How do antiperspirants keep you from sweating?

Actress Cameron Diaz says she hasn't worn antiperspirant in 20 years. Wonder if folks can tell.
Actress Cameron Diaz says she hasn't worn antiperspirant in 20 years. Wonder if folks can tell.
© Nancy Kaszerman/ZUMA Press/Corbis

At the premiere of her 2014 movie "The Other Woman," actress Cameron Diaz garnered a lot of media attention — not so much for her role in the film, but for a startling admission about her personal hygiene.

"I don't believe in antiperspirant," explained Diaz in an interview with E's Marc Malkin. "It's really bad for you. I haven't used it for almost 20 years." Instead, she argued, people should just "let it go and trim your armpit hair so that it doesn't hold onto the scent."

The Huffington Post, one of the publications that jumped on this momentous scoop, snarkily noted that Diaz's avoidance of antiperspirant might explain those red-carpet photos of her with conspicuous sweat stains, as well as persistent gossip that she might have "issues with body odor" [source: Marcus].

But while the Hollywood star might blithely spend her days sporting au naturel armpits, most of us aren't so self-confident about our body's natural cooling mechanism and the aroma it can cause, if allowed to operate unhindered. More than 90 percent of American teens and adults use sprays, solid stick or roll-on products containing antiperspirants (which limit perspiration) or deodorants (which mask its aroma), according to a 2012 study by Mintel, a market research firm [source: MarketingInsight350]. We're so obsessed with preventing sweat stains and stinky armpits that it's become an $18 billion industry worldwide [source: Everts].

However, since most people don't engage in activities where they work up a sweat, dermatologists say that we don't need as much antiperspirant as we think. Bathing and changing clothes regularly will reduce the presence of the bacteria that create body odor [source: Toedt et al.] Dermatologist Dr. Jeanine Downie even told The New York Times that most people would "probably be fine just using a little powder."

It's safe to say that the science that prevents us from becoming sopping wet is a mystery to most of us who aren't chemists. But there's no need to break a sweat about it. In this article, we'll explain how antiperspirants inhibit perspiration.