Maca is a cruciferous vegetable that belongs to the broccoli family. It has been shown to have powerful libido-enhancing properties (18, 19), but let’s see if it has any interaction with testosterone:

• ​57 men were given a daily dose of either 1.5g or 3g of maca over 12 weeks. Although subjects in both groups experienced increases in sexuality, no change in testosterone levels was observed (20).
• Another study, with basically the same context as the one above (56 men, 1.5g or 3g of Maca, 12 week time frame), also observed the same result: no interaction with testosterone (21).

It’s important to understand that although higher testosterone is associated with an increased sex drive, the inverse is not necessarily true (higher libido does not mean higher testosterone).

Maca is an ingredient that leads the user to believe that it must be working, due to their increased libido. But the bottom line is that it influences parameters of libido without having any interaction with testosterone.

(source)​