The invention encompasses a method for treating hyperinsulinemic type 2 diabetes by local administration of a neurotoxin, such as a botulinum toxin, into the pancreas, thereby reducing insulin secretion from a B cell, and a method for treating hypoinsulinemic type 2 diabetes by local administration of a neurotoxin, such as a botulinum toxin, into a sympathetic ganglion, thereby reducing an inhibitory effect upon insulin secretion.