I have used maca on and off for a while. I definitely notice an increase in libido while using it, but only when I was using a high dose. About 6-8 grams/day is enough to do it for me. My libido is pretty high anyway, but this stuff was taking me to new levels of horny lol. And there's also the nice side effect of being able to plaster a whole wall while you are using it. Takes a few days to kick in.