Botox works to stop sweating the same way it works to control wtinkles. It essentially works as an anti-cholinergic. It inhibits the binding of acteylcholine to its intended target, in this case the eccrine  gland.

    It is recommended that 50 units of Botox be administered into each axilla.  Many of us will use Lidocaine to diminish the pain. Also, if one uses a separate 31 gauge needle, the pain is less than allergy testing. 

    I am not sure if other physicians who adminster this feel the same way, but I have had much longer lasting results when I dilute 2 cc  than the recommended 4 cc's. When done in this manner, the reulsts last 9 months, compared to 4-6 months the Allergan prescribed way.

    Finally, I would like to mention that this is usually a covered service if one other means of treatment has failed ( usually Drysol but sometimes the anitcholinergic Robinul).