What's in Your Antiperspirant?

Medically Reviewed by Laura J. Martin, MD on July 05, 2012
3 min read

The 2 million to 4 million sweat glands in our bodies pump out several liters of perspiration every day, which probably explains why close to 100 million of us report that sweating is "sometimes" or "often" a problem. A Harris Interactive Poll found that excessive sweating negatively affects confidence, careers, and social lives -- not to mention doing a number on clothes.

Antiperspirants are the No. 1 defense against excessive sweating, but how well a product works for you depends on many factors, including its ingredients, the strength of those ingredients, how much you perspire, and even when you apply it.

"You want your underarms to be as dry as possible so that the antiperspirant's active ingredients have a chance to do their job by seeping into pores and plugging sweat ducts," says David Pariser, MD, professor of dermatology at Eastern Virginia Medical School in Norfolk.

If your armpits are damp -- as they are after you towel off from a shower -- the antiperspirant will mix with that wetness and slide off your skin instead of into the sweat ducts where you need it most. That's why it's best to apply antiperspirant at bedtime, when your underarms are dry and you've got about eight hours of relatively sweat-free slumber to allow the aluminum ingredient in antiperspirants to go to work.

Here's the information on the key antiperspirant ingredients you need to combat excessive sweating and feel fresh all day.

Aluminum. Aluminum-based compounds are the most widely used active antiperspirant ingredient because they effectively plug up sweat ducts to temporarily stop the flow of moisture to the skin. Over-the-counter clinical strength antiperspirants contain higher concentrations of aluminum.

Rumors have circulated on the Web for years that aluminum in antiperspirants can raise one's risk of breast cancer and Alzheimer's disease if the compounds are absorbed through pores or enter the skin through a shaving nick. However, "There's no scientific evidence to suggest that antiperspirant ingredients pose any sort of health risk," says Pariser. "These are urban legends that people keep perpetuating through emails."

Parabens. These preservatives help keep cosmetic products free of bacteria. However, several small studies found traces of parabens in breast cancer tumors, suggesting that they may have weak estrogen-like effects if absorbed through the skin. But the study didn't find that parabens caused breast cancer, or that the parabens were from antiperspirants.

Most major brands of antiperspirants are paraben-free these days, though the preservative is still found in some products such as makeup, moisturizers, shaving products, and hair products. If you'd prefer to avoid parabens, check your antiperspirant's ingredients list for words ending in "-paraben," such as methylparaben or propylparaben.

Fragrance. Perfumes are often used in antiperspirants and antiperspirant-deodorant combos to mask body odor. Plus, studies suggest we associate pleasant fragrances with feelings of cleanliness.

"One of the first things people do when shopping for antiperspirants is smell them," notes Pariser. If you have sensitive skin, you may want to choose one without a scent.

Emollient oil. Without some sort of moisturizer like castor, mineral, or sunflower oil mixed into antiperspirant ingredients, the product wouldn't roll or glide on smoothly. These emollients also keep the product from flaking once it dries on your skin.

Alcohol. Aluminum compounds and other active antiperspirant ingredients are often dissolved in alcohol because it dries quickly and feels cool when applied to skin. Alcohol is typically found in roll-ons and aerosols, as well as some gels.

PEG Distearates. Polyethylene glycol (PEG) distearates are emulsifying agents found in many cosmetic products including antiperspirants. This antiperspirant ingredient makes it easier to wash off the product.

Butylated hydroxytoluene (BHT). BHT prevents or slows the deterioration of antiperspirant ingredients once they're exposed to oxygen.

Talcum powder. Absorbs moisture and oil, protects the skin by reducing underarm friction and chaffing, and helps skin feel dry.