It is an antiperspirant. Antiperspirants always contain aluminium salts. Otherwise they would just be deodorants (deodorants only work against the smell of sweat, not against sweat itself), because this ingredient is the only one that really helps against perspiration. And this one has a lot of aluminium salts and alcohol, which is why it is so effective and lasts for days. It's only used every 5th day or so. I tell you, I hadn't found anything that really helped until I found Perspirex Strong in a pharmacy several years ago. It's incredibly good, which is why it's so expensive. But if you're worried about the aluminium, then you can't use an antiperspirant, especially one that contains that much.

Ingredients and instructions for use
Ingredients
Alcohol Denat, Aluminum Chloride, PEG-12 Dimethicone.