AHA Exfoliation Explained: How Glycolic & Lactic Acid Transform Dull Skin

If your skin looks dull, rough, or "grey" no matter how much you moisturise, dead skin cell build-up is usually the culprit — and AHA is the ingredient built to fix it.

Eastern Curlew  ·  Skincare Ingredients  ·  3 minute read

What is AHA?

AHA (alpha hydroxy acid) is a family of water-soluble exfoliating acids — the best known being glycolic acid (from sugar cane) and lactic acid (from milk). They work on the skin's surface, loosening the bonds holding dead cells in place so they shed evenly, revealing fresher skin underneath.

What AHAs do for your skin

• Instant brightness — dull, flaky surface cells are swept away
• Smoother texture — rough patches and uneven grain soften with regular use
• Softens the look of fine lines — glycolic acid supports collagen over time
• Fades post-blemish marks — faster surface renewal means faster fading

AHA vs BHA — a 10-second guide

AHA = surface exfoliation → dullness, texture, glow. BHA = inside-the-pore exfoliation → blackheads, congestion. Combination AHA/BHA toners handle both in one step, which is why they've become a K-Beauty staple.

How to use AHA safely

1. Start with 2 nights per week, on cleansed dry skin
2. Follow with hydrating toner, essence, and moisturiser
3. Non-negotiable: SPF every morning — AHAs increase sun sensitivity
4. Skip AHA on nights you use retinol until your skin is well adjusted

FAQ

Can I use AHA every day?

Most skin does best at 2–4 nights per week. Daily use suits only very resilient skin with low-strength formulas.

Is lactic acid gentler than glycolic?

Yes — its larger molecule penetrates more slowly, making it the better starting point for sensitive skin.

Can I use AHA and vitamin C together?

Use vitamin C in the morning and AHA at night to get both without irritation.