The Science of Lactic Acid in Skin Care
Have you ever wondered why lactic acid has been a popular skin care ingredient for thousands of years?
Derived from natural sources like milk, fermented fruit or yogurt, this hydroxy acid has many benefits for dry, resistant skin.
In this comprehensive guide, we explain what lactic acid is, where it comes from, its benefits, possible side effects and its uses in skin care.
But before we get into the details, let’s start with the basics.
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What is Lactic Acid?
Lactic acid in skin care is a hydroxy acid that can play a positive role in many everyday situations. (3) Lactic acid is an alpha hydroxy acid (AHA) that comes from natural sources like milk.
This class of AHAs and glycolic acid are known for their exfoliating and moisturizing properties, making them one of the most common ingredients in skin care products. (2)
Where does lactic acid come from?
Lactic acid used in skin care products does not come from the human body, although we do produce it ourselves.
For skin care products, lactic acid can be obtained from a variety of sources, but one of the most common sources is milk.
During the extraction process, lactose is fermented with the help of bacteria, which creates a chemical reaction that produces lactic acid.
(6) This natural manufacturing process ensures the safety and effectiveness of lactic acid used in skin care products.
The lactic acid produced during these reactions is used in a variety of products such as moisturizers, cleansers, sunscreens, lip balms, etc. along with other ingredients to perform their respective functions.
Common sources of lactic acid in skin care are:
Fermented fruits
Milk
Mushrooms
Sugar cane
Yogurt
Benefits of Lactic Acid in Skin Care
Lactic acid is a versatile and multi-purpose ingredient in skin care products. The main benefits of this compound in skin care include:
Humectant – Like other humectants such as glycerin, hyaluronic acid, and panthenol, lactic acid locks in moisture, ensuring that the skin feels hydrated.
Lactic acid does not dry out the skin. (7,8) It is one of the so-called “natural moisturizing factors” (NMFs).
Exfoliation – Hydroxy acids like lactic acid have a low pH, which means they are acidic and can help remove dead skin cells.
(9) The skin is constantly exfoliating naturally, and this ingredient can support this process. (1) Exfoliation has anti-aging effects, treats pigmentation spots (13), and boosts collagen synthesis.
Acne Care – Another benefit of a low pH is its antibacterial properties. (10) Ingredients like lactic acid can eliminate acne-causing bacteria on the skin.
Lactic acid’s exfoliating properties also help to clear dead skin from pores. This ingredient is found in many cleansers because it effectively removes dirt and impurities from the skin. (11)
All of these benefits make lactic acid a great choice for acne-prone, dry, or aging skin that can tolerate a low pH.
Research has also shown that lactic acid is a good treatment for psoriasis (5) and xerosis.
To find out if lactic acid is right for your skincare routine, take our quiz by clicking the button below!
What skin conditions can lactic acid treat?
Lactic acid is used to treat a variety of skin conditions. The most common side effects are:
Acne
Skin irregularities
Pale skin
Pigmentation
Melasma
Keratosis pilaris
Rough skin
Sunspots
Xerosis
Folding
Side effects of lactic acid in skin care
Lactic acid has been extensively tested for use in skin care and is very safe to use.
(3) CIR, EWG and other research organizations have published reports on the safety of lactic acid in skin care products.
EWG emphasizes that the specific application of lactic acid determines its safety and rates it on a “1-5” scale.
At concentrations of 10% or less, there is a potential for irritation to sensitive skin. (12)
Lactic acid remains one of the least irritating hydroxy acids to the skin, but that doesn’t mean it’s right for everyone.
There are really only two main aspects to consider when choosing a lactic acid product:
It has a smell – this may not bother everyone and can be covered up or washed off, but lactic acid products generally have a noticeable smell.
Even extremely sensitive skin can experience irritation or burning – some people simply can’t tolerate products or ingredients with a low pH.
Lactic acid is an alpha hydroxy acid (AHA), so it can slightly thin the stratum corneum and slightly reduce the skin’s natural SPF.
Therefore, if you use an AHA in your skincare routine, be sure to use SPF during the day.
Lactic Acid in Skin Care
For centuries, some of history’s greatest beauty icons have used lactic acid.
Cleopatra, known for her legendary aesthetic, is said to have bathed in yogurt that contained large amounts of lactic acid. (4) This practice left her skin incredibly soft and glowing.
Similarly, Scarlett O’Hara in Gone with the Wind rubbed buttermilk onto her shoulders to treat dark spots of hyperpigmentation. (5)
If you’re looking for an ingredient with countless historical precedents to use in your daily routine, lactic acid may be the right choice for you.
Lactic Acid Fights Acne
The antibacterial properties of lactic acid make it an effective tool in the fight against acne. It can help reduce acne by killing acne-causing bacteria and exfoliating the skin’s surface.
However, people with sensitive skin should be careful, as lactic acid can cause a slight burning sensation. (14)
Lactic acid fights skin aging
Exfoliation is key to anti-aging, and lactic acid is a great option. It helps reduce fine lines and wrinkles by removing dead skin cells and boosting collagen production.
(1,9) In addition, lactic acid can counteract photodamage, thereby slowing the aging process. (15)
Lactic acid for dry skin
Lactic acid’s moisturizing properties make it a great choice for dry skin. It locks in and holds moisture, keeping your skin nicely hydrated.
(7) Lactic acid is relatively gentler on the skin than glycolic acid, but still delivers effective results.
It’s a great alternative to other moisturizing ingredients like glycerin and hyaluronic acid.
Lactic acid is especially found in leg products, such as the prescription product AmLactin.
Conclusion
It’s crucial to incorporate lactic acid into your skincare routine.
Whether you suffer from acne, are looking for anti-aging benefits, or are battling dry skin, versatile lactic acid is the right choice.
If you’re not sure where to start, fill out the Baumann Skin Type Questionnaire to find the best product for your individual skin needs.
With the power of lactic acid, your skin will become healthier and more radiant!