A Brazilian native is the muira puama tree, which gives up its stems and roots to serve as an herbal remedy for erectile dysfunction. Muira puama appears to increase blood flow to the pelvic area, which may be the reason why the herb proved beneficial for men with low libido in several French studies.
In one such study, 62 percent of the participants said muira puama “had a dynamic effect,” and more than half who had erectile dysfunction said the herb was helpful. (Waynberg 1990) Fifty-two of 94 men in another study reported that muira puama improved their erectile dysfunction. (Waynberg 1995) A typical dose is 0.5 to 1.5 grams daily, although you should consult a knowledgeable healthcare practitioner before taking this remedy.
References
Waynberg J. Male sexual asthenia—interest in a traditional plant-derived medication. Ethnopharmacology 1995
Waynberg J. Contributions to the clinical validation of the traditional use of Ptychopetalum guyanna. Presented at the First International Congress on Ethnopharmacology, June 5-9, 1990.