5 Things to Know About Lactic Acid in Skin Care

Read on to learn some surprising details about lactic acid and skin care.
©iStockphoto/Serghei Starus

Look around your kitchen and you'll find a handful of natural health remedies, from cough-soothing honey to puffy eye-reducing cucumbers. In fact, your refrigerator may hold a real-life fountain of youth: milk. It contains lactic acid, which is the key to healthy, smooth skin.

Lactic acid is an alpha hydroxy acid (AHA). AHAs are acids derived from foods, and, as it turns out a type of acid that's safe to apply to our skin. Citric acid, for example, from citrus fruits (lemons, oranges, etc.) is an alpha hydroxy acid. Lactic acid is found in sour milk, but you may have also heard of or tried other AHAs, such glycolic acid, from sugar cane, which is also a popular ingredient in anti-aging topical skin care products.


AHAs applied topically and regularly to your skin help reduce the appearance of aging, and they can be an especially good remedy against fine lines, wrinkles and other signs of premature aging from sun damage. Let's talk about five important benefits -- and the drawbacks -- of adding lactic acid to your skin-care routine, beginning with improved skin texture.

5: Lactic Acid and Skin Texture

Products such as cleansers, lotions and peels that contain lactic acid are applied topically to the skin, and they get right to work. These products improve skin's texture through exfoliation -- AHAs encourage the skin to slough off its old, dead skin cells revealing the glow of healthy skin cells hidden underneath. They help reduce the appearance of acne scars, age-related spots and pigmentation. They also help firm up sagging skin, fine lines and wrinkles by promoting collagen growth in the deeper layers of your skin.

Not all skin texture problems can be solved with an AHA product. If your skin develops thick patches or there are areas of swelling and lactic acid doesn't seem to be working, it's time to see a doctor. Some skin conditions are caused by rosacea, skin cancer and other underlying illnesses such as diabetes, a vitamin deficiency or a thyroid problem.


4: Lactic Acid Creams and Lotions

If you looking for a product that will treat the damage done to your skin through years of sun exposure try creams and lotions (creams are usually thicker than lotions) containing lactic acid. Regular use of AHA topical creams or lotions is known to reduce the appearance of fine lines and wrinkles because it stimulates collagen production in your skin.

They're also known to improve hyperpigmentation, dark patches or spots that develop on the skin. When you use products that contain concentrations of more than 5 percent lactic acid in their ingredient list, you may find it lightens your skin, which is exactly what you want if you have age spots or other discoloration.


Applying AHAs in cream or lotion form is also helpful in treating dry skin. A cream that contains, for instance, lactic acid and an emollient or humectant is a two-step knockout: the lactic acid first thoroughly exfoliates the skin, allowing more moisture through to the new skin below.

3: Lactic Acid Peels

Depending on your skin care goals, you might want to up the ante from lactic acid lotions to a lactic acid peel, also known as a chemical peel or a facial peel. Peels allow for the greatest concentration of lactic acid -- consider this bringing out the big guns against premature aging and sun damage.

Concentrations of acids vary depending on the level of damage being treated, allowing for superficial to deep peel options. Alpha hydroxy acid peels, including lactic acid, are offered in concentrations ranging from 10-70 percent, with 50-70 percent being the most common concentrations used in facial peels [source: Fabbrocini].


At concentrations greater than 30 percent, a lactic acid peel is a chemical exfoliant, dissolving dead skin cells from the top layers of skin.

AHA peels are used with good outcomes for people with pigmentation conditions such as melasma, lentigo or freckles, and may help reduce or improve the appearance of acne scars.

Peels are usually considered part of a skin care routine, not just a one-time thing. While they may help you recapture your youthful glow, take note your face may be noticeably red for several weeks post-peel.

2: Take-home Kits or Visit the Doctor's Office?

If you're one of those people who feels brave enough to try a chemical peel at home you'll find there's a kit for that.

You don't need a visit to your doctor's office to try out lactic acid skin care products. Put down the carton of milk, as there is no milk bath in your future, Cleopatra. But you will find a variety of products in the skin care and beauty aisles of your local store.


There is quite a variety when it comes to do-it-yourself chemical peels and the most important thing to pay attention to while you decide which kit is for you is the peel's strength. Strength varies from kit to kit, and you'll find a range of products containing up to 70 percent lactic acid. This is an instance where stronger is not always better. In fact, it's probably better to leave anything with lactic acid concentrations greater than 10 percent in a doctor's hands [source: WebMD]. Too much lactic acid is never a good thing and may cause irritation and other skin complaints.

Always read the instructions from cover to cover before you begin, and follow them precisely.

1: Drawbacks to Lactic Acid in Your Skin-care Regimen

Alpha hydroxy acids may be a good remedy against fine lines and wrinkles, acne and acne scarring, and other skin problems but they don't come without problems themselves.

AHAs are known to have a few drawbacks -- some people may not find this bothersome while others find they can't live with the side effects. It's going to depend on your own individual factors but two big things are the standouts: your skin type and the strength of the product you're using.


The most common side effect of skin care products containing lactic acid is skin irritation. It may sound a bit backward that the very thing you're applying to your skin to make it smooth, young and beautiful causes peeling and redness, but that's why there's a saying about suffering for your beauty, right? Irritation is often temporary, and while it may be worse for those with sensitive skin even the oiliest, inflamed skin may experience some peeling or irritation.

Using lactic acid creams, lotions and peels also increases your skin's sensitivity to the sun, so it's important to be vigilant about sun protection, from regular applications of sunscreen to remembering to wear a hat, every day.

For more information, see the links on the next page.

Lactic Acid Skin Care FAQ

Which acid is best for acne?
Salicylic acid is the best option for acne-prone skin. A type of beta-hydroxy acid, it's well-known for its ability to exfoliate the skin and keep pores clear. It's commonly in serums and cleansers with concentrations between 0.5 and 2 percent, though it's found in higher amounts in peeling agents used at dermatology clinics.
Is lactic acid good for your skin?
Lactic acid helps improve skin's texture through exfoliation and keeps it moisturized. When you use lactic acid regularly, it helps with anti-aging, firming up sagging skin, fine lines and wrinkles by promoting collagen growth. It also treats hyperpigmentation, dark patches, or spots on the skin that are common with aging.
Which is better glycolic acid or lactic acid?
Lactic acid and glycolic acid are the two best researched alpha hydroxy acids (AHA) and both have notable benefits. However, lactic acid is generally gentler and more hydrating while glycolic is better for sun-damaged skin. Never put multiple acids on at the same time though, as it may irritate the skin.
Can you leave lactic acid on overnight?
Lactic acid serums are best used at night because they can cause sun sensitivity. They can be left on overnight with any other nighttime skin products you usually use. Other products, like at-home peels, should be used and left on according to their specific instructions.
How often should I use lactic acid on my face?
It depends on the strength of the product you're using. Too much lactic acid is never a good thing. If you're simply using a cleanser or moisturizer with a low concentration, you can use it daily. However, if the concentration is higher, dilute the product or reduce use to three to four times per week until your skin has adjusted. Anything with lactic acid concentrations greater than 10 percent should be left in the hands or a doctor of dermatologist.
Is lactic acid safe to use?
Generally, yes it's completely safe. The only drawbacks to using this AHA are mild temporary irritation and a slight increased sensitivity to sun exposure.

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More Great Links

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