Aluminum chlorohydrate is an astringent that is used as a topical antiperspirant or body deodorant. Although it's the least irritating of the aluminum salts, it can still result in allergic reactions. But here's where it gets stickier: Aluminum also happens to be a neurotoxin that alters the function of the blood-brain barrier, linking it to Alzheimer's disease and cancer. We don't have any conclusive proof, however, that antiperspirants actually increase your risk of getting Alzheimer's.
Still, some research suggests that aluminum-based compounds, which are applied frequently and left on the skin near the breast, may be absorbed by the skin and result in estrogen-like behavior. Because the hormone has been known to promote the growth of breast-cancer cells, some researchers have suggested that aluminum-based compounds in antiperspirants could contribute to the development of breast cancer. Other doctors, on the other hand, think that the antiperspirant-cancer link is a lot of bunk.
The bottom line? We'd avoid if whenever we could, but we wouldn't sweat it too much, either.
Difficulty level: Easy