If you’re hoping to give your skin a lit-from-within glow, want cleaner pores or are looking to reduce redness, you’d better believe there’s an acid for the job. 

Glycolic acid is known for its radiance-boosting benefits, salicylic acid exfoliates and unclogs pores, azelaic acid targets redness and breakouts, and there are even some lesser-known acids, such as antioxidant-rich phytic acid, that are gradually finding their way into our daily skincare routines. 

But if you’re looking for an acid that is much gentler on skin, you’ll be pleased to hear that there’s a low-intensity ingredient out there that boasts some incredible skin benefits: lactic acid.

Derived from a more unconventional place, it’s a substance found in milk. You might recognise it because it’s often found alongside other ingredients, often to maximise the alpha hydroxy acid (AHA) blend, but it’s now slowly growing in popularity as a trusty exfoliator in its own right.

But how exactly can lactic acid help you and your skin? To find out, we spoke to Lisa Kordecki, head therapist at beauty skincare provider SkinCity, to find out more.

What is lactic acid?

“Lactic acid belongs to the family of alpha hydroxy acids (AHAs),” says Kordecki. “It’s found in dairy products, and it’s what gives yoghurt and soured milk that distinctive tang.” However, while some people do still take milk baths, most of the lactic acid found in skincare products today is synthetically produced. “Lactic acid is seen by many as the gentler, more tolerated alternative to glycolic acid due to its slightly bigger molecule size.”  

What are the benefits of lactic acid in skincare?

Typical of an AHA, lactic acid is an exfoliant that speeds up cell turnover and stimulates cell renewal to help even out skin texture, fade hyperpigmentation and smooth fine lines. “However, lactic acid has an extra benefit you won’t get from its AHA cousins,” adds Kordecki. “It’s a powerful humectant, helping improve the skin’s natural moisture barrier and hydration levels. This makes it ideal for dry or sensitive skin, alongside being a safe and effective ingredient for darker skin types, too.”

Which skin types and concerns suit lactic acid the best?

Lactic acid works on all skin types, but it’s particularly beneficial for sensitive, dry and mature skin. “It should be one of the first exfoliating acids people go to if they are more sensitive or cautious about exfoliating. It’s been proven to help hyperpigmentation (ie sun spots or age spots) fade and is safe for use on darker skin without the worry of post-inflammatory hyperpigmentation,” she says.

It also works effectively on body skin. “In recent years, it has been proven to help dislodge and remove the keratin plugs from the hair follicles for anyone who has keratosis pilaris (also often referred to as ‘chicken skin’), thanks to its ability to help dissolve dead cells that build up, which then helps to gently smooth the skin.”

What’s the best way to use lactic acid in a skincare routine?

For a gentle daily brightening effect, using moisturising creams and serums is best. However, as lactic acid speeds up cell turnover, it can make skin more vulnerable to UV damage so it’s best to apply products at night to minimise potential sun damage. “However, you’ll need to use your SPF every morning to protect skin, and if you notice daily use is causing irritation, scale it back to a couple of times per week maximum.”

For stronger exfoliation, try using a mask or at-home peel once or twice a week. “Start with a low-strength product and, if your skin responds well, begin to work up to higher strengths if needed. Be careful not to over-exfoliate – and that includes using other AHAs, BHAs and topical retinoids – otherwise you’ll over-sensitise your skin,” says Kordecki. 

How to make the most of lactic acid-based skincare products?

It takes around 28 days for the skin’s natural exfoliation cycle to finish, a process known as desquamation. While chemical exfoliants, like lactic acid, will aid the process, it still takes time. “The most important thing is to choose a formulation designed for your skin type, skin condition and preferred routine,” says Kordecki. For example, if you prefer to use an active ingredient in a cleanser rather than a peel, and vice versa, stick to that. “Other hydrating ingredients, like hyaluronic acid, work well with lactic acid, as both have humectant properties to keep your skin hydrated and plump,” she adds.

So, if you’re now considering becoming a lactic acid convert, we’ve rounded up the best products that implement it as either a lead ingredient or in combination with other effective acids. 

Images: Getty; courtesy of brands