Oxybutynin
"This is an actual life changer for me. I've been abnormally sweaty as long as I can remember - small walks in any kind of warmth I'd be soaked, even shovelling snow in (actual) single digit temperatures would result with me soaking through  coats. It would get 10 fold worse in any area with humidity (I live in a very high altitude/dry area). I was very self conscious of this, constantly only had my hair back because it would be wet by mid day. Miserable. I started doing some looking into the symptoms and found hyperhidrosis and was so relieved to see something with a name and a potential relief. I immediately set an appointment with my doctor to discuss Oxybutynin. I've been on it for three days and my sweating is gone. It's GONE."