COSRX AHA 7 Whitehead Power Liquid ingredients

What should you look for on the ingredient list?

AHA means alpha hydroxy acid, a group of acids used in skincare. Common ingredient names include glycolic acid and lactic acid; other AHAs include citric acid, malic acid and tartaric acid. These are names to recognise on a label, not a confirmed ingredient list for this COSRX toner. Cosmetic products sold at retail in the US must carry an ingredient declaration.14

Do not treat the product name as confirmation of a particular acid concentration or pH. AHA exfoliation depends on the acid used, its concentration, the formula's pH and the other ingredients. A percentage alone cannot tell you how strongly a product will exfoliate.1

Is the BHA ingredient list interchangeable?

No. COSRX BHA Blackhead Power Liquid lists willow bark water, betaine salicylate and niacinamide among its ingredients. Those ingredients should not be copied into an AHA 7 ingredient list. The AHA and BHA names look similar, but "Power Liquid" is not a family recipe.2

What do AHAs do?

AHAs loosen the connections between dead cells on the skin's surface, helping those cells shed. This can improve surface texture and give skin a more even appearance. Glycolic acid also helps unclog pores, but that general ingredient benefit is not a promise that this toner will clear every whitehead. With cosmetic glycolic acid products, improvements in brightness or uneven pigmentation can take several months of consistent use.45

What matters before using an AHA toner?

Follow your bottle's directions. These are general precautions for AHA exfoliants, not a substitute for COSRX's product instructions.

• If the label lists glycolic acid, test a small area first. General glycolic acid guidance is to start once or twice weekly at night and increase only if your skin tolerates it.
• Keep other exfoliating acids, retinol and vitamin C out of the same routine when first introducing glycolic acid. Prescription retinoids and benzoyl peroxide can also make exfoliation more irritating.
• Apply moisturizer after exfoliating. Oily skin still needs moisture; an acid is not a reason to skip it.
• Use sunscreen, protective clothing and limited sun exposure while using AHAs and for a week after stopping. For glycolic acid, use broad spectrum SPF 30 or higher during the day.
• Do not exfoliate sunburned skin or areas with open cuts or wounds. Stop or reduce use if irritation develops.
• Be cautious with glycolic acid if you have sensitive or dry skin, rosacea, eczema or an active skin infection. If pregnant or breastfeeding, check with your healthcare provider before using glycolic acid.