Ingredients
What is glycolic acid (AHA) and what does it do?
Glycolic acid is the smallest alpha hydroxy acid (AHA). It loosens the bonds that hold dead cells together on the skin surface, creating a chemical exfoliation effect.
At a glance
- Best for
- Dull and rough skin, sun spots, fine lines, normal and oily skin
- Typical strength
- Usually 5–10% in leave-on products for home use
- When
- Evening; start with 2–3 times a week
- Pairs well with
- Hyaluronic acid, ceramides, panthenol, sunscreen in the morning
- Caution
- Retinol, BHA and vitamin C on the same night; irritated, sunburnt or very sensitive skin
What is glycolic acid?
Glycolic acid is a water-soluble acid that can be derived from sugar cane. Its small molecule penetrates skin the most easily among AHAs, which increases both its effect and its potential to irritate. Other AHAs such as lactic and mandelic acid have larger molecules and are usually gentler.
Benefits for skin
By speeding up the shedding of dead cells it makes skin smoother and brighter, and products applied afterwards absorb better. With regular use, sun spots and uneven tone fade and fine lines become less visible. Some studies suggest it supports collagen production even at low strengths.
How to use it
In the evening, apply it as a toner or serum on clean, dry skin, then moisturise. Start with two or three evenings a week. Brief tingling is normal; if burning and redness persist, use it less often.
AHAs increase sensitivity to the sun. Wear sunscreen every day while you use it and for a week after you stop.
Things to watch out for
Using it on the same night as retinol, salicylic acid or vitamin C increases irritation; alternate them. On deeper skin tones too much irritation can lead to post-inflammatory dark marks, so starting with a low strength is important. Glycolic acid at cosmetic strengths is generally considered acceptable in pregnancy, but check with your doctor.
Frequently asked questions
Can you use glycolic acid every day?
Low-strength (around 5%) toners can be used daily on some skin. For most people 2–4 times a week is enough; take a break if skin becomes dry and sensitive.
Is glycolic acid good for acne?
It can help with congestion by reducing dead-cell build-up, but salicylic acid, which works inside pores, is usually more suitable for acne.
Can you use glycolic acid with hyaluronic acid?
Yes. Applying hyaluronic acid and moisturiser after the acid reduces dryness and makes skin feel more comfortable.
This page is general information, not medical advice. If you have a skin condition, are pregnant or take regular medication, talk to a dermatologist before starting a new active ingredient.
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