Maca (Lepidium meyenii, Brassicaceae) tubers have been used by indigenous Peruvians as a medicinal food since antiquity. Age- and gender-specific physiological effects of maca have been seen in vivo and in human trials with male and pre- and postmenopausal female subjects. Effects vary by color phenotype and levels of bioactive compounds, including glucosinolates (GCs). In an earlier study, red maca (RM) was found to have the most GCs. RM is reported to have a selective therapeutic effect in men over 50 against prostate hyperplasia. Black maca (BM) and purple maca (PM) had the next-highest GC levels in the earlier study. BM was reported to improve sexual desire and function in healthy men. Yellow maca (YM), with the least GCs, in a mixed-phenotype, traditional blend, was reported to help hormone balance in pre- and postmenopausal women. The effect of altitude on plant composition has been well documented across various…