By Emma Stessman
Putting acid on your skin seems exactly like the kind of thing your middle school science teacher would warn against. But more influencers and experts than ever are now touting acid-based products as the secret to smooth and glowing skin.
The most important thing to note before experimenting with the somewhat scary-sounding addition to your skin-care routine? Not all acids are created equal. Each has a unique set of properties that can help address different, common skin-care woes—from acne to wrinkles.
So, we asked Jenna Walsh, a skin therapist at Heyday, to explain the differences. For starters, there are two main types: alpha-hydroxy acids (AHAs) and beta-hydroxy acids (BHAs), she explains. AHAs are water-soluble and treat more surface-level issues, while BHAs are oil-soluble and seep into the skin to address deeper-set skin concerns. However, Walsh offers a word of caution on both. “Anytime AHAs or BHAs are included in your skincare routine, be extra careful around the sun,” she says. “They are known to increase photosensitivity, so be diligent about applying and reapplying sunscreen appropriately, even on cloudy days.”
If you’re in New York or Los Angeles, you can book a 30-, 50-, or 75-minute facial at Heyday (otherwise known as “the DryBar of facials”) and ask a licensed estheticians for personalized recommendations on the best acids and products for your skin. In the meantime, we had Walsh break down everything you need to know to start making acids a regular part of your routine.
Which Acid Is Best for Your Skin?
Best for smoothing complexion and fighting aging: Glycolic or lactic acid
Glycolic and lactic acid are two of the most commonly found AHAs. They work on the skin’s top layer, dissolving the bonds that hold dead skin cells together so that new skin cells can take their place, Walsh says. “AHAs are known for their ability to deliver noticable results in the visible appearance of skin, treating hyperpigmentation, rough texture, and fine lines,” she adds.
How to use it: If you’re looking to rid yourself of uneven texture or the beginnings of wrinkles, Walsh recommends selecting an exfoliant or serum containing glycolic or lactic acid. The Ordinary, for example, combines the two in its Peeling Solution, a powerful exfoliant made for twice-weekly use.
Best for treating acne: Salicylic acid
Even if you’re completely new to the skin-care game, you’ve probably used salicylic acid before (shoutout to everyone who used the Neutrogena pink grapefruit scrub in high school). The acid, found in teen acne products and high-end serums alike, is a BHA. Meaning, it can penetrate deeper into the skin to treat conditions like clogged pores and acne, Walsh explains. When applied topically, the acid not only exfoliates your skin by dissolving dead cells, but it also breaks down acne-causing oil.
How to use it: Depending on the seriousness of your acne, you may benefit from using occasional treatments like a mask (this one from Eminence can be used as a mask or spot treatment) or in more severe instances, a professional strength peel. Before adding this acid into your routine, you should consult an esthetician or dermatologist. “Overuse of salicylic acid can lead to stripping or over-drying of the skin, which can actually make breakouts worse,” Walsh says.
Best for soothing dry skin: Hyaluronic acid
Hyaluronic acid doesn’t fit into the main acid categories, nor does it actually dissolve anything, Walsh says. “It’s found naturally in our body to cushion and lubricate connective tissue, joints, eyes, and skin with a consistency similar to Jell-O,” she says. “It gives our skin that youthful bounce and healthy dew.” Natural supplies of the acid diminish with age, but when applied topically, you can help boost its levels to make up for lost suppleness and hydration.
How to use it: “Apply a thin layer in the morning and evening before moisturizing to provide dull, dehydrated skin with much needed moisture and fine line plumping,” Walsh suggests. Try a twice-a-day product, like Peach & Lily’s Korean-inspired refining serum.
Best for even skin tone: Ascorbic acid
Better known as simply vitamin C, ascorbic acid is a powerful antioxidant that can brighten and firm the skin, as well as boost collagen, strengthen skin elasticity, and provide free-radical repair from pollution damage, Walsh says.
How to use it: It’s best applied as a serum, and unlike the other acids, you likely won’t see its effects within the first week or two of use. “Its’ lightning abilities will take time to notice but are well worth the wait,” Walsh says. “Stay consistent and give your skin at least three to four months to complete several rounds of cell turnover before seeing a noticeable change.” For a more even skin tone, regularly apply an ascorbic acid serum, like this lightweight formula from Mario Badescu.