Glycolic acid is the hero ingredient you may not know you needed. Brilliant at brightening skin tone and texture, as well as reducing the appearance of fine lines, wrinkles, breakouts and blemishes, it really is a routine must-have. But that doesn’t mean you can just throw it in anywhere; given that it’s an active ingredient, a little bit of homework is required before you introduce it into your regime. Here’s what you need to know.
What is glycolic acid?
Glycolic acid is a chemical exfoliant that belongs to a family of acids known as alpha hydroxy acids, or AHAs–a term you’ve probably heard being bandied about in skincare circles. Widely used and derived from sugar cane, other AHAs include lactic, citric and mandelic acids. “It is found in many skincare products like face washes and serums, in mild strengths, but is often used in stronger formulations by professionals as a skin peel,” says beauty specialist Nilam Holmes.
What does glycolic acid do to your skin?
Glycolic acid is a powerhouse ingredient with so many skin benefits. “It’s the ultimate exfoliator,” explains skin expert Keren Bartov. Loosening the glue that holds dead cells to the skin’s outer surface, the stratum corneum, glycolic acid helps to reveal the younger, fresher cells underneath. “Furthermore, because it has the smallest molecular structure of all AHAs, it can penetrate deeper and faster into the skin than other acids,” adds Bartov. Thanks to this ability to penetrate the dermis–the layer of skin beneath the epidermis where collagen is secreted by fibroblast cells–it helps promote collagen synthesis, too.
It’s also fantastic for treating breakouts. “Glycolic is great for anyone who is suffering with breakouts,” says facialist Teresa Tarmey. “I find salicylic drying, which can then create another problem.”
Is it OK to use glycolic acid every day?
As with any acid, overuse or combining it with other harsh acids can lead to skin irritation. “Using glycolic acid in high strengths too frequently can lead to over-exfoliation which can destroy the skin’s protective barrier,” says Holmes. “That said, it can be used every day in mild strengths. It really depends on the formula.”
If your skin becomes sensitive, shows signs of redness or flaking, or, if it feels fragile, stop use. “The protective invisible shield which protects our skin from daily pathogen attack could have been breached,” says Diane Ackers, specialist at Doctors Formula. “If the skin looks ultra-smooth, almost waxy in appearance, this is often the first sign that you’re using too many acids.”
If in doubt, start with the lowest concentration of acid, use it every two to three days and gradually increase your frequency of use and strength of acid as your skin adjusts.
Is glycolic acid suitable for all skin types?
Glycolic acid is effective when used on normal, combination and oily skin, but sensitive skins should be wary of diving straight in, as it can cause irritation. “If your skin is sensitive or prone to irritation, then glycolic acid may cause a reaction like dryness, redness and create more sensitivity,” says Bartov. Just as you’d use retinol sparingly to start with, exercise caution when it comes to trying glycolic for the first time.
Seasonality can also impact how well it’s tolerated. “As [glycolic acid] is effectively stripping away the upper layers of skin cells, it can make your skin more sensitive to sunshine; using sunscreen is therefore essential,” warns Dr Anjali Mahto. Happily, for those trying to navigate the confusing world of pregnancy-safe skincare, glycolic acid (in low concentrations) is on the accepted list of ingredients to use – particularly welcome news if you’re experiencing hormonal dullness or breakouts.
Those with darker skin types may want to approach with caution. “I’ve found higher strength products can actually create a burn on darker skin types as it changes the PH of the skin,” says Tarmey. “This is more to do with in-clinic products as opposed to at-home ones.” If you do find yourself unable to tolerate it, for whatever reason, you may want to try lactic acid as an alternative.
What’s the best form of glycolic acid to use?
If you’re new to this AHA, an easy way to incorporate it into your routine is through a cleanser, which won’t come into contact with skin for too long and is quickly washed off. It’s also a good litmus test for sensitivity as glycolic acid is immediately neutralised on contact with water. Once you’ve acclimatised you can move on to leave-on formulations including toners, serums and moisturisers, where concentration will be a little higher.
While products like cleansers and toners that contain small amounts can be used daily, most people find once or twice a week is sufficient when using anything stronger. The ideal concentration is somewhere between 8 to 15 per cent. Higher concentrations of glycolic acid will naturally yield more intensive results and offer an instant skin glow, but these should only be used by professionals. As well as the concentration, pay attention to the pH of your chosen product; those formulated with a higher pH are done so in order to weaken the acid’s strength, and therefore minimise potential irritation to the skin. If the pH of your product sits between three and four then it is guaranteed that the strength of glycolic is as it is stated on the bottle.
What are the disadvantages of glycolic acid on skin?
Although it can be used seamlessly with other AHAs and BHAs, including pore-refining salicylic acid, there are some standout skincare ingredients that should be avoided while you use glycolic such as retinoids. If you’re desperate to reap the skin-boosting benefits of both, start using one and work up your tolerance gradually. Once you’ve established that, introduce the other slowly and only use them on alternate days. The two used together at the same time is a recipe for serious irritation, no matter how robust you think your skin is.
Although it’s a gentle exfoliant, as with anything active, overuse can cause damage, particularly to the skin barrier, the skin’s first line of defence against harmful pollutants and pathogens. “Using glycolic acid too frequently or in high concentrations can lead to over-exfoliation and strip the skin of its natural oils, damaging the skin barrier and leading to irritation, sensitivity, dryness, redness, flakiness, and breakouts,” says Holmes. “Overuse can also make the skin more susceptible to sun damage.”
In the winter months particularly, the skin barrier is often compromised by colder temperatures and fluctuating central heating anyway, so avoid being too overzealous with your glycolic, especially if trying it for the first time. If you have overdone it, you’re likely to experience dryness, flakiness, redness and irritation. Slow and steady wins this race,” says Bartov. “Or you’re risking damaging the skin’s barrier and inviting in sensitivity, irritation, and inflammation.”
The best glycolic acid products to try
Drunk Elephant T.L.C. Framboos Glycolic Night Serum
The Inkey List Glycolic Acid Toner
Sunday Riley Good Genes Glycolic Acid Treatment
Alpha-H Liquid Gold Exfoliating Treatment with 5% Glycolic Acid
Neostrata Foaming Glycolic Wash
Skinceuticals Glycolic 10 Renew Overnight Cream
Murad Vita-C Glycolic Brightening Serum
Medik8 Sleep Glycolic Serum
Dr Dennis Gross Alpha Beta Peel Extra Strength Formula
Ren Glycol Lactic Radiance Renewal Mask
Kiehl’s Ultra Pure High-Potency Serum 9.8% Glycolic Acid
This story originally appeared in British Vogue.