10 Acids Used In Skin Care & What They Do

From exfoliation to hydration, there’s an acid for every skin care concern.

My desert island skin care ingredient would be acids. Buckets of them. Sure, it should probably be sunscreen, but hush. I love acids because there’s one to address every skin concern out there--and they’re so effective. But if you’ve spent too long staring at ingredient labels thinking “so many acids, so little time,” fret not.

Here are the 10 acids you need to know.

Acetic Acid

Commonly known as vinegar, acetic acid is generally too acidic to use straight up. Still, it has plenty of awesome beauty applications. Use it in a rinse to help your hair with hard water, dilute it for use as a toner, or even drink it to clear up your skin from within.

Azelaic Acid

This acid is typically available by prescription only, but it’s wildly effective for inflammation sufferers. It can fight rosacea and inflammation caused by acne, as well as help clear pores. If that's not enough, it does a number on dark spots, too.

Citric Acid

This acid comes from citrus fruits and is most commonly used as a pH adjuster in skin care products. It is technically an AHA, but don’t go rubbing lemons on your face to get its exfoliation benefits. Instead, choose a product like the Dr. Dennis Gross Alpha Beta Peel Pads that ensures its pH and concentration is appropriate for the skin.

Glycolic Acid

Glycolic acid is maybe the most common Alpha Hydroxy Acid around. It’s good for treating flaky or dull skin and hyperpigmentation, and it has the smallest molecules of any AHA, so it can penetrate deeply. You’ll see it in products from the drugstore aisles to high-end counters. It’s a great acid to start with if aging is a concern.

Hyaluronic Acid

Not all acids exfoliate! The popular acid kid, hyaluronic acid is a hydration master. It attracts water molecules to the skin to provide light moisture, making it an excellent choice for oily and acneic skin.

Lactic Acid

Another fantastic AHA for anti-aging, lactic acid is a better pick than glycolic acid if you have sensitive skin. It’s becoming available in more and more products, which is great news if you want smooth, soft, even skin without causing redness or irritation.

Oleic/Linoleic Acid

These are two different acids, but you’ll find them together in every kind of skin-friendly oil. The balance of concentration varies from oil to oil, and for that, you can check out Dani’s awesome chart, but here’s a cheat sheet.

  • Oleic = thick, rich, healing, anti-aging.
  • Linoleic = more astringent, anti-inflammatory, anti-acne.
  • Both = awesome for the skin.

Mandelic Acid

This is my favorite acid (and perhaps skin care ingredient) of all time. Mandelic acid is great for exfoliation beginners because it is gentler than glycolic or lactic acids. Unlike other AHAs, mandelic acid is oil soluble, allowing it to work within the pore as well as on the surface of the skin. If you have acne and hyperpigmentation you want to address, Mandelic acid can help with both.

Retinoic Acid

The acid to beat all acids when it comes to anti-aging. Available by prescription as the ingredient Tretinoin, retinoic acid actually thickens the dermis to fill in fine lines and wrinkles, while exfoliating the epidermis to fight dullness and acne.

Salicylic Acid

Salicylic acid is THE beta hydroxy acid of note. Unlike almost all AHAs, it can work inside the pores to loosen clogs and kill acne bacteria. Used at concentrations of 1 to 2%, it is less effective at exfoliating the skin’s surface, but a great choice for acne-prone skin.

  • Do you incorporate acids into your skin care routine?
  • Which acid would you take with you on a desert island?