There are a number of natural supplements that “may” impart the androgenic effects that you desire (increased sex drive, increased vasodilation in the penis) such as horny goat weed, yohimbe(sp), tribulus terrestis(sp) and many more. Most of the studies using these ingredients however have been conducted using out of shape or old men, ie those with already suboptimal testosterone levels, so if you are healthy, young, and in shape they will probably not help you.
I’ll ask the obvious next, why not Viagra or cialis? I have personally tried cialis and all I got was a headache and no noticable effect on EQ. Personally, I’ve had the best sex of my life, hardest erections, and highest sex drive of my life while on melanotan II and testosterone (obviously injectables, not orals — research responsibly and use at your own risk). Cheers.