Think of the procedure as tiny ant bites, but over 20-25 on each armpit. It usually inject both arms at the same time to speed up the process. In the scheme of things, 95% of patients tolerate the procedure without any problems, but some find it painful. Remember pain is very subjective.
This is how I deal with things- if you had the procedure before, or if you have a low pain threshold (nothing to be worried about), come in 30 minutes early and sit you in a quiet room with some 23/7 gel on. This takes away 80% of the pain, and in some cases 100%.
Pain is the least problematic stumbling block of getting Botox for excessive sweating.
Regards
Dr. Davin Lim