I've tried Fenugreek, the Testofen sort and for the opposite aims. I recall it being good for lifting weights (coupled with L Arginine). The Testofen form was noted for increasing T and making one smell like maple syrup!

Some users claimed it could make them unduly belligerent...which I don't doubt. I'm sure many took it as a sign something was working.
The full spectrum stuff is probably a whole different animal, but it's good to know that if you concentrate the heck out of one it's key components, it's been shown to increase testosterone.