Natural and organic deodorants have been growing in popularity at a rate of about 14 percent a year in the United States since 2021, according to a report from Cognitive Market Research.While conventional deodorants and antiperspirants usually use aluminum salts, perfume, and fragrances in their formulations, “natural” or “clean” deodorants use what many consumers consider to be “safe” ingredients, like essential oils and plant extracts. Some use antimicrobial alpha-hydroxy acids (AHAs) like mandelic acid, which has been popularized recently on social media, says Maya Thosani, MD, a board-certified dermatologist with Modern Dermatology in Scottsdale, Arizona.It should be noted that the use of the word “natural” isn’t regulated by the U.S. Food and Drug Administration, so there’s no agreed-upon standard of what that means and whether natural deodorants are better than conventional ones.

Here’s what to know about mandelic acid deodorant.

Mandelic acid deodorant is a product that uses mandelic acid in its formulation, which is an AHA derived from bitter almonds. Mandelic acid offers exfoliating benefits and may treat wrinkles, acne, and sun-related skin damage with less irritation than other AHAs, like glycolic acid. “It also has a wide spectrum of biological activities, including antimicrobial, antiviral, antifungal, and anti-inflammatory properties,” Dr. Thosani says.

Those abilities to fight fungi and other microbes are why people turn to mandelic acid for body odor. “Sweat under the armpits is a perfect environment for bacteria to grow, and that causes the odor,” says Katarina Wijkander, a cosmetic chemist and founder of Chicago-based Sirkka Labs, which formulates and manufactures products for beauty brands.

However, like other natural deodorants, mandelic acid deodorant won’t address sweating, says Michele Green, MD, a board-certified cosmetic dermatologist with a private practice in New York City. Deodorants address odor, while antiperspirants are a separate category of products that use aluminum salts to block sweating.Mandelic acid deodorant is a deodorant but not an antiperspirant, so it addresses only odor and not the sweat itself. To minimize underarm stink, you need to neutralize bacteria. More conventional products often use baking soda and alcohol to cover odors. Mandelic acid deodorant, on the other hand, uses mandelic acid to lower the pH levels of the underarm and make the area less hospitable to bacteria, Wijkander says.

Mandelic acid also exfoliates, which can help reduce odor as well as the bacterial activity on dead skin cells that results in body odor. “Bacteria like dead skin cells, so if you lower the pH and you also exfoliate and remove a lot of the dead skin cells under the armpits, then there’s less of a friendly environment for the bacteria,” Wijkander says.

Other benefits for skin of mandelic acid products may include:

• Improving mild-to-moderate facial acne

• Treating hyperpigmentation (dark patches of skin)

• Increasing skin elasticity and firmness

Thosani says that mandelic acid is gentle and well tolerated, but there is still a risk of irritation, redness, or swelling. “You’re putting something that has an acid right onto your skin, so your skin might get sensitive,” Wijkander says.Dr. Green adds that mandelic acid comes with fewer irritating side effects than other AHAs used in conventional products (such as glycolic acid) because it has a larger molecule size, which means it doesn’t penetrate as deeply into the skin.

Mandelic acid deodorant is for someone looking to embrace more “natural” or “clean” products. That said, it’s worth noting that research hasn’t identified links between conventional aluminum-containing deodorants and breast cancer, despite this being a long-standing rumor.

Mandelic acid deodorant may also be worth a try if you’re allergic to an ingredient that’s found in mainstream deodorants, such as aluminum, fragrance, or baking soda, Thosani says.

But mandelic acid deodorant is not for everyone. For instance, since AHAs are natural exfoliants, some may find them drying or irritating.

“If you have inflamed skin in the underarms from eczema, daily shaving, or razor burn, or extremely sensitive skin, the mandelic acid may be too harsh, since the skin barrier is compromised,” Thosani says.

Anyone with sensitive skin should perform a patch test first by applying a small amount of the product to the inside of your wrist or the back of your ear and checking for any adverse reactions, such as irritation or a rash, Green says.

Green adds that these deodorants also might not be great for someone with excessive sweating (hyperhidrosis) or people who live in hot and humid climates, since mandelic acid deodorants don’t offer antiperspirant benefits. “When sweat production increases, the acid’s effectiveness can be compromised because it may be diluted or washed away by perspiration before it can work,” Green says.

Finally, it’s best to avoid mandelic acid deodorant if you have an almond allergy, Green says.

If you’re interested in giving mandelic acid deodorant a try, consider these tips:

• Apply to dry skin and wait for it to absorb before getting dressed. “This prevents dilution and helps the formula work at maximum efficacy,” Green says. Waiting about two minutes is a good rule of thumb.

• Avoid products with high mandelic acid concentrations of near 10 percent, as that will increase the risk of irritation, Wijkander suggests.

• Don’t layer an antiperspirant over it. “That might change the pH, and then you lose the effect that you want,” Wijkander says. Opt for a deodorant featuring a natural absorbent, like tapioca starch, instead, she says.

• If you have sensitive skin, moisturize with a thick moisturizing cream before applying mandelic acid deodorant, to minimize irritation, Thosani says. If the skin becomes irritated, stop using the product and apply a healing ointment such as Aquaphor or Vaseline as the skin recovers, she adds.

• Do not shave the area right before or after applying, to avoid extra irritation, Green says.

• Give it time to work. “If you’re using it consistently, then you’re creating a new environment in the armpit over time,” Wijkander says. The product you use, such as an antiperspirant versus a deodorant, affects the microbiome of the underarm. “It usually takes a while for the body to adjust, so don’t expect it to be perfect after one or two days,” adds Wijkander. Brinkley says that you can expect to see maximum results within two to three weeks.

• Mandelic acid deodorant is a type of natural deodorant that uses this alpha-hydroxy acid to reduce odor by making the area less friendly to bacteria.

• In addition to fighting odor, mandelic acid has antimicrobial, antiviral, antifungal, and anti-inflammatory properties, and it may offer benefits that improve skin elasticity, help with exfoliation, and treat acne and hyperpigmentation.

• Since it uses an acid, this deodorant comes with a risk of irritation, redness, and swelling, though mandelic acid can be less irritating than other AHAs. Mandelic acid deodorant works to block odor but does not offer antiperspirant benefits, so it’s not a great option for someone who sweats a lot.