First off...how can someone with 13 posts come on here and start flaming and it's fine and dandy with the mods? I wonder if these flames were directed elsewhere how long they would last.
Anyway... each herb works through a different pathway. Avena Sativa lowers SHBG, which binds T. So Avena doesn't really raise test levels but does make ones natural testosterone more "available" by increasing the "free" testosterone already in the body. Although there isn't as many research studies on it, Muara Puama seems to do the same thing and has ad a "folklore" repution as an aphrodesiac.
Xanthoparmilia increases nitric oxide which is exactly what viagra does, so this is a basic chemical reaction. It works!
Maca is a mystery. It doesn't necessarily increase T but it is a genuine sex stimulent. It isn't placebo either. Tests on rats were done that showed copulation DOUBLED in rats that were given Maca. Most everyone who has tried it agrees it does "something."