The Benefits of Lactic Acid for Skin Go Beyond Exfoliation

Putting acid on your face might sound like a recipe for disastrous stinging, burning, and peeling—a la Samantha’s lobster-red face in that unforgettable episode of Sex and the City. Lactic acid for your skin, however, is anything but harsh. It’s one of the least irritating actives around, in fact. And it’s friendly to nearly all skin types.

Along with its gentle nature, it’s also pretty powerful and effective. And the experts we consulted assured us that the standout chemical exfoliant also offers some unique benefits that its counterparts don’t.

To give you a full picture of everything this versatile ingredient has to offer, we asked dermatologists to explain what lactic acid is, what kinds of skin care benefits it can deliver, and some of the best ways to work it into your regular routine (expert-approved product picks included).

What is lactic acid?

“Lactic acid is an alpha-hydroxy acid that comes from the fermentation of lactose, a sugar naturally found in milk,” Margarita Lolis, MD, a board-certified dermatologist at Schweiger Dermatology Group in New Jersey, tells SELF. (Don’t worry, the kind used in skin care products is typically synthetically derived, and not from sour milk.)¹

As a quick reminder: The majority of skin care acids fall into one of three categories: alpha-hydroxy acids (AHAs), beta-hydroxy acids (BHAs), and poly-hydroxy acids (PHAs), which differ based on their chemical composition and benefits. Compared to its AHA buddies, lactic acid is one of the least irritating, Dr. Lolis notes.² This is largely because it doesn’t sink as deeply into the skin.²

For example, glycolic acid (another popular alpha-hydroxy acid) is a smaller molecule that penetrates deeper and faster into the skin, Jeannette Graf, MD, a board-certified dermatologist and assistant clinical professor at Mount Sinai School of Medicine in New York City, tells SELF. And that ups the likelihood of irritation.²

What can lactic acid do for your skin?

As we touched on above, the primary benefit of any alpha-hydroxy acid is exfoliation, although lactic acid is somewhat of an overachiever and goes above and beyond that standard job description.

Lactic acid gently exfoliates.

“Lactic acid works by loosening the ‘glue’ that holds skin cells together, encouraging exfoliation of the dead skin cells and increasing cell turnover,” Dr. Lolis explains.¹ And that can lead to a whole host of benefits, including a brighter complexion, reduced hyperpigmentation and dark spots, a smoother texture, and unclogged pores. And the fact that it can do all of that without causing irritation (a common issue with more potent ingredients) makes it ideal for folks with dry or sensitive skin.

However, both of the dermatologists that SELF spoke with call out that higher concentrations will be more intense. For example, most over-the-counter at-home products have a lactic acid concentration of 10% or less, says Dr. Lolis. When the ingredient is used for in-office chemical peels, that percentage is typically higher. Research shows that at 12%, for example, it can penetrate deeper into the dermis (the middle skin layer), potentially minimizing the appearance of fine lines and wrinkles.³ (Although, it’s best to talk to a dermatologist before getting any sort of chemical peel to avoid a skin freakout—especially if you have sensitive skin)

It’s also hydrating.

Here’s where things get interesting. Typically, exfoliating and moisturizing ingredients are two different things, right? That’s not the case with lactic acid. Along with being an exfoliant, it’s also a humectant, meaning it attracts water for a hydrating and plumping effect, Dr. Graf points out. (Hyaluronic acid is also a popular humectant, FYI.) That’s another reason why it’s so well-tolerated: Its moisturizing properties help to combat any potential dehydration from the exfoliation, notes Dr. Lolis. This makes it an especially great pick if you’re dealing with dullness, dry skin, and flaking.

It has antimicrobial properties.

According to Dr. Lolis, lactic acid also has antimicrobial properties. This means that it kills pathogens like bacteria.⁴ That’s important because it can help create a balanced microbiome (the combination of billions of microorganisms) on the surface of your skin. The result? Less inflammation and a stronger, healthier skin barrier—which can also mean less dryness, Dr. Lolis adds.⁵

To that point, you may also think lactic acid is a good choice for fighting acne—and it’s definitely not a bad one. After all, it can help clear out clogged pores without drying the skin, and that’s always a win when you’re battling blemishes. However, both of the derms we spoke with note that, on its own, lactic acid really isn’t the best acne treatment. That job is a better fit for beta-hydroxy acids, like salicylic acid (which can break down oil and combat inflammation), and ingredients that can kill acne-causing P. acnes bacteria, like benzoyl peroxide.^{6 7}

Which ingredients can you combine with lactic acid?

Lactic acid plays nicely with everything else in your medicine cabinet, which is part of the reason why it’s fairly easy to incorporate into your skin care routine.

If you’re prone to oiliness or breakouts, for example, it can be helpful to look for a product that pairs lactic acid with salicylic acid, suggests Dr. Graf. While the former is water soluble, salicylic acid is oil soluble. This means that it can penetrate through and dissolve oil, which makes it able to go deeper into your pores to clear out whiteheads and blackheads. Meanwhile, the lactic acid offers more general exfoliation, she explains.⁸

Dr. Lolis says lactic acid also works well with those PHAs we mentioned earlier, such as gluconolactone or lactobionic acid. They’re also gentle (so you don’t have to worry about them being overkill when combined with lactic acid). And as a bonus, they have antioxidant properties.⁹

Both dermatologists note that there are no ingredients that will necessarily negatively interact with lactic acid. However, if your skin is super sensitive, Dr. Lolis says it’s not a bad idea to avoid using it at the exact same time as other potent actives, such as retinol (and other retinoids) and vitamin C. It’s best to apply lactic acid at night anyway (more on that below), which is helpful if you want to combine it with stronger actives. For example, you can alternate lactic acid with a retinoid, say, during your nightly routine. Vitamin C, on the other hand, is best used in the morning, so you can still use lactic acid come bedtime.

While it’s really unlikely to cause any side effects, if you have a condition that compromises your skin barrier, such as eczema or psoriasis, Dr. Lolis cautions to treat that first before adding lactic acid to your routine, as you don’t want to exacerbate your symptoms. To that point…

What’s the best way to use lactic acid in your skin care routine?

Even though this ingredient is super gentle—have we hammered home that point enough?—Dr. Lolis and Dr. Graf agree that it’s always smart to introduce any kind of chemical exfoliant via a product that washes off. It’s an easy way to help your skin initially acclimate before opting for a leave-on formulation, they say.

Their advice: Look for a cleanser with lactic acid, like Cetaphil’s Smoothing Relief Body Wash ($8, Amazon) or Dermalogica’s Skin Resurfacing Lactic Acid Cleanser ($48, Sephora). Massage it into your facial skin and leave it on for 30 seconds before rinsing so the ingredient has enough time to take effect, says Dr. Lolis. If you can tolerate that, you can move on to leave-on products; lactic acid serums, toners, and peel pads are all good options, according to Dr. Graf. For example, she likes Glytone’s Lactic Superficial Retexturizing Serum ($70, Dermstore) and Cosmedix’s Prep and Reset Dual-Sided Lactic Acid Exfoliating Facial Pads ($65, Dermstore). You may also find lactic acid in body moisturizers. AmLactin’s Daily Moisturizing Lotion ($14, Amazon) is one to try.

Regardless of the product you pick, Dr. Graf recommends reserving lactic acid for evening use. At bedtime, you want to use ingredients that are going to help the skin’s renewal process, which kicks in overnight.¹⁰ (Basically, your skin moves into repair and healing mode while you snooze.) Lactic acid falls on that list, given its abilities to exfoliate, hydrate, and bolster your skin barrier. As we said, it’s a hard little worker that’s nice to pretty much everyone’s face.

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