What's in deodorant & Antiperspirant, and how does it work?
Deodorants reduce odor-causing bacteria and mask smell; antiperspirants use aluminum salts to temporarily plug sweat ducts.
Why sweat smells
Fresh sweat is nearly odorless; skin bacteria break down compounds in apocrine sweat into smelly molecules.
Aluminum claims
The American Cancer Society and NCI report no convincing evidence linking antiperspirants to breast cancer.
Evidence & sources
There is no convincing evidence linking antiperspirants or deodorants to breast cancer. Evidence: moderate. Known: Reviews of available studies. Unknown: Research is limited in size. Source: US National Cancer Institute, Antiperspirants/Deodorants and Breast Cancer (Current revision).