[Rx-Ultram]

No one seems to know for sure and the evidence for oral cancers seems to lack any explanation of mechanism - aside from hot water (there's a blurb on wikipedia about it: http://en.wikipedia.org/wiki/Yerba_mate). I didn't like yerba mate, but I'm not a big tea fan. I'd guess that if it's just the antioxidant or caffeine you're after something like ginseng tea would give you more sustainable energy - I used this in P2.