In Peru, where it is grown, maca is consumed as a food. Once placed on the endangered plant list, it is now grown on thousands of acres as a commercial product. The maca root is dried and ground, then used to make everything from soups to alcoholic beverages. The leaves are brewed for tea. Maca has been used by Peruvian consumers for many centuries, since before the time of the Incas. The Incas found maca so potent that they restricted its use to their royalty's court. Upon overrunning the Inca people, conquering Spaniards became aware of this plant's value and collected tribute in maca roots for export to Spain. Maca was used as an energy enhancer, increasing male potency or improving other hormonal function.

Aguila Calderon, M.D., the former dean of the Faculty of Human Medicine at the National University of Federico Villarreal in Lima uses maca for male impotence, erectile dysfunction, menopausal symptoms and general fatigue, and claims good results. Arizona physician Gary F. Gordon, M.D., former president of the American College for Advancement in Medicine, is also a maca supporter. He calls it "nature's Viagra".

The supposed mechanism of action is by normalizing steroid hormones such as testosterone, progesterone and estrogen. It acts on men to restore them to a healthy functional status in which they experience a more active libido. Maca may boost desire but does not share Viagra's erection-enhancing properties.

Scientist Gustavo Gonzales of Peru's Cayetano Heredia University, who led what the scientists say is the world's first study into maca's effect on humans, told a news conference the three-month trial involving 12 volunteer men pointed to an 180-200% lift in libido and up to a doubling of sperm production. Maca produced an increase in sex drive within two weeks. The study, funded by Peruvian pharmaceuticals company Hersil, also found maca reduced blood pressure and had no adverse effect on the heart. Although it also appeared to boost the production and movement of sperm, Gonzales said more research was needed as the test had been restricted to a very small sample.

To be consistent with Peruvian usage levels one should take 3,000-5,000mg per day of maca, but one can certainly take more. The more maca or maca extract that is consumed, the more the likely benefit. Toxicity studies conducted on maca in the U.S. showed absolutely no toxicity or adverse pharmacologic effects. In animal studies, the more maca animals consume, the stronger and more sexually active they become.

There are always a few individuals who will show an allergic reaction or who fall into a group of women or men for whom a pituitary stimulator such as maca is contraindicated in the absence of studies that prove its safety. Men using maca on a regular basis should undergo periodic PSA tests.