How do you stop hyperhidrosis?

Usually three things, a strong antiperspirant, Botox, and as of recently a select few clothing options.

One of the strongest antiperspirants out there is Mon Ray Antiperspirant. It is recommended by Dermatologist and Pharmacist to be the strongest outside of prescription.
Botox is another option but is costly. It only last four to six months and requires a physician visit. I will be the first to warn you, insurance does not cover this at all. They don't think it is a medical condition.

A great clothing option is Silverback Apparel's two lines of undershirts. They are build with a sweat proof layer to stop underarm and back sweat. They are a great complimentary solution for Botox and Antiperspirant.