Alpha Hydroxy Acids (AHAs): What They Do and How to Use Them

Want smoother skin without harsh scrubs? AHAs are chemical exfoliants that dissolve the glue between dead skin cells so they shed faster. That means less roughness, fewer clogged pores, and a brighter tone over weeks. Used right, they can seriously improve texture. Used wrong, they cause redness and sensitivity—so here's a clear, practical playbook.

Which AHA suits your skin?

Glycolic acid is the workhorse. It’s small, penetrates well, and shows results fast. Good for uneven tone and fine lines. Start at 5–10% for leave-on products and move up if your skin tolerates it. Lactic acid is gentler and draws moisture into skin—great if you’re dry or sensitive. Mandelic acid is larger, less irritating, and helpful for acne-prone or rosacea-prone skin. Citric and malic acids appear in lower concentrations in many blends to boost brightness, but they’re usually not primary active ingredients.

Check the label: concentration and pH together determine strength. A product with 10% glycolic at pH 3 works harder than the same concentration at pH 4.5. If brands don’t list pH, stick with known, reputable formulas and lower concentrations until you know how your skin reacts.

How to use AHAs safely

Patch test on your jawline or inner forearm for 24–48 hours before full-face use. Start slow: apply once every 3–4 nights, then move to every other night if you tolerate it. If you get persistent stinging or blistering, stop and see a dermatologist.

Sunscreen is non-negotiable. AHAs thin the outer layer of dead skin and make you more sun-sensitive. Use a broad-spectrum SPF 30+ daily and avoid prolonged sun in the first week after starting an AHA.

Mixing rules: don’t layer strong AHAs with retinoids or vitamin C the same night unless you’re experienced—this combo often causes irritation. Either alternate nights (AHA one night, retinoid the next) or use vitamin C in the morning and retinoid/AHA at night. If you use benzoyl peroxide for acne, watch for drying and redness when combined with AHAs.

Avoid applying AHAs to broken or sunburned skin. Pregnant or breastfeeding? Many topical AHAs have low absorption, but talk to your provider before starting stronger treatments.

Product tips: serums and leave-on acids deliver the best results; cleansers give a mild, short contact exfoliation and are gentler. For visible texture change, choose leave-on treatments with clear active percentages and follow the brand’s instructions. If you want faster, stronger results, consult a dermatologist about in-office peels or prescription options.

Used thoughtfully, AHAs can refresh dull skin and smooth rough patches. Start low, protect from sun, and adjust based on how your skin responds. If you’re unsure, take a photo each week to track progress—slow, steady improvements are the goal.