From glycolic to salicylic, exfoliating acids have quickly become a mainstay in our beauty regimes. But lactic acid seems to be the lesser-known of the bunch, despite being a dermatologist's favourite for boosting glow and hydrating skin, as well as tackling multiple skin concerns.
Naturally found in dairy products, the use of lactic acid for skin dates back to ancient Egypt, when Egyptians (including Cleopatra) famously bathed in milk to improve the look and texture of their skin. Nowadays, it’s typically created in a lab and is often combined with other do-good ingredients in serums and cleansers to deliver smoother skin results.
Here, we ask expert dermatologists to break down everything you need to know about lactic acid for skin, including where to find it and how to incorporate it into your routine.
What is lactic acid?
“Lactic acid is an alpha hydroxy acid (AHA) and versatile ingredient that can help to treat a range of skin concerns,” says Dr Derrick Phillips, CeraVe Consultant Dermatologist. A natural by-product of dairy fermentation, it’s what gives sour milk its distinctive, sharp taste.
And while we’re unlikely to bathe in sour milk any time soon, we can find lactic acid in several over-the-counter skin products, too. “In skincare, lactic acid is primarily used for its exfoliative properties and promoting skin renewal,” Dr Phillips says. “However, it can also improve skin texture, has anti-ageing benefits and has been shown to reduce pigmentation.”
@isomerskincare Replying to @twinnn #LacticAcid #ChemicalExfoliation #GlowingSkin #SkincareRoutine #SmoothSkin #ExfoliateRegularly #HealthySkinJourney #RadiantComplexion #SkincareMagic #RenewYourSkin #BrightenUp #ClearSkinGoals #YouthfulGlow #SkinRenewal #AcidToning #SkinCareEssentials #ExfoliateAndGlow #HealthySkinHabits #LacticAcidBenefits #SkinCareSecrets#lacticacidserum ♬ original sound - Isomerskincare
Lactic acid for skin: how it works
1. Exfoliates skin and promotes cell turnover
“Lactic acid disrupts the bonds between dead skin cells in the outer layer of the skin, allowing them to be shed more easily,” says Dr Phillips. All of which equals smoother skin, a more even tone and softer-looking lines.
2. Helps with breakouts and acne scars
Lactic acid accelerates skin turnover, promoting renewal. “This process not only reveals fresher and more youthful-looking skin but also helps to unclog pores, which can be beneficial for treating whiteheads, blackheads and acne pimples,” Dr Phillips notes.
@._taramd Lactic acid for Skin of Color: ✨Lactic acid is one of the least irritating AHA (ie compared to glycolic acid) and is great for those with dry sensitive skin ✨Lactic acid is a humectant, helps@ with hydration ✨It is a gentle exfoliant and with consistent use can lead to brighter completion, smoother texture and improve pigmentation ✨It’s also antimicrobial which means it great for acne! So if you find other acid too irritating for your skin type, maybe try lactic acid instead! Drop your favorite lactic acid products in the comments! #dermatologist #dermtok #texturedskin #exfoliate #hyperpigmentation #lacticacid ♬ original sound - taraMD | skin doc 👩🏿⚕️
3. Boosts hydration
Lactic acid is also a powerful humectant, meaning it helps to attract and draw moisture into the skin to keep it hydrated.
4. Supports the skin barrier
“Lactic acid has been shown to enhance the skin barrier function by increasing the production of ceramides, which help to maintain a waterproof skin barrier, reducing loss of moisture from the skin,” says Dr Phillips.
@dermarkologist What you should know about Lactic Acid #dermatologist #skincaretips #lacticacid #AHA #antiagingskincare #dryskincare ♬ Sail - AWOLNATION
5. Stimulates the production of collagen
“Additionally, lactic acid can stimulate the production of collagen and structural molecules called glycosaminoglycans (GAGS), resulting in firmer and plumper skin with fewer fine lines and wrinkles,” he adds.
6. Fade signs of discolouration
Dark spots and patches of uneven skin tone are the result of your skin cells producing excess pigment. Triggers include sun exposure, hormonal changes, inflammation and acne scars. According to Paula Begoun, founder of Paula's Choice, concentrations of 5-12% lactic acid help to fade signs of discolouration by speeding up the shedding and renewal of these cells on the skin's surface.
@dermatologysurgeon The ONE product I wish more people knew about A dark neck could be a sign of diabetes or PCOS, so it is always important to have it evaluated by your doctor. Always wear sunscreen on your skin & lips in AM when using lactic acid #lacticacid #skincarehacks #skintok ♬ original sound - Dr. Neera, Skin Surgeon
Can you use lactic acid every day?
“Lactic acid can be used daily; however, if you are experiencing dryness, redness or irritation, you will need to use smaller quantities or use it less frequently,” says consultant dermatologist Dr Magnus Lynch.
Also, take note of what other ingredients you're using and "avoid using multiple exfoliating acids [such as salicylic acid and glycolic acid] in the same routine as lactic acid unless they have been formulated to work together,” says Dr Phillips.
@annietamaki Some DO's & DON'Ts for Lactic Acid - one of my favorite & underrated AHAs! Lactic Acid is an AHA on the gentler side so if exfoliants like Retinol or Glycolic Acid irritated your skin or if you have sensitive skin, Lactic Acid is a great alternative. The most unique aspect of Lactic Acid is that it's also considered a humectant since its molecular structure can attract and bind water molecules which hydrates the skin. I love using Lactic Acid when I do want to exfoliate my skin but my skin barrier is feeling sensitive or not wanting anything too strong. OTC Lactic Acid ranges from 5-10% so choose your strength based on how your sensitive your skin is. Let me know which ingredient I should do a DO's & DON'Ts for next 👀 #lacticacid #skincare101 #chemicalexfoliant #exfoliant #skincare @Paula’s Choice @The Ordinary @Sunday Riley @Shani Darden Skincare @Peach & Lily ♬ Mouse click sound - moromi
What’s the best way to use lactic acid for skin?
Available in cleansers, exfoliators, serums and creams, lactic acid can easily be incorporated into your daily skincare routine. For lactic acid first-timers, seek out a product with a low strength (around 5% - 10%) and slowly work your way up. Start by using it one to three times a week to build tolerance and increase frequency only if there is zero redness or irritation.
All-importantly, "make sure to use a sunscreen during the day as lactic acid can make your skin more sensitive to the sun,” says Dr Lynch.
As a cleanser: “I would recommend starting with a cleanser containing lactic acid and using it in the evening,” suggests Dr Lynch. “Follow with a nourishing moisturiser afterwards."
As an exfoliator: A lactic acid exfoliator comes in the form of either a peel treatment, scrub or toner, so it's important to follow the instructions on each individual product. Some toners and treatments are gentle enough to use every day; others with a higher percentage of lactic acid should typically be applied to clean, dry skin with a cotton pad a couple of times a week, always avoiding the eye area.
If recommended by the brand, you may also like to dilute a lactic acid resurfacing treatment with other serums to reduce the strength until your skin develops tolerance.
As a serum: Serums are also a targeted way to introduce lactic acid into your skincare. Like any active ingredient, there are certain considerations when combining it with other serums and creams.
“Both lactic acid and retinoids are potent exfoliants, so it's a good idea to introduce them into your skincare routine gradually and to not apply them on the same day to minimise the risk of irritation,” says Dr Phillips. The same rule applies to using spot-fighting benzoyl peroxide.
@sparklesandskin Reply to @queeneeyy556 #LacticAcid How to use it? 🤔 #theordinary #exfoliate ♬ original sound - sparklesandskin
Side effects of lactic acid
Generally speaking, “lactic acid is gentle when compared to other exfoliants – meaning it can be used regularly without irritating the skin,” notes Dr Lynch. In fact, it is the gentlest of alpha hydroxy acids. With that said, “if used excessively, it could irritate sensitive skin, causing redness, dryness or irritation.”
If you do have very sensitive skin, it may be best to steer clear of lactic acid. Our advice? Try a product with a very low percentage of lactic acid and see how your skin gets on with it. If you notice severe tingling and redness, wash it off straight away (know that a little tingling is normal).
Originally published on Glamour UK.