However, you might actually be better off going one step back in the chain reaction and taking an L-citrulline supplement. While your body converts L-arginine to nitric oxide, it also metabolizes it too fast when the amino acid is taken in an oral supplement, according to a 2011 study from the University of Foggia in Italy. L-citrulline, which the body converts to L-arginine, is actually a better option to follow the same metabolic pathway and serve as a treatment for ED, the same study found.
The Science: Some studies have implied that feeding maca to domestic cattle increases sperm production, but there is very little data about any sexual effect on humans. One very small randomized double-bind trial of men with erectile dysfunction found that men taking maca extract reported a small increase in their ability to get erections. But so did the control group. As with the fenugreek study, a similar study with a larger group of people is needed to see whether any differences between the controls and the maca-eaters are real.
'After my divorce, I began dating again and met a few lovely women. But -can you believe it - every time I 'got lucky', the whole thing fell flat and I just couldn't perform! Exercise helped a bit, but I just wasn't the man I used to be. Things were going from bad to worse and I even stopped dating because I was so anxious! Eventually a friend told me about Ikawe and I thought 'What have I got to lose?' Six weeks later, I just can't get enough and nor can my new girlfriend! What a difference!' - Stewart, U.K.