From Cleopatra to Marilyn Monroe, beauties through the ages have reputedly sworn by milk baths as the secret to smoother, softer skin. And it’s not just an old wives’ tale: sour milk is rich in lactic acid, a gentle alpha hydroxy acid that exfoliates while improving skin tone and texture.
Fortunately, you don’t have to douse yourself in day-old milk to reap the benefits of lactic acid for your skin. Today’s lactic acid serums - like our Squalane + Lactic Acid Resurfacing Overnight Serum - offer targeted, cruelty-free treatment to improve the look of fine lines, uneven texture, and even help with blemishes too.
Read on to learn how to use lactic acid to get more even, radiant skin.
Lactic acid is an alpha hydroxy acid that is naturally found in the skin as sodium lactate. While we usually think of AHA’s as powerful exfoliants (which they are), lactic acid is special in that its unique structure allows it to bind water within skin, making it an integral part of the skin’s natural moisturizing factor.
Not only does lactic acid work within the skin to keep it hydrated, it also strengthens the moisture barrier by encouraging it to make more ceramides while positively interacting with neuropeptides to support the skin’s microbiome.
When applied topically to the skin, lactic acid breaks down the proteins that bind skin cells together, increasing cell turnover while providing added hydration. This helps to improve the skin’s appearance in several important ways.
Of course, lactic acid isn’t the only buzzy AHA on the block. Glycolic acid, is also a powerfully beneficial exfoliant. When choosing an AHA product that’s right for your skin, it’s important to understand the differences between lactic acid vs. glycolic acid.
Lactic acid molecules are larger than glycolic acid molecules, meaning it doesn’t penetrate as deeply into the skin. That makes lactic acid a better choice for people with sensitive skin, as its less likely to cause irritation or disrupt the skin’s moisture barrier. It also means less systemic absorption, making it safe to use during pregnancy or if you’re breastfeeding.
Lastly, there’s lactic acid’s unique ability to bind moisture to skin. While glycolic acid can be moisturizing under certain circumstances, moisture binding is a magic trick it doesn’t perform automatically.
Our science-backed lactic acid serum formula uses 10% vegan lactic acid to penetrate the dermis and deliver all of lactic acid’s benefits to the skin as deeply as possible without causing it to peel. But we didn’t stop there: we combined it with sugarcane-derived squalane for added hydration and clover extract to boost lactic acid’s exfoliating power by further encouraging cell turnover.
In clinical trials, 100% of participants reported that our Squalane + Lactic Acid Resurfacing Night Serum improved the appearance of enlarged pores, fine lines, and wrinkles.
“I’m an esthetician, my skin tends to be more acne-prone and oily. I’ve tried multiple products and serums and this one was a game changer!” says Biossance customer, Malia. “It not only cleared my acne but it left my skin smoother and brighter. My skin has never been better and I get compliments all the time! My sister uses the same exact serum for anti-aging. We both recommend this product to everyone who’s looking for a great serum!”
As the name suggests, our Squalane + Lactic Acid Resurfacing Night Serum is meant to be used after your evening cleanse and before moisturizing. Our 10% lactic acid serum loosens dead skin cells on the top layer of your skin, causing no visible peeling. Instead, the old skin cells rinse off when you cleanse your face the morning after use, exposing a fresh layer of brighter, smoother-looking, better-hydrated skin underneath.
This is why it’s crucial to use a gentle, SPF 30 sunscreen such as our Squalane + Zinc Sheer Mineral Sunscreen the morning after using our lactic acid serum. Failing to protect that fresh layer of cells can cause sun damage, resulting in premature aging and hyperpigmentation.
If you’d like to use multiple active ingredients, use them at different times or on alternate days to help prevent irritation. For example, you can use our Squalane + Vitamin C Dark Spot Serum during the day, and our Squalane + Lactic Acid Resurfacing Night Serum at night.
If you’re using a retinol product, alternate evenings between our lactic acid serum and retinol for maximum efficacy with minimal irritation, and make doubly sure to wear SPF.