None of the anti-perspirant deodorants seem to work on me?

My Little brother is 22 and would have pit stains if he were in shorts and a t-shirt standing in the snow. He's tried doctor prescribed anti-perspirant deodorants and none have worked. Now he just uses the ones with the strongest smell. There's no hope for him, but there may be hope for you. See a doctor if you haven't already.