• Lactic acid is known for its strong exfoliation action. (Huey-Chun Huang, Lactic Acid Bacteria and Lactic Acid for Skin Health and Melanogenesis Inhibition, 2020)
• When compared to its other members of the AHA family, the unique thing about lactic acid is that it moisturizes the skin. (Spada F, Skin hydration is significantly increased by a cream formulated to mimic the skin’s own natural moisturizing systems, 2018)
• A little-known fact is that lactic acid is also an antioxidant.; it can squelch heavy metals that may be present in water, preventing them from attacking healthy cells and releasing collagen-degrading enzymes. (MDPI), (Yuki YAMAMOTO, 2006), (Barbara Algiert-Zielińska MSc, 2018)
• Lactic acid can prove to be particularly helpful in reducing hyperpigmentation and helping you even out your skin tone, primarily due to its exfoliation properties. (SURGEONS, AMERICAN SOCIETY OF PLASTIC)
• Lactic Acid Can Significantly Reduce Breakouts and Fine Lines. (Today Medical News)
• Lactic acid strengthens skin’s barrier by encouraging it to make more ceramides, a key component of healthy skin. (Fabrizio Spada 1, 2018) 
• Lactic acid and glycolic acid often are used to treat acne. (Sheau-Chung Tang1, Dual Effects of Alpha-Hydroxy Acids on the Skin, 2018)
• Lactic acid used to treat keratosis pilaris, a.k.a. “chicken bumps” that appear on the backs of your arms or on the legs. (MIGALA, 2020)
• Lactic acid as an effective antimicrobial. It works alongside them as a treatment for moderate skin conditions like psoriasis, eczema, and acne. (WebMD Editorial Contributors,Dan Brennan, MD, 2021)
• Overall, according to the Food & Drug Administration (FDA) some of the potential benefits of using lactic acid on the skin include: (US Food & Drug Administration, 2022)
• Sloughing away accumulated dead skin cells.
• Increasing cell turnover.
• Removing acne causing bacteria.
• Improving skin tone and texture.
• Smoothing fine lines and surface wrinkles.
• Unblocking and cleansing pores.

Lactic acid is the second most well-known and most well researched among the AHAs. Lactic acid is probably one of oldest actives, about which women have noticed that it has some nice benefits to the skin.

Legend has it that in ancient Egypt Cleopatra bathed in sour milk. And yes, you guessed it right: sour milk is a major natural source of lactic acid.

As an AHA it’s also true of lactic acid that it can gently lift away dead skin cells revealing the fresher, smoother, nicer skin underneath (Huey-Chun Huang, 2020). This is an awesome property of AHAs, and this alone makes us a total fan!

But just like glycolic acid, lactic acid also knows some more. However, the “some more” is a bit different for the two of them. The differences stem from the fact that the molecule of lactic acid is larger.

Because of the larger molecule it can penetrate the skin less effectively. This means on the one hand that lactic acid is more gentle and on the other hand that the anti-aging properties are probably a little less effective.

While the collagen boosting ability of lactic acid is not so well proven there are studies that show that it also has great anti-aging properties (if used in the right concentration at the right pH).

A study (Choi, 2001)done in 1996 compared a 5% and a 12% lactic acid treatment and examined their effect on the outer (epidermis) and middle (dermis) layer of the skin. The result was that both treatments had nice exfoliation effect, but the 5% treatment only affected the epidermis while the 12% treatment affected both the dermis and the epidermis.

Lactic acid is a natural alpha hydroxy acid that is derived from milk. It removes the upper layers of skin and allows new, lighter skin to be revealed. In addition to helping with hyperpigmentation around your thighs, elbows, and underarms, it can also help promote collagen production and exfoliate other areas of your body like the hands and feet. (WebMD Editorial Contributors, Dan Brennan, MD, 2021) 

1. Exfoliation: ( (Huey-Chun Huang, 2020) Just like other AHAs, lactic acid is known for its strong exfoliation action. It removes dead skin cells from the top layer of your skin, ensuring new cells get generated. Exfoliation is one of the most important aspects of skincare because if you let dead skin cells accumulate, it will lead to skin problems like a dull skin tone, acne, and even the appearance of fine lines. Lactic acid will get rid of the dead cells, ensuring your skin looks bright and is healthy from within.Lactic acid speeds up cell turnover and stimulates cell renewal—the process by which your skin sheds old cells and replaces them with new ones. (Sheau-Chung Tang 1, 2018) As a result, it gives you a brighter complexion, as well as smoother and softer skin.
2. Moisturisation: (Spada F, 2018)When compared to its other members of the AHA family, the unique thing about lactic acid is that it moisturizes the skin. Research published in the journal Clinical, Cosmetic, and Investigational Dermatology found that lactic acid can actually mimic the skin’s own mechanism of moisturization and improve its ability to keep itself hydrated, thus preventing dry skin. Ensuring that the skin stays well-moisturized also minimizes the risk of fine lines. It helps improve the skin's natural moisture factor or the way it keeps itself hydrated.
3. Collagen stimulation: (MDPI), (Yuki YAMAMOTO, 2006), (Barbara Algiert-Zielińska MSc, 2018) You see, we need collagen because it is a building block for the skin and ensures your skin stays youthful. After the age of 25, its production starts to decline. Turns out, you can apply lactic acid on your skin to stimulate collagen production! This will ensure that you stay clear of signs of aging. A little-known fact is that lactic acid is also an antioxidant; it can squelch heavy metals that may be present in water, preventing them from attacking healthy cells and releasing collagen-degrading enzymes.
4. Reduces Hyperpigmentation: (SURGEONS, AMERICAN SOCIETY OF PLASTIC) If you’ve noticed hyperpigmentation on your skin, you should definitely look into lactic acid. Lactic acid can prove to be particularly helpful in reducing hyperpigmentation and helping you even out your skin tone, primarily due to its exfoliation properties. There’s no doubt that lactic acid can be great for your dermatological health, but also keep in mind that it can cause sensitivity to the sun. Hence, apply it only during the night, and don’t leave your home without applying sunscreen the next morning. You can use lactic acid to boost your skin health with just a little care!

Lactic Acid Can Significantly Reduce Breakouts and Fine Lines. (Today Medical News) Lactic acid strengthens skin’s barrier by encouraging it to make more ceramides, a key component of healthy skin, it’s often recommended for sensitive skin, although all skin types can use it. (Fabrizio Spada 1, 2018)    

Lactic acid also strongly influences skin’s microbiome, helping to keep its first line of defense strong by positively interacting with a neuropeptide in skin’s surface known as Substance P, resulting in quick diffusion of signs skin is stressed. (MDPI) (R. Sfriso, 2019)Its discoloration-fading results also apply to post-breakout marks involving excess melanin (skin pigment) and it helps hasten the fading of pink-to-red post-breakout marks. (Shokeen, 2016)

Lactic Acid for Acne:

Lactic acid and glycolic acid often are used to treat acne. Products that contain lactic acid include cleansers, creams, and lotions. It is often used in at-home peels and masks. The research evidence suggests that the time of exposure to lactic acid, as with the masks and peels, will contribute to how effective it is. (Sheau-Chung Tang1, 2018)

Lactic acid as an effective antimicrobial. Some research suggests that lactic acid and probiotic supplements can help with sensitive skin. By teaming up to fix certain inflammatory reactions, they can both give a microbial balance to the skin. While probiotics promote more in-depth regulation by balancing the gut, lactic acid works alongside them as a treatment for moderate skin conditions like psoriasis, eczema, and acne. (WebMD Editorial Contributors,Dan Brennan, MD, 2021)

Beyond the face, lactic acid is often incorporated into body lotions. Most notably, it’s used to treat keratosis pilaris, a.k.a. “chicken bumps” that appear on the backs of your arms or on the legs. The skin condition is harmless but is often bothersome. Lactic acid can take care of these little bumps, says Dr. Hollmig, but you must apply the lotion regularly long-term for best results. (MIGALA, 2020)

Typical use level is between 1-20%.

Lactic acid up to a maximum level of 2.5% and a pH ≥ 5

The lactic acid exfoliant step in your skincare routine is done once or twice daily after cleansing and toning. After application, you can follow with your other leave-on products, finishing with sunscreen during the day and moisturizer (if needed) at night.

• Do I need lactic acid in my skincare?

Lactic acid has a few benefits for skin. This alpha hydroxy acid (AHA) removes dead skin cells, lightens dark spots, and improves the look of fine lines and wrinkles on all skin types—including sensitive skin. Lactic acid is used in over-the-counter (OTC) skin care products and professional treatments.

• Does lactic acid brighten skin?

Through its exfoliating action, lactic acid is used to swipe away dead skin cells, brighten complexion, lighten hyperpigmentation, and improve the appearance of fine lines. Different than other acids, it's also moisturizing, which is why you'll see it show up across skincare products.

• What skin type is lactic acid best for?

Lactic acid works on all skin types, however is 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.

• Is lactic acid better for oily or dry skin?

Glycolic Acid may be better tolerated by normal to oily skin types, and is often advised for uneven skin texture since it may penetrate deeper into the skin layer. Lactic Acid, on the other hand, is a milder exfoliant that can be ideal for dry or sensitive skin.

• Canlacticacidbe usedonthe body?

Lactic acid is a gentle yet effective exfoliating ingredient for rough, dry skin anywhere on the body, especially scaly skin on your legs, bumpy skin on the backs of your arms, elbows, knees and calluses.

• Does lactic acid tighten pores?

Alpha hydroxy acids like glycolic acid and lactic acid can have a retexturizing effect on the skin. Using products that contain these ingredients may help to reduce the appearance of enlarged pores by helping to sweep away dead skin cells, oil and other debris that has built up inside pores and on the skin's surface.

• Is lactic acid an AHA or BHA?

Lactic acid is another common AHA. Unlike other AHAs made from fruits, lactic acid is made from lactose in milk. It's also known for its significant exfoliation and anti-aging effects.

• How often should you apply lactic acid?

Start by following the instructions on the packaging—many advise using lactic acid every other night, or even once or twice a week. Slight tingling or redness is normal, but if you experience anything more intense, talk to your derma. Layer on a moisturizer.

• Do I moisturize after lactic acid?

Lactic acid is a time-tested exfoliator that provides deep hydration and helps smooth out fine lines and wrinkles. To incorporate lactic acid into your skincare routine, start with a cleanser, followed by serum, and then moisturizer.

• Is lactic acid safe to use in pregnancy?

AHA treatments are safe to use during pregnancy. However, a person should speak with a dermatologist before undergoing treatments if they are pregnant

• Is lactic acid safe to use alongside other anti-aging products?

People can alternate using products containing lactic acid with other anti-aging products, such as vitamin C and Retinoid creams.

• How long does lactic acid take to work?

The length of time it takes lactic acid to work depends on the product and the intensity of the chemical peel.

• Who should use lactic acid?

Anyone with acne prone skin. Just remember to do a patch test first, to detect any side effects or further irritability to the skin.

• What is lactic acid best known for?

Lactic acid is best known for its exfoliating properties; however, it boasts other benefits as well.

• Does lactic acid help clear skin?

Lactic acid is a type of AHA present in many exfoliating skin care products. It removes the top layer of the dead skin cells and can help improve skin texture, reduce dark spots, smooth fine lines, and cleanse pores.

• Do you leave lactic acid on overnight?

Many skincare experts recommend going slow when you first start using lactic acid, but ours is gentle enough for regular use. But because of its restorative properties, it's best to use lactic acid at night. See our previous blog for serious overnight skincare.

• Is lactic acid better than hyaluronic acid?

While lactic acid will remove those dead skin cells, hyaluronic acid nourishes the skin. There are many overlaps in the uses of these two 'acids,' but the two key differences are: Lactic acid can be used to treat acne, whereas hyaluronic acid cannot;

• Do you apply lactic acid on wet skin?

No, you apply to dry skin directly after cleansing and follow with your other products.

• Is lactic acid as good as retinol?

Lactic Acid can be a great alternative to retinol for clients who cannot use retinol or cannot tolerate a retinol nightly, for its smoothing, brightening benefits. If your skin can tolerate it, you will experience the best results if both products are incorporated in your routine.

• Does lactic acid make skin sensitive to the sun?

Like other AHAs, lactic acid increases sun sensitivity, so you should never use them in the morning.

• Does lactic acid make skin glowy?

It brightens Skin. Exfoliation can revive your skin, taking it from dull and tried to glowing and healthy. With lactic acid sweeping away your dead skin cells, you'll find your complexion looks visibly brighter and your skin tone appears even.

• Does lactic acid get rid of dark circles?

The most frequently used peels for dark circles are arginine and lactic acid peels.

• Do dermatologists recommend lactic acid?

"Lactic acid is the preferred acid for sensitive skin," Dr. Jaliman says. Still, like other AHAs, you should be cautious when trying lactic acid for the first time. Experts suggest not using products that contain lactic acid when using retinol, since the combination could cause redness.

• How many lactic acid peels to see results? 

Your best bet in this case would be using a Lactic Acid peel, 1-2 times per week. Lactic acid is less irritating and drying then Glycolic Acid, and helps skin retain moisture better.

• How much percentage of lactic acid is good for skin?

When using lactic acid in 12% concentrations, the skin gets firmer and thicker. As a result, there is an overall smoother appearance and fewer fine lines and deep wrinkles.