Glycolic acid is one of those ingredients that gets a lot of airtime. Found in everything from toners to cleansers, serums to masks, so many skincare experts and enthusiasts — the entire Stylist beauty team included — really rate its power to exfoliate, brighten and plump skin, as well as its ability to ward off congestion and blemishes. But given it is so powerful, it’s vital that you understand how, why and when to use glycolic acid, as well as the best products to find it in. 

To get you up to speed, we’ve enlisted the help of dermatologist Dr Nyla. She’s the founder and medical director of Medispa Cheshire, as well as clinics in Liverpool and on London’s Harley Street. Basically, she knows everything there is to know about skincare (her 1:1 virtual skin consultations are in high demand) so she’s very well placed to walk us through everything there is to know about glycolic acid.

From the key benefits, to the best products, consider this your glycolic acid cheat sheet.

Glycolic acid falls into the alpha-hydroxy acid (AHA) family, known for its exfoliating abilities. Glycolic is most often sourced from sugarcane and as it’s one of the smallest AHA molecules, it’s able to penetrate the skin much more deeply than other acids, making it one of the most popular skincare ingredients.

“It’s a great exfoliator, shedding dead skin at the stratum corneum level to reveal fresh, brighter, glowing skin,” explains Dr Nyla. And that’s just for starters. “It also helps with the acceleration of neocollagenesis and fibroblast stimulation, which means it makes the skin firm and tight. It can help treat hyperpigmentation in certain skin types and can suppress acne formation and reduce breakouts.”

“Glycolic acid is best for anyone and everyone with normal to oily skin types,” says Dr Nyla. “However, for those with sensitive or excessively dry skin, it can become an irritant so be warned.” 

Like many active ingredients, glycolic acid is available in different potencies. As a basic rule, the higher the percentage, the stronger the formula, so if you have sensitive skin, it’s worth sticking to the weaker end of the scale. “The optimum percentage is 10% for low impact and up to 20% for those wishing to have a deeper impact,” explains Dr Nyla.

While more potent glycolic peel or exfoliant products are best saved for once or twice a week max, those in lower concentrations can be used daily. “A cleanser or toner, used in combination with water, can be highly effective without being too irritating as glycolic acid immediately is neutralised by contact with water,” Dr Nyla reveals.

“Combining [or layering] glycolic acid with retinol can be problematic as increased cell turnover leads to increased penetration of the retinol formula, due to thinning of the stratum corneum, and that can cause irritation,” warns Dr Nyla. “However, pairing with gentle exfoliating agents such as salicylic acid is okay.”

On the flipside, “glycolic acid can be combined with vitamin C to improve pigmentation concerns and improve collagenesis,” she adds. “The combination is best used at night when cell renewal and recovery is at its peak.”

Given it’s such a brilliant exfoliant and glow-giver, you might want to extend your use of glycolic acid to your entire body. Dr Nyla is an advocate, but says, “I would recommend a low dose of around 10 percent combined with a moisturising partner such as cocoa butter or vitamin E.”

There’s many ways to include glycolic acid into your routine, and the one you choose really depends on personal preference teamed with how strong a formula you’re after. 

A glycolic acid cleanser will dissolve dirt, gently exfoliate and improve skin’s radiance and texture. “I would start off with one with a low concentration of glycolic acid,” recommends Dr Nyla. “As cleanser is on the skin very transiently, this will limit exposure and determine your skin’s affinity to glycolic acid quickly.” 

On the other hand, glycolic acid toners are great for those with oily skin. “They maintain pore sterility which means skin will be less congested, reducing spots and eliminating blackheads,” Dr Nyla explains. 

Finally, there’s glycolic acid masks. “These can be overbearing, even for those with insensitive/normal skin, as they can contain up to 30% glycolic” says Dr Nyla. “I rarely recommend these unless heavily combined with camomile or aloe vera to avoid harsh stripping.”

Whatever type of glycolic acid product you opt for, just be sure not to double up on the ingredient elsewhere. For instance, if you use a potent glycolic toner, don’t then also use a glycolic cleanser every day.

Armed with that knowledge, it’s time to find the right glycolic acid skincare product for you. Below, you’ll find the ones the Stylist beauty team really rates.

Images: Getty / courtesy of brands.