Glycolic Acid: How to use it for skin benefits

MECCApedia is here to decode the science, unravel the jargon and give you the knowledge to understand the actives you're slathering on morning and night. Let your skincare education commence!

Our skin has its own natural exfoliating mechanism, but like most things in life, this process slows down as we age, leaving skin susceptible to a build-up of dulling surface skin cells. Regular exfoliation can complement this cellular turnover process for skin that’s smoother and brighter-looking. One of dermatologists’ favourite exfoliators? Glycolic acid. 

Part of the alpha hydroxy acid family of chemical exfoliants, glycolic acid works on two levels. First, on the surface of the skin, where it will gently loosen and slough off dead skin cells to help refine the complexion, literally clearing the path for all other products to do their thing . The second is helping the skin to feel firmer. But glycolic acid is not just here to deliver exfoliation benefits – this clever ingredient can also help hydrate skin, too. Read on to find out how.

Glycolic acid is an alpha-hydroxy acid (AHA) that's derived from sugarcane. You may have heard of other AHAs, like lactic acid and citric acid, but glycolic acid is the smallest and has the lowest molecular weight of all the AHAs, which means it can do some seriously good work.

Glycolic acid works by exfoliating the skin. It does this by dissolving the bonds between the outermost layer of skin and the next ‘fresh’ layer. This loosens the ‘glue’ that can hold dead skin cells together and in turn makes them easier to slough off.

For starters, one of the biggest benefits of glycolic acid is skin that’s smoother and more refined.

But it's not just about the surface benefits. While glycolic acid encourages skin to look and feel firmer and plumper, in addition to being an AHA, glycolic acid is also a humectant. In non-science speak, please? That means it helps to draw and retain water in the skin. So unlike some exfoliating ingredients that can leave skin dry and flaky, glycolic acid delivers exfoliation and plumping benefits. How’s that for a double score?

Glycolic acid is generally suitable for most skin types. It's recommended for those with normal, dry or combination skin who are concerned about the appearance of dark spots, dullness, or fine lines and wrinkles. It’s also a suitable option for those with oily and blemish-prone skin, as it clears skin of the stuff that might congest pores (dead skin cells, excess oil), but won't over-dry skin like some other spot products can (because, remember, glycolic acid is also a humectant).

Steer clear of glycolic acid if you’ve got sensitive skin, or excessively dry skin, as glycolic acid’s humectant mechanism means it pulls water to the surface layers, which could spell long term problems for this particular skin type.

There are lots of glycolic acid skincare products, from wash-off cleansers and masks to leave-on toners and serums, or treatment products like peel pads and spot treatments.

Your best bet is to patch test first, and if there’s no reaction, start with a low-concentration of glycolic acid (under 10 per cent) in a wash-off product, maybe one that's formulated alongside a hydrating ingredient. Use it once or twice a week to gauge how well your skin tolerates it and, if you feel ok, you can then proceed to leave-on products and higher concentrations used more regularly (but never on consecutive days – allow at least one day in between each use).

And don’t just stop at your face! Glycolic acid can also be used in body washes and lotions for baby-soft limbs. Regardless whether you’re using it on your face or body, there are three important things to keep in mind.

First, those with darker skin tones will want to proceed with extra caution, as glycolic acid can sometimes lead to irritation and uneven skin tone or dark spots.

Second, more is not more with glycolic acid. Over-exfoliate and you won't just dry out your skin, you also run the risk of leaving it appearing red and irritated. Just one glycolic product in your routine is plenty, and be sure to follow product instructions which will tell you how often to use it (this will depend on the strength and formulation) and when (usually at night as acids tend to make skin extra sensitive to sunlight).

Which leads us to the third point: it is absolutely crucial that you wear sunscreen every single day (but you're already doing that, right?). If you're using any type of exfoliating product, including glycolic acid, your skin will be more sensitive to sunlight.

Use glycolic acid alongside hydrating and nourishing ingredients, like hyaluronic acid, ceramides and glycerin. It’s also sometimes formulated alongside other chemically exfoliating acids like salicylic acid, which means it’s fine to use, but we don’t recommend attempting to mix these products together.

Don't use glycolic acid with any mechanical exfoliators, like scrubs, and definitely not with certain active ingredients including retinol or vitamin C. It's a recipe for a red-faced disaster.