What Does Glycolic Acid Do? The Skincare Superstar Explained

In the vast and sometimes overwhelming world of skincare ingredients, a few names rise above the noise and earn a reputation as tried-and-true heroes.

Vitamin C has had its moment, hyaluronic acid is basically everyone’s best friend, and then there’s glycolic acid, the exfoliating ingredient that beauty editors, dermatologists, and skincare lovers swear by.

If you’ve ever wondered why glycolic acid is always in the spotlight and whether it deserves a place in your routine, this guide breaks it all down in the easiest, most relatable way possible.

What is Glycolic Acid?

Glycolic acid is an alpha-hydroxy acid (AHA). AHAs are a family of water-soluble acids known for their exfoliating properties. They’re typically derived from natural sources like sugarcane, but glycolic acid used in cosmetics today is usually produced synthetically to ensure purity and consistency.

It’s also the smallest AHA in molecular size (76 g/mol), which simply means it can penetrate the skin more effectively than many other acids. This tiny size is what gives glycolic acid its reputation as one of the most potent and reliable exfoliators on the market.

You’ll find it in a wide range of products, from facial exfoliants, toners, cleansers, brightening serums, peels, and even body lotions and shampoos.

What does glycolic acid actually do for your skin?

Think of glycolic acid as a gentle but determined skincare assistant sweeping away the clutter on your skin’s surface.

It exfoliates like a pro

Glycolic acid works by breaking the bonds that hold dead skin cells together. This helps them shed more easily, revealing fresher, smoother skin underneath. If your skin ever looks dull, flaky, or congested, adding glycolic acid to your skincare routine could transform your skin’s texture for the better.
It brightens and evens out your complexion

Regular exfoliation can fade hyperpigmentation, dark spots, acne scars, and general discolouration. That post-AHA glow people talk about? It’s real.
It softens fine lines and wrinkles

By removing the build-up of old skin cells, glycolic acid encourages collagen production over time. This can make the skin firmer, plumper, and more elastic.
It keeps pores clear

Glycolic acid helps loosen trapped sebum and dead cells inside pores, which makes it an excellent ingredient for anyone dealing with blackheads or frequent breakouts.
It boosts hydration

Surprisingly, exfoliating the skin can actually improve moisture levels. When dead cells are no longer sitting on the surface as a barrier, your hydrating products absorb better.
It has astringent and clarifying benefits

Glycolic acid is one of the most recommended skincare ingredients for oily or blemish-prone skin. It can help reduce excess sebum (oil) and refine skin texture

Who should be using glycolic acid?

Glycolic acid is brilliant for:

Oily skin because it helps control shine and keep pores clean.
Acne-prone skin because it reduces build-up that can cause breakouts.
Dull or uneven skin tone because it boosts radiance and smoothness.
Mature skin because it softens fine lines and encourages collagen.
Rough, textured skin, especially on the face, chest, back, or body.
Oily scalp or dandruff-prone hair, as glycolic acid works in shampoos too.

If you’ve been struggling with roughness, dullness, or stubborn dark spots, glycolic acid is often one of the first ingredients dermatologists recommend.

Who should not use glycolic acid?

While amazing, glycolic acid is not for everyone. You should avoid or be cautious if:

You have very sensitive or reactive skin (e.g., easily irritated skin).
You have active eczema, rosacea, or psoriasis in the application area.
Your skin barrier is compromised, which means your skin feels tight, sore, or stings easily.
You’re using prescription retinoids or other strong actives, and your skin is already irritated.
You’re new to exfoliants, and your skin is naturally delicate.

For darker skin tones, glycolic acid is safe, but it must be used carefully to avoid over-exfoliation, which can trigger hyperpigmentation. Start slow.

How should you use glycolic acid?

1. Start with a low percentage

Under 5%: great for hydration and mild exfoliation.
8–10%: for more visible resurfacing.
15%+: These are usually at-home peels intended only for experienced users.

2. Frequency matters

Begin by using it once or twice a week and then increase gradually as tolerated. Over-exfoliating leads to irritation, peeling, or breakouts.

3. Use only at night

AHAs increase your skin’s sensitivity to the sun, and no one is trying to gain new dark spots. But if you do decide to use it during the day, make sure you apply enough sunscreen.

4. Follow with hydration

Pair glycolic acid with a soothing moisturiser containing ingredients like:

Hyaluronic acid.
Ceramides.
Centella asiatica.
Niacinamide (if your skin can handle the combo).

5. Sun protection is non-negotiable

If you’re not wearing sunscreen daily, glycolic acid will do more harm than good. SPF 30 or higher is essential.

What can Glycolic acid be paired with?

Good pairings

These ingredients complement glycolic acid beautifully:

Hyaluronic acid, which restores moisture.
Niacinamide, which brightens and soothes (but some people prefer using it at a different time of day).
Ceramides, which strengthen the skin barrier.
Peptides that boost repair and plumpness.
Antioxidants (like vitamin E or green tea) reduce irritation and support skin healing.

Pair with caution

Retinol and retinoids can be too harsh together. Many dermatologists advise alternating nights.
Avoid using vitamin C (L-ascorbic acid) together with glycolic acid if you have sensitive skin, as it can be irritating.
Other exfoliating acids (salicylic acid, lactic acid), because you run the risk of over-exfoliating your skin.