BOTOX® neurotoxin used in a hyperhidrosis treatment helps control the symptoms of severe underarm sweating when topical medicines don’t work well enough. The hyperhidrosis treatment with Botox works by temporarily blocking the chemical signals from the nerves that stimulate the sweat glands. When the sweat glands don’t receive chemical signals, the severe sweating stops. The sweat doesn’t go anywhere else simply because the sweat is no longer produced in the treated areas. After the hyperhidrosis treatment with Botox, the rest of the body is free to produce moisture normally.