Alpha Hydroxy Acids (AHAs): How to Use Them Without the Guesswork

Want smoother, brighter skin but confused by all the acids out there? Alpha hydroxy acids, or AHAs, are water‑soluble exfoliants that loosen the glue between dead skin cells. That helps pores look smaller, fine lines soften, and skin tone even out. They’re simple to add to a routine — if you know which AHA to pick and how to use it safely.

Which AHAs work best for you?

Glycolic acid is the most common. It’s small, strong, and great for rough texture and dullness. Start low if you’ve never used acids. Lactic acid is gentler and attracts moisture, so it’s a good first choice for dry or sensitive skin. Mandelic acid has a larger molecule and causes less irritation — better for rosacea or very reactive skin. There are also malic, citric, and tartaric acids, but glycolic and lactic are the ones you’ll see most.

Think about what you want: surface smoothing and brightening? Glycolic. Hydration and a mild glow? Lactic. Acne and oil control? Consider a BHA (salicylic acid) instead — it penetrates oil better. AHAs treat the skin’s surface, BHAs work deeper in pores.

How to use AHAs safely and effectively

Start slow. Use an AHA product every 2–3 nights for the first two weeks, then increase frequency if your skin tolerates it. For leave‑on serums or creams, beginners should try formulas in the 5–10% range (or lower for glycolic). Stronger over‑the‑counter options exist, and professional peels are much stronger — those should be done by an esthetician or dermatologist.

Pay attention to pH. AHAs work best at lower pH (around 3–4). Many well‑formulated products balance concentration and pH for safety. Always patch test: apply a small amount behind your ear or on your inner forearm and wait 24–48 hours.

Don’t mix harsh actives all at once. Using AHA and retinol on the same night often causes irritation. If you use both, alternate nights or use AHA in the morning and retinol at night — but avoid AHA + vitamin C together if you find your skin gets red or tight. Moisturize after an AHA to lock in hydration.

Sunscreen is non‑negotiable. AHAs thin the very top layer of dead skin, making you more sensitive to UV. Use SPF 30+ every morning and reapply during the day when you spend time outside.

Finally, skip AHAs on broken, sunburned, or inflamed skin. If you get severe redness, swelling, or persistent stinging, stop use and talk to a dermatologist. For most people, AHAs are a fast, straightforward way to improve texture and tone — just start slow, protect your skin, and pick the acid that matches your needs.