Top Dermatologist: Glycolic Acid Is the Deodorant Dupe You Never Knew You Needed

Glycolic acid is a star ingredient in skincare for its ability to slough off dead skin cells, reverse sun damage and combat acne, scars and dark patches. Now, a new movement on social media is shining the spotlight on the trendy skincare ingredient for a different reason: glycolic acid for underarms is said to fight stinky, sweaty armpits.  In fact, the hashtag #glycolicacidasdeodorant has amassed more than 30 million views on TikTok and counting, with users claiming that it does everything from combat sweat and odors to reverse armpit skin discoloration.

“This trend comes as a part of a movement away from traditional antiperspirant options and a long history of glycolic acid’s safety and effectiveness,” says Richard Bottiglione, MD, board-certified dermatologist and founder of glycolic-based skincare line Dermatologist’s Choice Skincare. “This is why glycolic acid has been the flagship ingredient in skincare lines for decades because it has stood the test of time,” he says.

So, what exactly is this magical skincare ingredient? Read on to learn about glycolic acid and if it can really do what deodorant can.

What is glycolic acid?

Glycolic acid is an alpha hydroxy acid (AHA), which is a class of water-soluble acids widely used in skincare products. It is naturally derived from sugar cane and belongs to a group of organic fruit acids known for their exfoliating properties. Glycolic acid is the smallest AHA in molecular size. “Due to its small molecular size, glycolic acid is uniquely able to penetrate the skin’s pores, allowing it to go the deepest of any of the alpha hydroxy acids,” says Dr. Bottiglione. “This property makes it more potent in promoting skin renewal than other AHAs,” he adds. (*Important to note there are two types of glycolic acid, active non-neutralized glycolic and neutralized glycolic acid. Dr. Bottiglione is referring to the active non-neutralized glycolic.)

Glycolic acid is a common ingredient in various skincare products, including cleansers, toners, masks and creams. It’s used in different concentrations, depending on the product and the desired effect (for example, a chemical peel uses a higher concentration of glycolic, such as 30%).

What are the skin benefits of glycolic acid?

Glycolic acid loosens the bonds between the dead skin cells that give a dull appearance to the skin’s surface. By doing this it promotes shedding of the dead cells, helping to reveal newer, smoother skin underneath. Studies suggest that glycolic acid may also stimulate the production of collagen, a protein that provides structure to the skin, which can contribute to improved skin elasticity and firmness. (Click here to learn more about collagen.) Glycolic acid is often used to treat hyperpigmentation, such as dark spots and age spots, by promoting the shedding of pigmented skin cells and encouraging the growth of new, evenly pigmented skin. It is also used to treat acne due to its exfoliating properties.

What are the benefits of glycolic acid for underarms?

It can stop odor

First, Dr. Bottiglione says it is essential to understand the root causes of armpit odor. “Armpit odor is the result of sweat, moisture, dirt and bacteria accumulated underneath the armpits,” he states. The two traditional ways to fight underarm odor? Antiperspirant and deodorant. Antiperspirants eliminate sweat production, whereas deodorants use fragrance to mask the smell. Glycolic acid’s chemical makeup allows it to kill odor-causing bacteria — which means it can sub in for your favorite deodorant because it stops the smell before the need to mask it with fragrance.

But doctors say it’s important that it’s in its most concentrated form. “When glycolic acid is added to skin care products, it is mixed with other ingredients and, as a result, can become diluted, and the pH is neutralized. Research shows that neutralizing glycolic acid pH decreases its antibacterial properties; therefore, it is crucial to look for non-neutralized glycolic acid products if you want them to fight armpit odor,” advises Dr. Bottiglione.

It can reduce bumps and brighten underarms

Because of its exfoliating properties, glycolic acid is also an effective ingredient in many products that fight razor bumps and ingrown hairs. It’s also effective in fighting hyperpigmentation, which will lighten skin discoloration in the areas it’s applied.

One caveat: “Glycolic addresses the dirt and sweat build up in the pores and kills odor-causing bacteria accumulated underneath the armpits, but on its own won’t stop sweating,” says Dr. Bottiglione, especially if you sweat a lot and need something more heavy-duty. He recommends an aluminum-based antiperspirant like Drysol (Buy from Amazon, $36.99) or Certain Dri (Buy from Amazon, $9.02) in this case.

Or you can add sweat absorbing powders to the mix like corn starch or arrowroot powders, or bentonite clay like Molivera Organics Bentonite Clay for Detoxifying and Rejuvenating Skin and Hair (Buy from Amazon, $12.95), commonly used for sweaty feet.

Missing the scent? Dr. Bottiglione says just mix in a few drops of your favorite essential oils, and voila, homemade deodorant!

This YouTube video from OHEMAA shows the excellent results of using glycolic acid on the armpits for six months.

How do I use glycolic acid on my underarms?

While there are products containing glycolic acid that are designed for underarm use like Bella Skin Probiotic Underarm Toner (Buy from Bella Skin Beauty, $27.50) or Forgotten Skincare The Original Deodorant Brightening Cream (Buy from Forgotten Skincare, $44), you can simply soak a cotton pad with the glycolic acid of your choice and swipe it onto your underarms after you shower. Doctors say it’s essential to look for a formulation that’s less than 10% glycolic to avoid irritation but if you experience any adverse effects, it’s best to discontinue use, try something with a lower concentration of glycolic or use it less frequently.

What glycolic acid products can I try on my underarms?

While The Ordinary Glycolic Acid 7% Exfoliating Toner (Buy from Sephora, $13) seems to be the current cult fave, there are others on the market you can try if you want to ditch your current deodorant and go the glycolic acid route.

Dermatologist’s Choice Glycolic Peel Cleansing Pads (Buy from Dermatologists Choice, $65)

Dr. Bottiglione recommends his glycolic cleansing pads, made with active, non-neutralized glycolic acid.

Kiehl’s Ultra High-Potency glycolic serum (Buy from Ulta, $35)

Kiehl’s glycolic serum has 9.8% glycolic acid and is touted to spot treat rough and discolored areas of the face and even cracked heels.

Mario Badescu Glycolic Acid Toner (Buy from Amazon, $12.83)

Mario Badescu combines glycolic acid with aloe vera, which may be a better choice if you have sensitive skin, as does L’oreal’s Revitalift drugstore version (Buy from Walgreens, $34.99)

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