Let’s talk about glycolic acid, the “miracle” ingredient that every beauty influencer seems to be talking about on TikTok.
Glycolic acid is an alpha-hydroxy acid (AHA), which is a fancy way of saying it’s a chemical exfoliant. But what makes it special is its size. Glycolic acid has the smallest molecule among the AHAs commonly used in skincare, which allows it to penetrate the skin more readily than larger AHAs such as lactic or mandelic acid. Small molecule, big results.
What Does It Do?
The core job of glycolic acid is dissolving the “glue” that holds dead skin cells together on the skin’s surface. When those dead cells slough off, what’s underneath is fresher, smoother, and more even. That’s the foundation of everything else it does.
From there, the benefits stack up. Regular use can help improve skin luminosity and even out tone, which is a polite way of saying dull, patchy skin starts looking like it reflects light. It can also soften the appearance of fine lines and wrinkles over time, with research suggesting that AHAs such as glycolic acid can support collagen production. It’s not a magic eraser, but it can be an effective over-the-counter option for gradual, visible improvement.
Acne-prone? Glycolic acid can help there, too. By exfoliating the skin’s surface, it can help prevent dead skin cells from contributing to clogged pores and breakouts. It may also help fade the dark marks that acne can leave behind.
So What About Your Scalp?
Here’s where it gets interesting. Glycolic acid isn’t just a face thing. Applied to the scalp, it can exfoliate in much the same way – helping to remove dead skin cells and product build-up. If you deal with a dry or flaky scalp, or use a lot of dry shampoo and styling products, a glycolic acid product specifically formulated for the scalp may help remove surface build-up before shampooing.
The scalp has plenty of sebaceous glands, which means it can become oily and congested in its own way. Glycolic acid can help remove build-up and leave the scalp feeling cleaner. However, more isn’t necessarily better: the scalp can be sensitive, so it’s important to use products as directed and stop if irritation develops.
Choosing the Correct Concentration
Concentration matters. The US Food and Drug Administration (FDA) has warned consumers about certain high-concentration chemical peel products, including those containing glycolic acid, because they can cause serious skin injuries when used incorrectly or without appropriate professional supervision. That is not what we’re talking about here.
A seven per cent glycolic acid toner can be a reasonable starting point for some people using an at-home product, but there is no universal “sweet spot”. Skin type, formulation, and frequency all matter, and a lower concentration may be more appropriate for sensitive skin.
How to Use It
Start slow. This is non-negotiable. Even at seven per cent, glycolic acid is an active ingredient, and your skin may need time to adjust. Two or three nights a week is plenty to start. Some people can work up to more frequent use, but there’s no prize for rushing it.
Use it at night if that suits your routine. Glycolic acid and other AHAs can increase the skin’s sensitivity to sunlight, so daily broad-spectrum sunscreen is essential. You’re also deliberately exfoliating the outermost layer of skin, so protecting what’s underneath matters.
Don’t layer it with every other active. Retinol, salicylic acid, lactic acid – you don’t need to throw everything at your skin at once. Keep the rest of your routine simple while you’re adjusting. Over-exfoliating can lead to irritation, redness, and a compromised skin barrier.
And skip it entirely if your skin is already sensitive, peeling, irritated, or compromised. This isn’t a “push through the sting” situation. Glycolic acid is for healthy, intact skin that needs exfoliation, not skin that’s already angry.
The Takeaway
Glycolic acid has been a staple in skincare for decades for good reason. It can exfoliate, brighten, and smooth the skin, while also helping to improve the appearance of uneven tone, fine lines, and post-acne marks.
A seven per cent toner can be a sensible entry point for some people, but the right concentration depends on the individual and the product. Just respect the acid: start slowly, wear your SPF, and give it time to work.
