Antiperspirants have had aluminum salts as the key ingredient since the very beginning. Aluminum salts aggregate in pores, ultimately blocking sweat from getting through. These are the four most common versions (Al Chloride, format, chloro-hydroxide, & zirconium tetrachlorohydroxide).
A type of sweat gland called the apocrine gland produces sweat which has fats and proteins. Sweat contains lipids and amino acids that get broken down by bacteria. And that process creates a distinctive body odor smell. Bacteria on the skin eat these fats and proteins and produce bad odors. The odor is gross. Deodorants make the environment too acidic or too salty for the bacteria to thrive, thus preventing the production of odors. On the other hand, antiperspirants enter the tube through which the sweat comes onto the skin.
How does antiperspirant work?
Antiperspirant prevents both sweat production and bacterial growth that was invented in 1903. It works by creating a partial vacuum around the armpit which absorbs all things in the general vicinity, particularly smells.
Antiperspirants usually have fragrances and alcohol. In addition to those ingredients, they contain an aluminum compound, usually aluminum chlorohydrate, which reduces sweat. These clog those sweat glands able to prevent sweating.
Both deodorant and antiperspirants often use cyclomaticones. Cyclomethicone is fast drying silicon compounds as solvents. So the chemical formula of it is C10H3O5Si5.
Every hydrogen atom is bonded to a carbon atom, and every single carbon atom has three hydrogen atom bonds and one bond to a silicon atom. Their atomic force is key to stop sweating and bacterial growth.
There are two types of sweat glands all over the skin: Eccrine and Apocrine.
First, there are eccrine glands, most of them, and they kick in to cool. It means that heat, physical exertion, stress, and nervousness can stimulate them. Eccrine glands excrete water and salt and, for the record, have nothing to do with body odor.
Apocrine glands, on the other hand, carry secretions of fat and proteins along with your sweat. Once this hits the exterior surface of the skin, those fats and proteins are a buffet for bacteria that excrete.
Antiperspirants have an active ingredient that gives them their sweat blocking powers, usually an aluminum-based compound like aluminum chloride or aluminum chlorohydrate. When this stuff gets into the duct leading into an eccrine gland, aluminum ions enter the cells lining the walls of the duct.
Water molecules pass into the cells with them. The cells around the duct begin to swell with the water, enough to squeeze the ducts closed. At that point, sweat can’t get out, and you’re stain-free for a while. But each cell can only draw in a certain amount of water. So eventually, the concentrations of water outside and inside the cells reach equilibrium.
When this happens, water inside the cell begins to pass back out of the cell through osmosis. And the swelling goes down, reopening the duct. That is why people have to reapply for antiperspirants.
Also, it acts astringently to cause pores to contract. More importantly, antiperspirants are also trying to help regulate body temperature. Research suggests that even extreme body odor can be reduced through changes in diet and by doing more exercise.