Until human perspiration or sweat is fermented by bacteria that grow in hot, humid environments, it is largely odorless. Bacterial breakdown of perspiration occurs in armpits, feet, and other areas of the body. The human underarm is warm and the sweat glands provide moisture, making it an ideal location for bacterial fermentation. Antiperspirants tackle wetness; deodorants tackle odor. Deodorants are classified and regulated by the FDA and are considered cosmetics. If the deodorants are combined with antiperspirant agents, they are classified by the FDA as drugs.
Deodorants address the sweat glands that cause odor by using formulas that eliminate or mask that odor. They often provide an additional scent, and there are some products that address both odor and wetness. Antiperspirants are applied to the underarm, and should be applied at night before bed when people are sweating the least. Deodorants may be used on the feet and other areas of the body as well as the underarm. They are applied after a morning shower.
There is a myth that if you cannot smell the deodorant, it is not working. Women frequently apply deodorant several times during the day. They carry the deodorant in their car, in a purse, or at work. Most shoppers consider that a product’s scent is a sign that it is effective. Scent is not an indication of whether the product has failed. It can still be battling odor and wetness even if a person cannot smell it.
Many people are concerned about aluminum, the active ingredient in many antiperspirants, but studies do not give clear answers. Natural deodorants are increasing in popularity and may be more expensive. There are over-the-counter products labeled as “natural deodorant crystal” and contain potassium alum or ammonium alum. Unfortunately both alums also contain some aluminum. Deodorants and antiperspirants are available in a stick, cream, or a spray.