BHAs: Why Beta-Hydroxy Acids Are Key For Targeting Deep-Seated Skin Problems

When learning the ABCs of skincare, BHAs are one ingredient you should add to your study list. BHA stands for "beta-hydroxy acids," and it falls into the family of skin-friendly acids along with AHAs (alpha-hydroxy acids) and PHAs (polyhydroxy acids). Even if acid sounds a little harsh, these actives offer powerful benefits without stripping or damaging the skin. "Acids react with different substances, like metals, salts, and bases, to spark chemical reactions," Dr. Dennis Gross, a dermatologist with a private practice in New York City, explained to Women's Health. "On the skin, it's like dropping a small pebble into a very still pond. The gentle ripples on the water's surface are the acid spreading gentle exfoliation onto the top layer of skin."

Each group of acids offers its own set of advantages, but BHAs — which you might know by other names such as salicylic acid, willow bark extract, and tropic acid — in particular are known to target stubborn, deep-rooted skin issues. "BHAs are organic carboxylic acids that work on skin's surface and deep inside the pore," Orit Markowitz, a New York-based board-certified dermatologist at OptiSkin, revealed to Byrdie. So if clear, radiant, healthy-looking skin seems out of reach, a BHA could be the hero ingredient that'll change your mind.

BHAs fight dull, dead skin

Exfoliation is a skincare step that can benefit almost everyone, but it's an easy step to forget — or overdo. Adding a chemical exfoliant, including BHAs, to your regular routine can ensure you slough away any lingering dead skin cells without risking skin damage. "Chemical exfoliators are often more gentle for sensitive skin," Dr. Elizabeth Houshmand, a board-certified dermatologist, told "AHAs work by melting the glue that attaches the dead skin cells to the outer layer of the skin, while BHAs are oil-soluble ingredients that go deeper into the skin and pores for a thorough cleanse."

So how do you know if your skin is in need of BHA's exfoliating powers? Dullness is a common giveaway, but be sure to look beyond the surface. BHAs like salicylic acid are known to penetrate the skin to exfoliate from within, meaning they're the perfect match for bumpy, congested, and thickly textured skin.

Take a look at your lifestyle and skincare habits too. As Dr. Deirdre Hooper, a board-certified dermatologist from Louisiana, explained to Well+Good, "If your skin's been feeling oily, and you're wearing a mask, and you're clogging up, you're wearing a lot of makeup, and you feel like you've just accumulated debris on your face," you might need some extra exfoliation. If you're not already buffing away dead skin cells with a scrub or piling on other skincare acids, try working a BHA into your regimen.

They're effective at taking down stubborn acne

BHAs are perhaps best known for their ability to clear and prevent acne, which is why you'll notice salicylic acid listed as an active ingredient in numerous over-the-counter acne products. Part of BHAs' acne-fighting abilities has to do with their exfoliating properties, though their potential doesn't stop there. "BHAs are also anti-inflammatory and anti-bacterial, which is really beneficial for certain skin complaints like acne," cosmetic physician ​​Dr. Bibi Maryam Ghalaie shared with Stylist. In other words, BHAs bust existing acne by clearing clogged pores and banishing inflammation, while stopping new spots from forming by killing blemish-causing bacteria.

If this sounds like a lot for fragile skin, rest assured that BHA actives such as salicylic acid are typically considered safe for sensitive skin, as long as they're used in moderation, though you might want to ease up on other acne products first. And because BHAs are naturally anti-inflammatory, you may even find that some of the redness associated with sensitive skin clears up. However, if you have a skin condition such as eczema or rosacea, it's best to consult with your dermatologist before slathering on acids to avoid potential side effects, as WebMD advises.

BHAs might freshen up aging skin

By now, many of us realize that "anti-aging" is a loaded — and pretty problematic — term. Aging is inevitable, so why fight it? Still, the truth is that we may not always be so quick to welcome the ways our skin changes over time. If you're honestly not too fond of that new crease on your forehead or the sunspots that publicize your refusal to wear sunblock during your teen years, BHAs may help.

BHAs' sister acid, AHAs, might be more commonly associated with anti-aging (per Healthline), but BHAs show promise for younger, oily skin that's already showing signs of wear. Though more research is needed to uncover just how much BHAs can help with aging, the U.S. Food and Drug Administration notes that these acids may smooth fine lines and wrinkles, and WebMD suggests that BHAs could improve discoloration and texture caused by sun damage.

When using acids in your skincare lineup, make sure to include SPF too. BHAs can make your skin extra sensitive to the sun, which could negate the anti-aging benefits you're going for. Remember to apply sunblock to your face and body after using products containing BHAs, and reapply every two hours (yes, even if you're wearing makeup) to stay protected.

Are there any drawbacks?

Go through the list of common skin concerns, and BHAs seem to solve most. But even though these mighty acids can do a lot for your skin, they come with a few potential drawbacks worth noting.

First, BHAs aren't ideal for all skin types. For instance, Dr. Michele Green, a dermatologist in New York City, told NBC News that BHAs can irritate and dehydrate dry skin. In general, these actives are more suitable for oily, acne-prone complexions.

You might also experience irritation if you're using other exfoliating or potentially aggravating ingredients, as the combination could be too harsh. One example: retinol. "If your routine contains AHA/BHA in addition to retinol, wait to use your retinol about an hour after AHA/BHA application," dermatologist Dr. Scott Paviol recommended to Today. If you still notice irritation, such as redness or stinging, consider cutting an active from your routine or applying your BHA more sparingly. Additionally, steer clear of products with high concentrations of BHA ingredients (because a higher percentage isn't always better, FYI). As a rule of thumb for salicylic acid, for example, skincare brand Clean & Clear suggests sticking to 2% strength or lower. When in doubt, talk to your doctor to find the right formulations and product combinations for your skin.