Effects of different Maca ecotypes administered for 7 days on serum testosterone (A) or estradiol (B) levels in rats. Data are mean ± SEM. Maca (2 gr/Kg BW) was administered for 7 days. Number of rats was 10 in the control group, 6 in the Red Maca treated group, 6 in the Yellow Maca, and 6 in the Black Maca treated group. P:NS between groups treated with Maca and control rats. aP < 0.05 with respect to the Yellow Maca treated group.