Rumor has it that Cleopatra — known for her beauty and charm — took daily milk baths that contributed to her glowing, smooth skin. The science behind it actually makes sense: Dairy (as well as fruits, vegetables, and some plants) naturally produces lactic acid, an exfoliant that is gentle enough for even the most sensitive skin types. Today, the idea of pouring gallons of milk into your tub is probably a bit extravagant for most, but luckily there are more efficient, effective ways to infuse lactic acid into your skin care routine: The hero ingredient is found in many over-the-counter products to achieve similar silky-soft skin results.
If beauty hacks used by the Egyptian royal is not enough to convince you that you should be using a lactic acid immediately, we had the pros provide a beginner’s guide. Here, we will answer all of your questions, from what is lactic acid for the skin, the best lactic acid for skin types and goals, and of course, how to apply lactic acid to the skin safely.
Consider this to everything you need to know so you can decide whether or not it is right for you (with the green light from your dermatologist, of course).
Meet the Experts
Y. Claire Chang, M.D., is a board-certified cosmetic dermatologist at Union Square Laser Dermatology in New York.
Melissa Kanchanapoomi Levin, M.D., is a New York-based dermatologist and founder of Entiere Dermatology.
What is lactic acid?
So, what is lactic acid? And specifically: what is lactic acid for skin texture and goals? “Lactic acid is an alpha hydroxy acid (an AHA) that’s a natural chemical exfoliator, which helps remove the top layers of dead skin cells and increases cell turnover,” says Y. Claire Chang, M.D., a board-certified cosmetic dermatologist at Union Square Laser Dermatology in New York.
Lactic acid can be produced synthetically (in products), through a biologic process (like when you exercise), and can be found naturally in certain foods like milk and yogurt. Lactic acid for skin health is usually part of moisturizers, serums, or other products that are applied topically to the outermost layer of our face or body. “It has a similar structure as glycolic acid, but it’s known to be more gentle on your skin because it has a larger molecule size that makes it less potent and more tolerable,” she adds.
What are the main uses of lactic acid and what do the different strengths mean?
Like all ingredients that are promoted to fight aging, improve appearance and give us that lusted-after glow, lactic acid for skin health comes in a variety of options and potencies. “Lactic acid not only stimulates the exfoliation of skin cells but also increases ceramides, an important fatty acid in your skin to serve as a protective skin barrier,” says Melissa Kanchanapoomi Levin, M.D., New York-based dermatologist and founder of Entiere Dermatology. “At higher concentrations, lactic acid for skin is not only a gentle exfoliating option but at lower concentrations, it also increases the skin’s moisture level. It’s an amazing humectant, which means it has the ability to pull water into the outer layer of the skin,” she adds.
Who might benefit the best from lactic acid?
Most people will see a benefit of lactic acid for skin health goals — but some may opt for it more than others. “Lactic acid can be great for any skin type, and because lactic acid tends to be more gentle than other chemical peels, it’s an optimal option for those with sensitive skin — still using caution, of course,” says Chang.
A true multitasking ingredient, the benefits of lactic acid also include helping people who are looking to treat hyperpigmentation and pigment conditions (like melasma), sun spots, enlarged pores, uneven complexion and texture, and signs of aging. “It can also treat skin conditions like keratosis pilaris — more commonly known as ‘chicken skin,’” adds Chang.
Should anyone avoid it?
It is more about making sure you are layering your products properly. “If your existing routine already incorporates other AHAs, beta hydroxy acids (BHAs) or retinoids, you may encounter too much irritation, dryness, flaking, or redness,” says Levin.
What is the best lactic acid for skin? And what products can you pair it with?
Generally speaking, the best lactic acid for the skin is one that’s infused within products you already own or will use throughout the week. Think: a moisturizer or a serum. While you should always use sunscreen, now more than ever should you remember your daily dose of SPF. “The healing skin is particularly sensitive to the sun when using lactic acid in your routine,” says Chang. The exfoliating effect of AHAs can make your skin more sensitive to the sun’s ultraviolet radiation, so slather on a broad-spectrum formula with at least an SPF of 30. “You can combine it with moisturizing ingredients like ceramides and hyaluronic acid to increase your skin’s overall hydration.”
How often should you use lactic acid?
As with most products, this depends on the concentration of lactic acid that you use. For the best lactic acid for skin results, first, consider the texture and sensitivity of your skin. “In general, weaker strength lactic acids can be used daily, while higher strength lactic acids should be limited to two or three times per week as tolerated. If your skin is getting too irritated, red, and dry, it is important to take a break for a few days to allow your skin to recover,” says Chang.
How do you apply lactic acid to the skin?
You understand the benefits of lactic acid for skin health and you’re ready to give it a try. But now, you’re wondering, “How do you apply lactic acid to the skin?” After washing your face thoroughly, pat dry with a towel. Then, choose your lactic acid product. If it’s a serum, you will want to apply lactic acid to the skin via your serum. Or, apply lactic acid to the skin with your moisturizer. In other words: Go through your typical skincare routine, incorporating lactic acid into your steps a few times a week.
When will I start seeing results?
When using lactic acid for skin health, the amount of time it takes to see results will depend on the strength of the formula that you start with. You will probably notice a difference in brightness right away thanks to its exfoliating properties. But for best lactic acid for skin results over time, “start with a lower percentage of 5 to 10% and then assess how your skin looks after regular use over one month. If the results are effective, I recommend sticking to the same percentage, but if you’re not experiencing enough of a difference — and your skin’s tolerating it well — you can slowly increase the strength,” says Levin.
What is the most common mistake when using lactic acid for sensitive skin?
You’re not just interested in the benefits of lactic acid for the skin — you need to know how it reacts on delicate complexions like yours. Remember, Dr. Chang says if you have sensitive skin, the patch test is essential. “Especially if you have sensitive skin, it’s important not to skip patch testing,” says Chang. “Apply a thin layer of product to your forearm or neck to see whether or not you get a reaction.” It is important to do it for a few days in the same area, as sometimes allergic reactions can be delayed.
What does it feel like when you use it?
You know how to apply lactic acid to the skin — but if you have sensitive pores, you may be hesitant to get started. Especially if you’re someone who breaks out easily, do the patch test mentioned above to ensure you don’t have a reaction. Then, you can gradually build up to meet your lactic acid for health goals.
And remember, in most cases, it won’t be a jarring experience to introduce this superstar ingredient into your routine. What does it feel like? It depends on the strength and amount of lactic acid in the product. “You might feel a mild tingling or slight burning sensation while others may not feel anything at all. It’s normal to get some mild, temporary redness or irritation during and after using a lactic acid treatment,” says Chang. Stop using it if you feel excessive irritation and “if you’re experiencing extreme itchiness, swelling, or pain, it could be contact dermatitis,” she adds. If that occurs, head over to your dermatologist to get it checked out.
What is the most surprising thing people find when they start using it?
“Many patients are surprised at how well-tolerated lactic acids are. Over-the-counter formulations are typically very gentle. You’ll find that with daily use, there will be a gradual, noticeable improvement in overall complexion and tone of your skin,” says Chang.
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