an aspirin or salicylate allergy: It is a good idea to consult a doctor before use.
• Very dry, eczema-prone or rosacea-prone skin: Irritation can develop more easily.
• Young children: Its use in products for children is restricted.

What to do when you see it on a label

If you have problems with pores and acne, salicylic acid is an effective option. You can start once a day or every other day and increase according to how your skin responds. Using it on the same evening as strong actives such as retinol can increase irritation. Moisturisers containing niacinamide or ceramides are good companions for supporting the skin barrier. As exfoliating products can increase sun sensitivity, use sunscreen during the day.