Spotlight on... GLYCOLIC ACID

Glycolic acid is a common skincare ingredient used in both in-salon treatments and homecare routines. Ellen Cummings speaks to the skincare experts about how it works, the concerns it can treat and the active ingredients it can be used alongside

How does glycolic acid work?

Glycolic acid is an alpha hydroxy acid, or AHA, that’s naturally derived from sugarcane. However, it’s common for skincare formulas to contain a bio-identical molecule created in a lab rather than the naturally derived version.

As a chemical exfoliant, glycolic acid breaks down the bonds of the stratum corneum. Gina Baker, skincare expert and trainer at Germaine de Capuccini, explains, “Skin cells are held together by positive and negative ionic charges. Glycolic acid can cancel some of that charge, which weakens bonds and loosens skin cells.”

This helps to separate and dissolve the desmosomes (a kind of protein) which are the bonds that hold keratinocytes (old skin cells) together, explains Evans, adding, “This will speed up cell turnover.”

As well as brightening skin on the surface, it can also work on a deeper level. “Glycolic acid has the lowest molecular weight of all the acids,” says Maria Naskos, national educator for Xpert Professional, which distributes skincare brand Dibi Milano. “This means it is small enough to penetrate the stratum corneum to travel into the deeper layers of the dermis, and can even make its way into hair follicles. Once in the hair follicle, the glycolic acid creates a process of desquamation and chemical exfoliation.”

These actions mean it is great for supporting hydration, minimising lines and pores, reducing hyperpigmentation and fighting acne.

How should it be used?

Glycolic acid is particularly good in treatments focused on helping clients to achieve glowing skin. Naskos says, “A glycolic acid stimulator peel with a lower pH will act as an effective exfoliator to brighten and enhance skin without downtime. It can also be used in a higher percentage as a chemical peel.”

Baker says this type of peel is ideal as a bolt-on in many facials, “particularly where product absorption is key”, adding, “It’s also a great treatment in a deep-cleansing back therapy where congestion is a concern.”

Clients have a range of choices as to where they incorporate glycolic acid into their at-home routine, but it’s important that therapists educate them. Naskos explains, “Because it’s a very small molecule, it’s rather fast acting – therefore, clients should introduce it gradually to build up tolerance and avoid irritation.”

“GLYCOLIC acid, also known as HYDROACETIC acid or HYDROXYACETIC acid, is a 2-hydroxy mono-carboxylic acid – that is, ACETIC ACID with a HYDROXYLATED methyl group„

What can you pair it with?

Although people may have strict rules about combining active ingredients, it depends on each individual’s skin, the concerns they want to target and how they apply products.

Baker explains, “Vitamin C and glycolic acid work extremely well together but sadly it’s often frowned upon. The key here is to minimise irritation by applying vitamin C in the morning and glycolic at night. Both will reinforce collagen production without overstimulating skin.

Meanwhile, Evans advises that “other acids and retinoid use may need to be tempered to avoid skin sensitivity”.

One ingredient that works well with glycolic acid with minimal risk of sensitisation is hydration hero hyaluronic acid. Deborah Carrington, skincare expert at +maskology, says, “A product that is enriched with hyaluronic acid used after the exfoliating effects of glycolic acid will absorb quickly and effectively into the skin.”

As with any skincare, the most important pairing is SPF. “Glycolic acid does make the skin more photosensitive,” says Baker. “It’s imperative that the client is given the correct aftercare advice. Ensure the salon is stocked with a high-quality SPF50 that also protects from blue light and pollution.”

Are there any contraindications?

The fast-acting nature of glycolic acid means it can be sensitising, but the risk depends on the percentage. “In most consumer skincare products, you’re unlikely to find a concentration of any AHA, including glycolic acid, above 10%,” says Naskos. “This is generally safe for skin – anything higher is usually only used by skincare or medical professionals. However, any concentration above 12% is not safe for use during pregnancy or breastfeeding.”

Clients with sensitive skin may be extra prone to reactions, so might be better suited to an acid with a larger molecule size. For those with temporary lifestyle factors that increase sensitivity, such as a recent depilation, Baker recommends avoiding glycolic acid altogether.