Another study published in the journal Reproductive Biology and Endocrinology in 2005 found that male rats given maca extract had higher sperm counts and increased sperm motility. Proponents of maca claim that it can boost testosterone levels, improve athletic performance, and even enhance fertility. If you’ve ever been to a health store, you’ve likely seen maca marketed as a supplement to boost energy and libido. While direct increases in testosterone might not be evident with Maca consumption, it’s possible that the root has some indirect benefits. In fact, many studies indicate that Maca does not alter serum testosterone levels. But what about its potential effects on testosterone levels? Preliminary human research and traditional use data suggest yes — maca may support erectile function through improved libido, nitric oxide-related circulation benefits, and reduced performance anxiety. Research suggests ashwagandha may be more effective than maca for directly increasing testosterone levels. Ashwagandha has more direct evidence for increasing testosterone levels in some studies. When combined with other herbs like Tribulus terrestres, maca might influence testosterone levels indirectly. However, research shows it doesn't directly increase testosterone levels in most men. Many people have questions about maca's effects on testosterone and overall hormonal health. Since maca appears to influence hormone levels, it could potentially complicate certain health conditions. Rather than altering hormone levels, maca appears to work through other pathways to improve sexual drive. Maca root, scientifically known as Lepidium meyenii, is a root vegetable that grows natively in the high Andes of Peru and Bolivia. For example, given that specific herbs have anti-inflammatory and antioxidant activity, these may provide the greatest benefits for men presenting with excess premorbid inflammation or oxidative stress. Finally, matching treatment based on presentation may also clarify populations in whom herbal supplementation may be most beneficial. Examining the safety and efficacy of an herb in different populations, such as healthy, aging men; men with comorbid medical conditions such as metabolic syndrome, obesity, or diabetes; men engaging in regular exercise; and in men taking concurrent medications, will also help to determine the most suitable groups to target for its use. Moreover, there was significant variability in the herbal extracts used, which may impact safety and potency. The dosages used in the included studies varied widely, making an evaluation of safety and efficacy difficult. In addition, given the existing controversy regarding the relative importance of "bound" and "unbound" testosterone (34), data for testosterone fractions and binding proteins were extracted and presented in the current review to increase the scope of findings. A strength of this systematic review is the inclusion of only randomized controlled trials investigating the effect of a single herb on testosterone concentrations in men. For example, reasons for 2 of the 6 fenugreek seed extract studies and 1 of the 4 ashwagandha root/leaf studies not achieving significant differences between groups were not discussed. If future, robustly-designed studies demonstrate consistent positive effects of some of these herbs on testosterone production, further research will also be required to elucidate their potential mechanisms of action. Moreover, in animal studies, the administration of 4-hydroxyisoleucine, an extract from fenugreek seeds, lowered serum cortisol concentrations (77). It has been shown to improve libido and sexual function independent of hormone changes. However, scientists need to study maca more extensively before recommending it for treating any health condition or symptom. However, various research studies have found noticeable positive effects after 12 weeks of maca use. However, a 2018 study examined a case of a woman whose blood lead concentration increased after she consumed a maca supplement. Limited evidence from animal research suggests that maca may have benefits for BPH, brain health, and skin health. Human research investigating the potential health benefits of maca is limited.