For the past couple of years, a trend has been making the rounds on social media: skip the deodorant and put glycolic acid on your underarms instead. The creators pushing it say it cuts body odor, brightens the area, and leaves the skin smoother and more comfortable while it’s at it.
So can a bottle of glycolic acid actually replace deodorant? Is this another TikTok trend with nothing underneath it, or is there real science here?
We went looking.
First: why does sweat smell at all?
Here’s the part that surprises most people.
Sweat itself has almost no odor.
What your sweat glands produce is mostly water, salts, and minerals. What we recognize as body odor only shows up once that sweat meets the bacteria living on the skin’s surface.
The underarms contain apocrine glands, which secrete a fluid richer in proteins and fats. The bacteria in that area break those compounds down and produce the volatile compounds responsible for the characteristic smell.
So the sweat isn’t what smells. What bacteria make out of it is.
So what does deodorant actually do?
Most people assume deodorant stops you sweating. These are two different products.
Deodorant is built to reduce odor, through a combination of fragrance and, sometimes, antibacterial ingredients that cut bacterial activity.
Antiperspirant typically contains aluminum salts, which temporarily reduce how much sweat your glands produce.
So if you want less sweat, antiperspirant is the product. If you want less odor, there are several approaches on the shelf now, and glycolic acid is one of them.
So why glycolic acid specifically?
Glycolic acid is one of the best-known AHAs in skincare.
At the right concentration, it lifts away dead skin cells, encourages renewal, and leaves the surface smoother and more even.
It does something else, too.
It makes the surface of the skin more acidic.
Some of the bacteria responsible for body odor don’t thrive in that environment, which is why some people see less odor when they use glycolic acid consistently.
It’s part of why The Ordinary’s Glycolic Acid 7% Toning Solution became one of the most viral skincare products of the past few years - despite never being intended as a deodorant.
Does the science actually back this up?
This is where precision matters.
There are plausible biological explanations for why glycolic acid might reduce body odor in some people, and there are plenty of positive personal reports out there.
But as of now, there aren’t enough solid clinical studies to say glycolic acid can replace deodorant for the general population.
To put it plainly:
- There’s a plausible mechanism.
- There’s positive anecdotal experience from a lot of users.
- But there still isn’t enough evidence to present it as a universal solution.
Who might this be worth trying for?
Glycolic acid might be especially interesting for people who:
- Want to cut back on fragranced products.
- Don’t struggle with excessive sweating.
- Want to reduce body odor specifically.
- Are also interested in improving the skin texture of their underarms.
If you deal with excessive sweating, though, glycolic acid alone isn’t going to solve it. It doesn’t reduce sweat production.
What about dark underarms?
This is a big part of why the trend took off in the first place.
Because glycolic acid lifts dead skin cells and encourages surface renewal, it can gradually improve the look of superficial darkness caused by friction or dead-skin buildup, for some people.
Not all darkness is the same, though, and not every kind of hyperpigmentation responds the same way. If the darkness comes from a medical issue, a hormonal condition, or a specific skin condition, it needs a proper diagnosis, not a cosmetic product.
Can you use it on other parts of the body?
Some people also use glycolic acid on:
- Elbows.
- Knees.
- Areas prone to friction.
- The bikini line (with real caution, and avoiding mucous membranes).
The goal in those cases is usually texture, or the look of darkness.
Same rule applies: ease in gradually and watch how the skin responds.
How to use it correctly
If you want to try it:
- Start with a frequency of twice a week.
- Apply to clean, dry skin.
- Avoid using it right after shaving, waxing, or epilating.
- Stop if you notice stinging, irritation, or significant peeling.
- Don’t combine it with other acids or retinoids on the same area the same evening.
For a lot of people, underarm skin is more delicate than facial skin. Start slow.
Is it right for everyone?
No.
Anyone with especially sensitive skin, active eczema, or irritation in the underarm area should be extra careful. Skin is also more reactive right after shaving, so wait before you apply.
If you get significant stinging, ongoing redness, or irritation, stop.
Bottom line
Glycolic acid is not “the new deodorant,” and it isn’t right for everyone.
There is, though, a reasonable biological explanation for why it might reduce body odor in some people by changing the environment on the skin’s surface - and it can improve skin texture at the same time, and in some cases help with the look of superficial darkness.
If you don’t struggle with excessive sweating, you want a fragrance-free alternative, or you’re just curious about the trend, it may be worth trying. Ease into it gradually and pay attention to how your skin responds.
As with most skincare trends of the past few years, separate what people report online from what’s actually been proven in research. Some of these trends turn out to be genuinely worthwhile; some only work for some people. With glycolic acid, the honest answer lands somewhere in between.
This article is intended as general information and is not a substitute for professional diagnosis or treatment from a licensed dermatologist.
