Have any supplements been studied for male sexual dysfunction?

A handful of studies have found maca to improve sexual desire in people with and without sexual dysfunction. Additionally, cocoa extract may improve sexual function by supporting vascular health.

A number of other supplements have shown some promise (e.g., fenugreek, yohimbine, tribulus-terrestris, Eurycoma Longifolia Jack), but very little research has been conducted on any of these supplements.