Ingredient type
Alpha hydroxy acid (AHA), from sugarcane
Beginner concentration
1–5%
Best for
Dullness, uneven texture, mild hyperpigmentation
Glycolic acid is an alpha hydroxy acid (AHA) derived from sugarcane, and it’s the most widely studied and used AHA in skincare. It has the smallest molecular size of any AHA, which lets it penetrate the skin deeply and efficiently — making it highly effective, but also the AHA most likely to cause irritation if you move too fast.
What glycolic acid does for skin
- Exfoliates dead skin cells — breaks down the bonds holding dead cells together, revealing smoother, brighter skin underneath
- Brightens and evens tone — helps fade hyperpigmentation and dullness with consistent use
- Improves texture — regular use smooths rough texture and can help prevent clogged pores
- Boosts collagen at higher concentrations — genuinely unique among AHAs; glycolic acid has been shown to stimulate collagen synthesis and increase epidermal hyaluronic acid
What percentage of glycolic acid should you use
| Concentration | Best for | What to expect |
|---|---|---|
| 1–5% | Beginners, sensitive skin, daily use | Gentle surface exfoliation, low irritation risk |
| 5–10% | Most skin types, regular use 2-3x/week | Improves tone, texture, and mild hyperpigmentation |
| 10–20% | Experienced users, advanced concerns | Stronger anti-aging and pigmentation benefits, used less frequently |
| 20%+ | Professional peels only | Should only be performed by a dermatologist, not for home use |
A 10% glycolic acid formulated at pH 3.0–3.5 is meaningfully more active than a 15% product at pH 4.5+. If a brand doesn’t list their product’s pH, that’s worth factoring into your decision.
Who should use glycolic acid
Suitable for most skin types when introduced gradually, and particularly effective for dullness, uneven texture, mild hyperpigmentation, and early signs of photoaging. Beginners to chemical exfoliation often start here, though those with very sensitive skin may find mandelic acid a gentler starting point.
What to pair glycolic acid with — and what to avoid
Combining glycolic acid with retinol and other exfoliating acids like salicylic acid raises irritation risk considerably. Many people alternate glycolic acid and retinol on different nights rather than using both together.
Glycolic acid increases photosensitivity meaningfully — daily broad-spectrum sunscreen isn’t optional alongside it.
Frequently asked questions
Is glycolic acid safe during pregnancy?
Low concentrations (under 10%) are generally considered safe, since it works on the skin’s surface rather than being absorbed in meaningful amounts — but always confirm with your doctor, and avoid higher-concentration professional peels.
What’s the difference between glycolic acid and salicylic acid?
Glycolic acid (an AHA) works on the skin’s surface for dullness and texture; salicylic acid (a BHA) is oil-soluble and penetrates into pores, making it better for acne and blackheads.
How often should beginners use glycolic acid?
Start with 2-3 times a week at a low concentration (5-10%), and build up frequency gradually as your skin builds tolerance.
Is a slight stinging sensation normal?
Yes, mild tingling is expected and often indicates the product is biologically active — but excessive burning suggests the concentration or pH isn’t right for your skin.