How Many Units of Botox Are Needed to Prevent Sweaty Palms?

You can always tell whether there is a definitive answer in medicine when everyone answers the same way. And if you get lots of different answers, you know that the jury is still out. A couple of years ago, I reviewed your question for my own needs. The bottom line is that the best starting dose is 50 units per palm.
Dilution was not critical, but most studies use either a 4 cc dilution or a 5 cc dilution. Any dose less than that, and you may suffer from incomplete resolution or compromised duration. I also appy a topical anesthetic cream to the area for a half an hour prior, which makes it quite tolerable.
The largest body of literature supports the numbers mentioned above. And as Dr Lupo notes, some patients may still need a little more but it is rare. And in fact has not happened in my practice thus far.

Botox injections can be applied to the palms for hyperhidrosis. The amount needed depends on a careful mapping of your 'hyperhidrosis hotspots' and the severity of your problem. I usually inject between 50 and 150 units per hand. Best, Dr. Karamanoukian Los Angeles

Using botox for palmar hyperhidrosis is an effective way to decrease sweating. The botox prevents the nerves from telling the sweat glands to secrete sweat. Each palm will need 50 to 100 units depending on the size. The cost depends on the cost per unit in each office. Botox ranges from 10-15 dollars per unit in my area.