Our Dermatologists Explain Everything You Need to Know About Armpit Sweat, Smells and Stains
It’s summer in the Northern Hemisphere which means you’re likely sweating up a storm whenever you’re outdoors. But while some guys dislike armpit sweat and odor, others love it or avoid using antiperspirants and deodorants for fear of getting underarm stains on their favorite shirts. So what’s a guy to do? We interviewed Dr. Terrence Keaney, a dermatologist who specializes in men’s skin, and consulted other experts to help you stop fearing underarm sweat, smells and stains.
Are underarm sweat or smells unhygienic?
Sweat is merely how the body stays cool in hot weather, and if your body didn’t have a way of cooling itself off, we’d all have seizures from overheating, says Dr. Constantine George, an internal medicine specialist.
While underarm odor may offend some noses, the odor doesn’t come from sweat and a piquant armpit doesn’t mean that a person is unwashed or “dirty.” It just means that a person has a larger amount of microscopic organisms called corynebacterium living in their armpits.
We all have corynebacterium living in our armpits and crotches. In fact, evolutionary biologists believe that the specialized “apocrine” sweat glands in the armpits and crotch work together with corynebacterium to create a personal scent that helps humans attract and mark their sexual partners.
Corynebacterium turn the fats and proteins in our sweat into chemical compounds that have “a particular pungent odor,” says dermotological researcher Dr. Chris Callewaert.
The longer you go without washing your armpits, the stronger these odors become. Certain foods can alter your odor,Dr. George says, but odor alone doesn’t indicate uncleanliness, even though many people think so.
Are antiperspirants and deodorants bad for the body?
Dr. Keaney says, “There is strong evidence to show that antiperspirants and deodorants are safe and do not cause long term health problems.” He’s right. Although some people worry that their chemicals might cause degenerative diseases, there’s no medical evidence to support this worry.
Most deodorants work by making your armpit too salty or acidic for odor-causing bacteria to survive. Many antiperspirants double as deodorants by using chemicals like aluminum and zirconium to literally clog your underarm’s sweat glands. Without sweat, bacteria can’t create stinky compounds.
In order for the chemicals in antiperspirants and deodorants to harm you, you’d have to consume massive quantities rather than lightly smear them under your pits.
And yet, amid the hundreds of different deodorants and antiperspirants, Dr. Keaney says the “right” one to use “really comes down to your personal preference.”
“If odor is a problem, use a deodorant. If sweating is an issue, use an anti-perspirant,” he says. Same with spray versus roll-on antiperspirants and deodorants.
Which antiperspirants and deodorants reduce stains on clothing?
If you’re trying to avoid armpit stains on your favorite shirts, the usual culprit is aluminum chloride, a common ingredient in antiperspirants that temporarily clogs sweat glands. It’s also acidic which contributes to stain production.
While Dr. Keaney suggests Dove Men+Care Stain Defense Antiperspirants, which contains a masking oil to prevent clothing stains, a few other brands like Arm & Hammer also sell non-stain versions. It’s also wise to only use a thin layer of deodorant or antiperspirant rather than caking it on — using less will result in fewer stains.
Nonetheless, some antiperspirants and deodorants can still cause skin irritation or even an unfamiliar armpit smell. If you’re having trouble with either, Dr. Keaney advises you see a board-certified dermatologist.