According to the Federal Drug Administration (FDA), cosmetics that are intended to treat any condition, including preventing perspiration, are regulated and standards for safety are required to be met. Antiperspirants, for instance, must meet guidelines for safety before being sold or manufactured in the United States.
Regular deodorants that are not antiperspirants may not be regulated by the FDA specifically, but the ingredients used in making deodorants must be approved by the FDA. Products with ingredients that are deemed unsafe by the FDA are considered adulterated and cannot be sold within the United States.
Although there has been controversy over the link to some specific diseases with the use of aluminum and parabens in antiperspirants and deodorants, WebMD states that these health conditions are the result of a combination of factors. Some people may be allergic to ingredients used in cosmetics, including deodorant, but most people can use it safely.