How Lactic Acid Benefits Your Skin: A Complete Guide

by Christine Tusher October 20, 2022

Squalane + Lactic Acid Resurfacing Night Serum

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 Resurfacing Night Serum featuring ingredient imagery

What Is Lactic Acid

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.

How Lactic Acid Benefits The Skin

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.

4 Key Benefits Of Lactic Acid For Skin

  • Reduces the look of aging. When concentrated to at least 5%, lactic acid can penetrate both the dermis and epidermis firm skin, improving the appearance of fine lines and wrinkles
  • May reduce acne. Lactic acid may also benefit oily and acne-prone skin by helping to reduce excess sebum, control acne-causing bacteria, unclog pores, reduce inflammation and helping acne medications penetrate better.
  • Helps Skin Hold Moisture. Because lactic acid helps moisture bind to skin, the new skin it helps to uncover appears smoother and better hydrated.
  • Improves The Look Of Dark Spots. Acne and sun exposure can cause areas of damaged, darkened skin. As lactic acid increases cell turnover, it helps newer, healthier skin cells replace the damaged ones more quickly to reveal brighter, more even-looking skin.
  • Lactic Acid vs. Glycolic Acid

    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.

    2 Bottle of Lactic Acid Resurfacing Night Serum with goop

    About Our Squalane + Lactic Acid Resurfacing Night Serum

    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!”

    How To Use Our Lactic Acid 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.

    Shop Squalane + Lactic Acid Resurfacing Night Serum

    Christine Tusher

    Christine Tusher
    Christine Tusher


    As a lifestyle writer and journalist, I’m excited to bring my passion for storytelling to Biossance as an Engagement Content Writer. Two things you should know about me: I have a deep love of the ocean (especially sharks) and I’m obsessed with clean beauty. My bathroom cabinet is literally overflowing with my many-layered sustainable skincare routine. This combo is what led me to buy my first bottle of Vitamin C Rose Oil. I was so impressed by the way it improved my skin that I wanted to shout this brand from the rooftops. Three years later, and here I am doing just that. I’m excited to be on this journey of clean beauty innovation with Biossance, and to share it with you here on the blog.

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