Function

• The function of an antiperspirant is quite simply to prevent the user from sweating, and thus developing unpleasant body odor. Antiperspirants work by stopping sweat in the area of application, which is most typically the underarms, by applying aluminum ions that cause the sweat glands to close up and prevent the excretion of sweat. This leads to reduced odor because the cause of odor are otherwise harmless bacteria present on the skin that tend to proliferate in warm, damp, low oxygen conditions -- such as sweaty armpits. By blocking sweat, the conditions are not nearly as damp, so antiperspirants together with deodorants tend to control body odor fairly well.
  
  

Time Frame

• Many antiperspirants begin to work immediately after application. Different products last a different amount of time, but most sold on the market aim to last at least a day or until the next time the individual takes a shower.
  
  

Misconceptions

• Antiperspirants are not the same thing as deodorants. Deodorants act against or prevent the odors from the bacteria that grow in the underarms, but antiperspirants are specifically aluminum-based compounds that work against sweat. It is possible to buy deodorants that do not contain antiperspirants. In addition, it is a common misconception that sweat itself is what causes odor when it is actually the actions of the bacteria that cause the odor; sweat is only a factor because it tends to play a role in creating the correct conditions for the bacteria to proliferate.
  
  

Theories/Speculation

• There have been a number of Internet rumors about health risks associated with deodorants with antiperspirants, particularly because the main ingredient in antiperspirants happens to be aluminum. Some of these theories speculate that the constant intake of aluminum into the body could be a contributing factor to Alzheimer's Disease, which has been associated with aluminum deposits in the brain. Others speculate that by blocking the excretion of sweat in the underarms, antiperspirants could be a contributing factor in breast cancer. Although interesting, these theories are merely speculation and have not been substantiated by facts -- and one study in particular examined this theory and found no increased risk of breast cancer in antiperspirant users compared to non-antiperspirant users.
  There was one study that found antiperspirants and deodorants might cause buildup of potentially harmful ingredients in breast tissue, and this study is commonly cited by people who are against antiperspirant use, but it is important to point out that this study did not show that these ingredients were a causal factor in cancer. Many scientists have called for more research, however, and at present the idea that antiperspirants cause adverse health effects remains mere speculation -- although many argue that a theoretical risk should not be ignored.
  
  

Considerations

• Although there is no proof of commercial antiperspirants causing any adverse health effects, if you are concerned you can use deodorants without antiperspirants (many natural deodorants fall in this category) or you can attempt to use natural alternatives to antiperspirants, such as baking soda or salt-based products that work by suppressing the bacteria in the underarms rather than preventing sweat.