I might recommend ZMA for low testosterone. I was suffering from some "low drive" and started supplementing with ZMA. Along with spawning some crazy ass dreams during sleep, it put the fight back in me....errr so to say. It's also supposed to be great for those on primal/paleo that are weightlifting or active in sports.
Check it out: Now Foods, Sports, ZMA, Sports Recovery, 180 Capsules - iHerb.com