How Does Deodorant Stop Sweat?

It's already been a hot summer with last month being warmer than average. And that means we've been loading up on deodorant.

But how exactly does deodorant stop sweat? And how do you know if you're using it right?

Americans spend more than $2 billion a year on deodorant.

Personally, Jason DeRusha swears by Power Stick.

"It costs 97 cents a stick," he said. "I buy it by the case."

Dr. Charles Crutchfield is a dermatologist in Eagan. He said deodorant is a combination of salts -- the most common being aluminum chloride.

"They actually form little gel plugs in the sweat pores," he said. "The salt, itself, forms some type of a gel, and it's really mysterious. I remember even in residency, no one was quite sure exactly what was going on. They said, this is just what happens. But if you look microscopically, you'll see the gel plugs in the pores."

And deodorants aren't just perfumes. When you sweat, bacteria grows.

"One of the byproducts is DHA -- that's what smells bad. That's the stink," Crutchfield said.

Deodorants actually kill the bacteria, so there's no DHA, and no stink.

Some doctors say the best time to apply is 9 p.m. Your body temperature is cooling so your body absorbs it better.

On Facebook today, Tricia asked if it's safe to put aluminum on your body every day?

There's never been a major study showing a danger and the National Cancer Institute said there's nothing to worry about.