I ordered antihyrdal a little over a week ago and have been using it for about 10 days, applying it every night before I go to bed. I have moderate to severe hand sweating, so I was not expecting this product to be a silver bullet. Over the past 10 days I have definitely noticed a decrease in sweating, particularly in the middle of the hand; the fingertips still get damp. It is winter right now in Chicago (and rather cold right now), so obviously my hands will sweat less than during the summer. In other words, I don't know how effective this will be in the hot and humid days of a Chicago summer.

I do highly recommend combining treatments, such as using iontophoresis and using a topical before bed time (antihydral, drysol, etc...). I have not yet tried this, however.

Here is a link to a study of the effectiveness of Topical Methenamine, one of the active ingredients in Antihydral.

I do imagine that Antihydral would be extremely effective for people with mild to moderate palmar hyperhidrosis.