Skin School - Everything You Need To Know about Glycolic Acid

Glycolic acid is a chemical exfoliating ingredient derived from sugar cane. It is part of the alpha hydroxy acid (AHA) family, which also includes other well-known acid ingredients, such as lactic acid.

Glycolic acid has the smallest molecules of all AHAs, enabling it to penetrate the upper layers of the skin effectively. This however, means more sensitive types may find its resurfacing effects harder to tolerate because of its fast absorption rate, due to its small molecular structure, as this can cause mild heat and a tingling sensation on absorption.

G.A. helps brighten skin and clear complexions, so brands are using it in everything from face washes to serums. But, as with all things in skincare, more doesn't always mean better. While the exfoliating, brightening, pigment-fading powers of this hard-working resurfacing compound are indeed formidable, incorrect or overzealous use of glycolic acid can wreak havoc with your skin barrier.

Here, I break down everything you should know about glycolic acid.

What does glycolic acid do?

Glycolic acid, like other AHA’s, acts on the surface layer of the skin, loosening and dissolving the ‘cement’ between dead cells. Think of it as dissolving the mortar between bricks on a brick wall. It therefore gently resurfaces the skin without the need for scrubbing. This is why acid-based products are often referred to as ‘chemical exfoliators’, in contrast to traditional, grit-based ‘physical exfoliators’, which are now regarded as the inferior option due to their often abrasive scratchy nature.

AHAs are water-soluble, so they work well on the superficial skin layers, which we call the epidermis. Glycolic acid has been shown in studies to have dermal influence, boosting collagen-remodelling cells (which helps to reduce the appearance of fine lines and wrinkles), and melanocyte-stabilising properties, meaning it works well for pigmentation too.

As they get to work, you often feel a tingle in the skin, which is when the desmosome (the glue-like substance which holds old skin cells together) is broken down. The skin then naturally sheds its old, dead skin cells. So, although you won’t see your skin exfoliating, you’ll soon see and feel the smoother textured, more radiant-looking skin.

Can you overuse glycolic acid?

Over-exfoliation is a big issue. Many of the skin conditions that I see and treat in the clinic are self-inflicted because of this. So many people are obliterating their skin barriers with exfoliating cleansers, followed by exfoliating acid toners, acid serums, grains and scrubs in an attempt to create flawless tone and texture, but sadly this type of product strategy tends to make skin worse because they have completely stripped their skin barrier.

Must have at home Glycolic Acid

I’d suggest a product like the MEDIK8 SLEEP GLYCOLIC which is an overnight face mask at 10%. This is quite a punchy percentage, but an effective mild alternative to a chemical peel at home for a once a week option. If you want to try Glycolic Acid but are not sure if it's the correct product for you, I adopt this method - If a product stings or hurts, it's probably not doing your skin much good.

A mild tingling or slight flushing is fine, but pain is a sign something is wrong. Similarly, using your glycolic product sparingly will achieve excellent results.

How to use Glycolic Acid

If it's a low dose, more regular use is fine, such as the MEDIK8 BALANCE MOISTURISER for oily and blemish-prone skin, or if it's a high percentage (around 10%) then once a week is enough. If you are using Glycolic Acid regularly, I'd recommend applying a moisturising product afterwards. I love the MEDIK8 ULTIMATE RECOVERY BIO_CELLULOSE MASKS, but they are expensive!

A cheaper alternative is the new MEDIK8 TOTAL MOISTURE DAILY FACIAL CREAM. Both are nourishing and calming with high levels of hyaluronic acid to hydrate after the use of a high-strength acid. Try incorporating your chosen product into your routine once a week initially, to monitor how your skin reacts, and always use sunscreen in the daytime (as acids can increase skin sensitivity to sunlight).

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