We earn a commission for products purchased through some links in this article.
#SkinSchool: Lactic acid explained
For more sensitive skin types, lactic is the glow-granting alpha hydroxy acid you need to know about
When thinking about alpha hydroxy acids, otherwise known as AHAs, glycolic acid might first come to mind – or to hand, in one of your skincare products. But the lesser-used lactic acid might actually be what your skin is crying out for.
“Lactic acid is a water-soluble alpha hydroxy acid that exfoliates the surface of the skin to reveal a smoother, brighter complexion,” explains Shani Darden, one of Hollywood’s favourite facialists and formulator of her eponymous skincare line.
Like other AHAs such as glycolic, mandelic, and citric, lactic acid can be found in a variety of skincare products from toners to exfoliators and serums. It’s how the ingredient differs to the others that dictates what – and who – it's best for.
How is lactic acid different to other AHAs?
“The lactic acid molecule is larger than other AHAs like glycolic acid, or the beta hydroxy acid (BHA) salicylic acid,” explains Darden. “A larger molecule means that it cannot penetrate the skin as deeply, so you're getting more surface treatment” – think exfoliating and, ergo, brightening. This is good news for those with sensitive skin, she says, who'll likely be able to tolerate lactic acid’s resurfacing effects much better than glycolic, or even retinol, which encourages cell turnover.
“Lactic acid is also less likely than glycolic or salicylic acid to disrupt the pH of your skin,” she notes, “keeping your natural moisture barrier healthy”. So if your skin errs on the side of sensitive, or you are keen to strengthen your skin as opposed to strip it (which you should be), making lactic acid your exfoliant of choice is a wise move. “It can even add a little hydration back into the skin,” she says, given how lactic acid acts as a humectant, meaning it attracts moisture to the skin.
Is there anyone who should avoid lactic acid?
While lactic acid is suited to most skin types, Darden says some must proceed with caution. “Those with extremely sensitive or reactive skin may not be able to tolerate lactic acid or be able to use it as often as other skin types,” she cautions. “But it should typically be okay if introduced slowly to allow skin time to acclimate.”
Because of its tolerable characteristics, lactic acid is thought to be safe to use in pregnancy, too. To be careful, opt for products containing lower levels and always patch test your skin to see how it reacts, remembering that hormonal changes can have a knock-on effect on your skin's normal sensitivity levels.
What is the best way to use lactic acid in your skincare routine?
Darden recommends incorporating lactic acid into your night-time routine as your treatment product to exfoliate and brighten the skin overnight. Come morning, always remember to protect freshly exfoliated skin with SPF, especially as AHA use may increase your skin's sensitivity to the sun and the possibility of sunburn.
As with any active skincare product, it pays to play the slow and steady game when using it. “Start using lactic acid one-to-two nights a week and increase your use slowly, adding in one additional night each week,” Darden suggests. “You can build up to as often as your skin can tolerate.”
As a rule of thumb, on the days you choose to include lactic acid–or any other exfoliant–in your routine, avoid products containing vitamin C and retinol immediately after. This will allow your skin to work with a single active ingredient at a time, reducing the risk of overstimulation. Finally, avoid mixing AHAs, too, unless you choose a product that has been formulated as a combination of acids.
Below, see the best lactic acid-based skincare products as recommended by Bazaar’s beauty team.
10 of the best lactic acid products to try now:
An exfoliating cleanser is a clever way to incorporate AHAs into your routine if a treatment product intimidates. Take this offering from Ignae, which cocktails lactic, citric and tartaric acids to provide gentle exfoliation. And – for a mild peeling effect – after massaging onto your face, you can let the cleanser sit for a minute before washing away. Either way it'll leave skin moisturised, as well as refined.
With 10 per cent lactic acid, this serum accelerates cell turnover, helping to shift dullness and refine hyperpigmentation. Meanwhile the addition of squalene (sustainable brand Biossance’s core ingredient) soothes irritation and quenches dehydration. This is a brilliant option for anyone wanting a one-and-done active night-time routine after cleansing.
This smart serum combines the benefits of two key active skincare ingredients: AHA in the form of lactic acid, and vitamin C – another superior skin brightener. If fading dark spots, improving radiance and smoothing fine lines is your priority then this is one to try.
This potent “peeling solution” comes in the form of a lightweight serum. Combining lactic acid at 10 per cent, it’s hailed for its ability to improve acne scarring and hyperpigmentation, plus being enhanced with hyaluronic acid – another humectant – it helps improve the skin’s ability to attract and retain moisture. Beginners would do well to start on the five per cent version, while you can also reduce the strength by diluting the serum with other products, such as your moisturiser, until your tolerance develops.
Another stellar option is this Liquid Mask from Oskia. Combining 10 per cent lactic acid ("the Queen of all acids", according to Oskia's founder Georgie Cleeve) with tone-brightening niacinamide and mixed molecular weight hyaluronic acid, it's intensely hydrating, as much as complexion-refining. Don't only take our word for it; the overnight peel's five-star reviews all report radiant skin come morning.
This powerful yet gentle serum combines lactic acid with gluconolactone, a polyhydroxy acid (PHA) considered ‘cousins’ of AHAs. “It supports the natural cell renewal process, helping to resurface and retexturise skin with nine per cent lactic acid to boost skin’s clarity and reveal radiance,” explains Darden. Additionally, it contains green and white tea for antioxidant protection, helping to prevent premature ageing on multiple levels.
Fellow influential facialist Teresa Tarmey is another advocate for the use of lactic acid. Her signature 'TT Facial' has always incorporated lactic acid as the key exfoliator, and subsequently she formulated her own version for at-home use. The toner is gentle while effective, and does everything you want from a lactic acid product: polishing and brightening while aiding moisture retention.
Generation Glow Daily Resurfacing Essence with 5% AHA Complex Alpha-H
This gentle AHA exfoliator is dermatologist-approved for sensitive skin. The five per cent blend of AHAs features lactic as the star, alongside citric, tartaric, and malic acids which together help to even out skin tone and texture while increasing luminosity. In addition, the formula’s Australian postbiotic botanical blend is intended to bolster a healthy barrier.
For those experiencing bumpy skin on the body, known as keratosis pilaris, Ameliorate’s now-cult Transforming Body Lotion is an easy way to help smooth away this common condition. With optimum levels of lactic acid, plus urea – which also helps to loosen dead skin cells – and sweet almond oil, this rich lotion leaves skin softer and more uniform in tone.
Another active-packed body treat we rate: Dr Sam’s Flawless Body Therapy blends bakuchiol (a plant alternative to retinol) with niacinamide (a form of vitamin B3 boasting myriad skin benefits) and lactic acid. It brightens dull skin, smooths unevenness and firms crepiness.
