A couple of natural supplements that i have been testing:
Black ginger extract.(500mg) - this works but i think there is a plateu effect
L-ARGANINE - Supposed to boost NO2. You would need to dose at 2g-3g/day.
Tongkat ali is supposed to help boost test. I havnt tried
Tribulus is another one i havnt tried yet
Fedosia argrestus is another one i havnt tried yet.
Again these are all natural supps. But yea not medical advice lol