Maca root shows promising but limited evidence for improving fertility, mostly on the male side. A small number of clinical trials suggest it can improve sperm quality and sexual function in men, while evidence for female fertility in humans is essentially nonexistent. Here’s what the research actually supports and where the gaps are.
Stronger Evidence for Male Fertility
The best-studied use of maca for fertility involves sperm quality in men. A systematic review of clinical trials found that maca may increase sperm count and motility (the ability of sperm to swim effectively). One randomized controlled trial specifically showed improvements in sperm motility in men who were already diagnosed as infertile. Two other trials found positive effects on multiple semen quality parameters in healthy men. These are small studies, but the consistency of the direction is notable.
The improvements appear to happen without directly changing testosterone levels. Studies measuring men’s blood hormone levels after maca supplementation have found no significant changes in testosterone, estrogen, follicle-stimulating hormone (FSH), or luteinizing hormone (LH). This is unusual, because most compounds that improve sperm quality do so by shifting hormone levels. Researchers believe maca may work through a different pathway, possibly acting directly on testicular tissue or through its antioxidant content, though the exact mechanism isn’t fully understood.
Very Limited Evidence for Female Fertility
Despite widespread marketing of maca as a female fertility supplement, there are no published human studies on maca and female fertility. That’s a significant gap. The claims you’ll see online are largely extrapolated from animal research or from studies on menopausal symptoms, which is a different physiological situation entirely.
What does exist is an intriguing animal study. In female rats, maca powder produced a 4.5-fold increase in LH and a 19-fold increase in FSH during the specific hormonal window that triggers ovulation. This effect was dose-dependent, meaning higher doses produced larger increases, and it was remarkably targeted. Maca didn’t change levels of other pituitary hormones like growth hormone, prolactin, or thyroid-stimulating hormone. It selectively amplified the hormonal surge that initiates ovulation.
That’s a compelling finding in theory, because LH surges are what trigger egg release in humans too. But rat physiology doesn’t always translate to people. Studies in menopausal women looking at hormone levels have found little or no changes in blood FSH and estrogen, which suggests the dramatic hormonal shifts seen in rats may not occur the same way in humans. Until human fertility trials are conducted in women, there’s no reliable evidence that maca improves ovulation, cycle regularity, or conception rates.
Sexual Function and Libido
One way maca may indirectly support fertility is through its effects on sexual desire and function. A double-blind, placebo-controlled trial gave participants roughly 5 grams of maca daily (split across three doses) for 12 weeks. Men in the maca group showed statistically significant improvements in sexual function scores compared to placebo, including measures of erectile function and overall sexual satisfaction. Symptoms associated with low testosterone, such as reduced libido and fatigue, also improved significantly.
For couples trying to conceive, low libido or sexual dysfunction can be a practical barrier. If maca helps with desire and arousal, that alone could increase the frequency of well-timed intercourse, which is one of the simplest ways to improve chances of conception.
How Long Before You’d Notice Effects
Most clinical trials showing benefits have used maca for at least 12 weeks, with daily doses in the range of 1.5 to 5 grams. The sperm quality studies generally assessed outcomes after several weeks to a few months of consistent use. Since sperm take about 74 days to fully develop, any supplement targeting sperm quality needs at least two to three months to show results. There’s no evidence that short-term or occasional use produces meaningful changes in fertility markers.
Safety Considerations
Maca is generally well tolerated in the doses used in clinical trials. It has a long history of use as a food crop in the Peruvian Andes, where it’s consumed in much larger quantities than what’s found in supplements.
However, there are a few things worth knowing. Maca contains compounds called glucosinolates, which are found in all cruciferous vegetables and can potentially interfere with thyroid function in people who are already iodine-deficient. If you have a thyroid condition, this is worth discussing with your provider.
More importantly, Memorial Sloan Kettering Cancer Center flags maca as a concern for anyone with hormone-sensitive cancers, including breast or uterine cancer, because it may interact with hormone-related treatments. The research on whether maca actually shifts hormone levels in women is mixed: some studies show modest hormonal effects, others show none. That inconsistency is itself a reason for caution if you have a condition where hormone fluctuations matter, such as endometriosis or estrogen-receptor-positive cancer.
The Bottom Line on Maca and Fertility
For men, there’s a reasonable basis to try maca as a complement to other fertility efforts. The evidence for improved sperm quality is consistent across several small trials, and the safety profile is favorable. A dose of 1.5 to 3 grams daily for at least three months aligns with what the research has tested.
For women, the honest answer is that we don’t know yet. The animal data is intriguing, and the libido benefits could help indirectly, but no human study has demonstrated that maca improves ovulation, hormonal balance, or pregnancy rates in women. If you’re relying on maca as a primary strategy for female fertility, you’re operating well beyond what the current evidence supports.