AHA vs. BHA: We Asked a Dermatologist to Explain the Difference Once and for All

Is it just us or is the skin-care term “acids” a little scary? Not to mention, with the different varieties (AHA vs BHA), it’s a little confusing, too. We tapped board-certified dermatologist Dr. Shari Sperling of Sperling Dermatology in Florham Park, New Jersey, to explain their differences and tell us exactly what they do, once and for all.

So what exactly are AHAs and BHAs?

“Both AHAs and BHAs are acids that help to exfoliate the skin,” Dr. Sperling explains. “AHA stands for alpha hydroxy acid and comes most commonly in the form of glycolic acid and lactic acid. Because AHAs are water-soluble, they don’t penetrate far into the skin. Meaning they’re more superficial and help remedy surface-level concerns like anti-aging, acne scarring and pigmentation issues.” Dr. Sperling continues, “BHA stands for beta hydroxy acid, or salicylic acid as we know it. Thanks to its oil-soluble makeup, BHA penetrates deeper into the skin providing antibacterial and anti-inflammatory properties. BHAs are great for treating blemishes and acne-prone complexions.”

How do you know which acid to choose?

Although both AHAs and BHAs are acids, they’re used for different concerns. As Dr. Sperling explained, AHAs have an exfoliative effect, which helps to break the bonds between old skin cells so they can easily make way for new, healthy cells. AHAs also stimulate collagen production to help reduce the appearance of fine lines, wrinkles and hyperpigmentation. If you have dry, dull skin, AHAs are a great way to exfoliate the top layer of skin without further drying it out.

BHAs sink into skin to clean out excess sebum from pores and help to remedy blemishes, acne and an overproduction of oil. This explains why most over-the-counter acne products include salicylic acid—and why we all have likely heard of it before. So if you have oily, acne-prone skin, BHAs are probably for you.

Is it safe to use AHAs and BHAs together?

Yes! Many products already contain a combination of both AHAs and BHAs. It’s especially beneficial to use them together if you suffer from cystic acne or have generally acne-prone skin and need to address scars from old blemishes while preventing new pimples from forming. The combination is also great for those of us in the 30-plus crowd that suffer from adult acne or oily skin and want to simultaneously address fine lines and wrinkles.

How often should you use AHAs and BHAs?

At the risk of potentially over-exfoliating your skin, AHAs should be used every other day at the most. Think about it: You don’t want to strip fresh, new skin cells day after day (ouch). For concerns like cystic acne, BHA is safe to use every day to help regulate oil production and keep painful blemishes from appearing.

Dr. Sperling recommends using both acids at night after cleansing and toning, because they increase sensitivity to sunlight. During the day, you should be extra diligent with SPF to protect those new skin cells from UV damage.

Can everyone use AHAs and BHAs?

Yep! Even those with sensitive skin can benefit from AHAs and BHAs. Just make sure you start with a product that says it's suitable for sensitive skin and only use it every few days. Assuming no irritation occurs, you can work your way up to using it every day.

Ready to get glowing? Shop Dr. Sperling’s and our AHA and BHA picks below.

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Dr. Sperling’s picks

Paula’s Choice 2% BHA Liquid Exfoliant 

The main reason why Dr. Sperling loves this product? “It helps to decrease redness associated with blemish-prone skin,” she says. Sold.

Buy It ($36)

Murad AHA/BHA Exfoliating Cleanser

If you don’t want to fuss with extra topical treatments, Dr. Sperling recommends this cleanser, saying, “It combines both AHAs and BHAs (salicylic, lactic and glycolic acids) to help remove dead skin without the need for extra skin-care steps.”

Buy It ($40)

Drunk Elephant T.L.C. Framboos Glycolic Night Serum

When you want all the acids, Dr. Sperling praises this serum, saying, “It contains an AHA/BHA blend of glycolic, lactic, tartaric, citric and salicylic acids to gently exfoliate the top layer of skin while addressing deeper problems. A smoother, more radiant complexion is yours by morning.”

Buy It ($90)

Editors’ picks

Herbivore Botanicals Blue Tansy Mask

If you thought AHAs and BHAs might be irritating, think again. This mask is actually cooling on contact to help soothe angry skin, while gently exfoliating skin to unclog pores and leave skin feeling renewed.

Buy It ($48)

Sunday Riley GOOD GENES All-In-One Lactic Acid Treatment

Multiple PureWow editors hoard this stuff for it’s skin-glowing and hydrating benefits. Gentle lactic acid sloughs away dead skin, while the creamy consistency keeps skin moisturized.

Buy It ($105)

Juice Beauty GREEN APPLE Peel Full Strength

A mix of AHAs and BHAs help to achieve a more even tone and texture while grapeseed extract adds the benefit of antioxidant protection.

Buy It ($48)

REN Clean Skincare Ready Steady Glow Daily AHA Tonic

Swipe this toner on before applying your moisturizer to hit skin with a gentle dose of resurfacing lactic acid and brightening azelaic acid.

Buy It ($35)

Sanitas Skincare Brightening Peel Pads

Chock-full of AHAs, these face wipes deliver the perfect amount of exfoliation at home or on the go.

Buy It ($74)

SkinMedica AHA/BHA Exfoliating Cleanser

As Dr. Sperling mentioned, AHA and BHA cleansers are a great way to get in your resurfacing without the need for added topical treatments. This one includes soothing lavender extracts to reduce inflammation.

Buy It ($47)

SkinCeuticals Glycolic 10 Renew Overnight

Let your acid do all the work while you sleep with this overnight mask. Made with 10 percent glycolic acid plus 2 percent phytic acid, it’s clinically proven to promote a clearer complexion with zero effort on your part.

Buy It ($80)

Dr. Dennis Gross Clinical Grade Resurfacing Liquid Peel

You could get a pricey peel in a dermatologist’s office. Or you could use this peel-in-a-bottle instead. Dr. Dennis Gross bottled his signature in-office treatment for convenient use at home. Plus, it takes only two minutes to dissolve dead cells and reveal radiant skin.

Buy It ($95)

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