What Is Glycolic Acid And How Do I Use It?

Anything with the word acid in its name might seem intimidating at first, but don’t be fooled, glycolic acid is a naturally-occurring and totally skin-friendly ingredient which is much more likely to clear your acne and brighten your skin than it is to burn your face off. Here’s everything you need to know.  

What is glycolic acid?

Glycolic acid is a chemical exfoliant known as an alpha hydroxy acid (AHA). It’s a naturally occuring ingredient derived from plants like pineapple and sugar cane. Glycolic acid is the most popular AHA because it’s the strongest, and thanks to its small molecule size has the ability to penetrate skin deeply and easily. 

How does it work?

Glycolic acid breaks down sebum and the other substances that bind cells together in order to remove dead skin cells and the top layer of skin, so that the fresh, new skin cells of the layer below can shine through. Over-use can lead to redness and irritation, but essentially glycolic acid is suitable for any and every skintype, and is a much gentler alternative to physical scrubs because it won’t tear the skin (which can lead to further long-term damage). 

Why should I use it?

If your skin looks dull, feels rough, frequently breaks out, or has red marks and scars left behind from spots, then glycolic acid can benefit you.  

Breakouts – Because glycolic acid removes the dead skin cells that block pores, it means that pores are less easily clogged, so you’ll experience fewer breakouts.  

Pigmentation/scars – Glycolic acid also helps with the marks left behind by breakouts – pigmentation only effects the top layers of skin, so with every layer of skin that’s removed, scars will appear more faded and less obvious. 

Dull skin – Skin appears dull and grey when pores are clogged with oil and dead skin, so once these are removed, your complexion will appear fresher and brighter. 

Rough texture – Like physical scrubs, glycolic acid helps to slough away rough and flaky patches of skin. It also helps to transfer water molecules from the air to the skin, so it replenishes lost moisture. 

Mature skin – Glycolic acid can help skin that has a lot of sun-induced pigmentation (brown spots). It also helps to stimulate the production of collagen – an ingredient which makes skin appear smoother and plumper. 

When should I use it?

In your evening skincare routine – glycolic acid increases skin’s sensitivity to the sun so it’s safer to use it at night time (make sure to wear an SPF the following day). Your skin might need getting used to glycolic acid if you’ve never used it before – it can cause redness and flaking – so start off by using it once a week and gradually increase to see how your skin adapts. It’s also important to be careful what ingredients you pair glycolic acid with – it can cause a reaction if you use it with products containing vitamin A/retinol, so it’s best to avoid layering with other active ingredients. 

Beauty Editor's Picks

Because this is pure glycolic acid, it’s much more effective than those products which combine glycolic with other ingredients, but it’s also more likely to cause a reaction, so should be used carefully to begin with. Of all the products I’ve tried, this has the fasted and most obvious results – clearer, brighter skin in no time at all. 

To apply: After you’ve cleansed, soak a cotton pad in the solution and spend a few minutes sweeping it over and pressing it into skin. Allow to fully absorb before applying your serum and moisturiser. 

Glycolic acid cleansers are particularly good for keeping skin clear if you find it’s easily congested. Suitable for both morning and evening cleansing (because it’s quite gentle), this gel-textured face wash foams easily (so you only need the smallest amount) and does a good job of reducing breakouts and leaving skin smoother. 

To apply: Rub a coin-sized amount onto damp skin and take time to massage into effected areas before rinsing away residue.