Lactic Acid: The Gentle, Hydrating Exfoliator Adored By Experts And Sensitive Skin-Sufferers Alike

Acid exfoliators come in wide varieties and strengths—some are quite intense and need to be incorporated into your routine slowly (glycolic acid, I’m looking at you) and others are gentle enough to be used on the most sensitive skin types. Ultimately, though, they all have the same goal: to slough away dead skin cells and reveal the brighter, smoother skin that lies beneath.

As someone with pretty sensitive, acne-prone skin, I’ve always been most drawn to lactic acid. Not only is it one of the gentler AHAs on the market (meaning it doesn’t make my skin break out or flare up), but it also has a hydrating effect, which makes my skin positively glow every time I use it.

And it’s not just for the face, either. As one of the gentler chemical exfoliators, lactic acid is also great for the body—providing a subtle yet effective way to exfoliate and hydrate skin conditions like keratosis pilaris without irritating sensitive skin or causing further flare-ups.

But what actually is lactic acid? What’s the best way to incorporate it into your routine? And crucially, with so many lactic acid-based serums, cleansers, and essences to choose from, which products are actually worth investing in? If you’re looking for an in-depth guide on lactic acid, you’ve come to the right place. I asked Consultant Dermatologists Dr Derrick Phillips and Dr Aiza Jamil for their expert insights on this widely used skincare ingredient.

What is Lactic Acid?

“Lactic acid is a gentle alpha hydroxy acid (AHA) derived from the fermentation of lactose found in milk, and it’s a widely used ingredient in skincare”, says Dr Phillips. "It’s a versatile ingredient that can help address a range of skin concerns but is particularly well known for its ability to encourage cellular turnover, helping to improve overall skin texture and radiance”. Despite its name, Dr Jamil assures me that most versions used within skincare are synthetic and vegan-friendly. “It is one of the most gentle chemical exfoliants”, she says.

So what’s the science behind it? “Lactic acid works by disrupting the bonds between dead skin cells in the outer layer of the skin, allowing them to be shed more easily”, explains Dr Phillips. "This process helps to reveal fresher, more radiant-looking skin, while also supporting clearer pores by reducing the build-up of dead skin cells on the surface.” Dr Jamil continues: “Compared to other, stronger AHAs such as glycolic acid, lactic acid is a larger molecule, so it penetrates more slowly and can be less irritating on the skin. It can improve skin texture and brightness, and can help to fade hyperpigmentation and dullness."

One thing I adore about lactic acid is how hydrating it is, making my skin feel drenched with water without feeling at all heavy or oily. Dr Phillips explains that this is because lactic acid also acts as a humectant, drawing water into the skin and supporting hydration alongside exfoliation. “As part of the skin’s natural moisturising factors, it helps to maintain moisture levels and keep the skin feeling soft and supple,” he tells me. “Regular use can help to improve overall skin texture, support a more even skin tone and reduce the appearance of pigmentation”.

What skin type is lactic acid best suited to?

Lactic acid hydrates while it gently softens, making it perfect for those with the notoriously hard-to-deal-with combination of dry and sensitive skin. Our experts both pointed out that it’s also great for those looking to address dullness, fine lines, uneven skin tone, and mild hyperpigmentation. But while it’s been hailed as an exfoliation saviour for sensitive skin, Dr Jamil still advises caution for those with a compromised skin barrier or active or inflamed acne: “I would recommend staying away from any acids, as although lactic acid is gentler in comparison to others, it may still be too aggressive or exfoliating”, she says.

How to incorporate lactic acid into your skincare regime

It’s hard to find a product that lactic acid can’t be used in—from cleansers and essences to serums and moisturisers. Dr Phillips tells me this hero ingredient can be incorporated into a routine in several ways, but as with any active ingredient, it’s best introduced gradually and used alongside a simple, barrier-supportive routine.

“Starting with a cleanser containing lactic acid offers a gentle way to exfoliate the skin and keep pores clear, without disrupting the skin barrier,” he says, but using a serum is often the most effective approach. "As it allows you to take advantage of both the exfoliating and hydrating properties of lactic acid in a more targeted way”.

It pairs exceptionally well with other actives, allowing you to get maximum skincare benefits from minimal products. As an example: “In the Genaura Levagen+ Smart Face Serum, lactic acid is combined with ingredients such as palmitoylethanolamide, niacinamide and panthenol,” says Dr Phillips. “This allows you to pair gentle exfoliation with barrier support and anti-inflammatory benefits, helping to improve overall skin texture, hydration and tone."

Dr Jamil points out that due to their exfoliating effects, it’s best to use any acid as part of your nighttime routine, after your cleanser and before your moisturiser (if using it as a serum). She also stresses the importance of introducing the ingredient gradually. “I would begin integrating it at two to three times per week at a lower concentration of around 5 to 10%," she says. “I would avoid layering with strong retinoids or other acids, as this can be too aggressive on the skin.” She also points out that AHAs increase sun sensitivity, so it’s important to always wear a high-factor SPF during the day.

How can lactic acid be used on the body?

The skinification of bodycare has really taken hold, and using ingredients like lactic acid can really boost the efficacy of our body creams, cleansers and serums. Dr Jamil tells me that lactic acid in body care can be particularly helpful for those who experience dry patches, rough or bumpy skin, keratosis pilaris, or ingrown hairs (goodbye uncomfortable bikini line).

So what lactic acid bodycare products should we look out for? “You can find body lotions or serums that have lactic acid in them, usually at around 10 to 12%," says Dr Jamil. "These can be used every other day to begin with and then worked up to every day if needed, as the skin on your body is tougher than the skin on your face." So the smoothing, hydrating effects of lactic acid can be extended to my entire body? Stunning.