There is some evidence that maca may improve sexual function in men, but it is not clear if this is because of its effects on testosterone levels or some other mechanism. Preliminary studies suggest that maca may work like Viagra by increasing blood flow to the penis. However, more research is needed to confirm this. If you are considering using maca to improve your sexual function, talk to your doctor first to make sure it is safe for you. Maca may also interact with certain medications, so be sure to let your doctor know if you are taking any supplements or medications. There is no evidence that maca has any effect on female sexual function. In fact, one study showed that maca actually decreased libido in women. So if you are a woman interested in using maca to improve your sexual function, you should probably avoid it. Again, talk to your doctor before starting any supplement, including maca. Maca may interact with certain medications as well, so be sure to let your doctor know if you are taking any supplements or medications.