Maca shows some promising signs for improving sperm quality in men, but the evidence is still limited, and no study has demonstrated that it actually increases pregnancy rates. Most of the research involves small trials, and a recent systematic review found that the variation in doses, durations, and study designs made a proper meta-analysis impossible. So while maca isn’t without merit, calling it a proven fertility treatment would be a stretch.
What the Evidence Shows for Men
The strongest fertility data for maca comes from male sperm parameters. In a double-blind, placebo-controlled pilot study, healthy men who took maca for 12 weeks saw upward trends across the board: total sperm count increased by about 20%, sperm concentration by 14%, motile sperm count by 14%, and normal sperm shape improved by 21%. Semen volume went up roughly 9%. Those are meaningful numbers on paper, but this was a small pilot study, not a large-scale trial confirming real-world results.
An earlier study found similar directional improvements after four months of supplementation at doses of 1.5 to 3.0 grams per day, though it included only nine men and no placebo group. The pattern across studies is consistent: sperm parameters tend to improve, but the trials are small and haven’t tracked whether those improvements translate into more pregnancies.
What the Evidence Shows for Women
Research on maca and female fertility is far thinner and mostly confined to animal studies. In ovariectomized rats (animals with their ovaries removed to simulate menopause), a processed form of maca influenced levels of estrogen, progesterone, follicle-stimulating hormone, and luteinizing hormone along the hormonal pathway connecting the brain to the ovaries. In rats with functioning ovaries, maca lowered estrogen while raising progesterone. The researchers suggested this hormonal balancing effect could be relevant for premenopausal women, but no human clinical trial has confirmed this.
For women trying to conceive, there’s simply no published trial measuring whether maca improves ovulation, cycle regularity, or pregnancy outcomes in humans. The theoretical basis exists from animal work, but it hasn’t been tested where it counts.
Maca Doesn’t Appear to Change Hormone Levels
One of the more surprising findings is that maca does not seem to alter reproductive hormone levels in humans. A study tracking men over 12 weeks measured luteinizing hormone, follicle-stimulating hormone, prolactin, testosterone, and estradiol at multiple time points. Compared to placebo, maca had no effect on any of these hormones, and the results held true at both 1.5 and 3.0 grams per day. Multiple regression analysis confirmed testosterone was unaffected at every time point.
This creates an interesting puzzle. If maca improves sperm quality but doesn’t change testosterone or other reproductive hormones, it may work through a different pathway entirely. Maca contains plant sterols that are structurally similar to estrogen, testosterone, and progesterone, and it also contains unique fatty acid compounds that interact with the body’s endocannabinoid system. But scientists haven’t pinned down which compounds are responsible for the reproductive effects, or exactly how they work. A 2024 review concluded that further research is essential to uncover these mechanisms.
Libido vs. Actual Fertility
Much of maca’s reputation comes from its traditional use as an aphrodisiac in the Peruvian Andes, and the libido data is actually more robust than the fertility data. Men taking maca reported improved sexual desire as early as eight weeks, independent of any hormone changes. A separate dose-finding study in people with antidepressant-related sexual dysfunction found significant improvements in sexual function at both 1.5 and 3.0 grams per day, with the higher dose appearing more effective.
This distinction matters. If you’re searching for fertility help, you should know that maca’s best-supported benefit is increasing desire and sexual function, not improving your chances of conception. Those two things are related, of course, since more frequent sex improves odds. But they’re not the same as a direct effect on egg quality, ovulation, or fertilization.
Dosage and How Long to Take It
Clinical trials have consistently used doses between 1.5 and 3.0 grams per day of maca root powder or its equivalent. One study used 1.75 grams daily. Results in sperm parameters typically appeared after 12 weeks of consistent use, and some researchers extended supplementation to four months. Improvements in sexual desire showed up a bit sooner, around 8 weeks.
If you’re considering maca, plan for at least three months before expecting to see any effect on reproductive markers. Shorter durations haven’t been well studied for fertility outcomes.
Different Colors May Matter
Maca roots come in several color varieties, primarily yellow, red, and black. A 2024 review noted that not all maca is equivalent in its chemical profile. Black maca has been more closely associated with sperm production in animal studies, while red maca has been studied for prostate health. Yellow maca is the most common commercial variety. Most human fertility trials haven’t specified or compared colors, which adds another layer of uncertainty to the evidence. If a supplement doesn’t specify the variety, it’s likely yellow or a blend.
Safety Considerations
Maca has been consumed as a food in Peru for thousands of years and is generally well tolerated in the doses used in clinical trials. It contains plant sterols that are structurally related to steroid hormones, which raises a theoretical concern for people with hormone-sensitive conditions like certain breast, uterine, or prostate cancers, endometriosis, or uterine fibroids. No adverse effects in these populations have been documented in trials, largely because these groups haven’t been studied. If you have a hormone-sensitive condition, it’s worth discussing maca with your provider before starting it.
Maca also contains compounds called glucosinolates, which are found in cruciferous vegetables like broccoli and cabbage. In very high amounts, glucosinolates can interfere with thyroid function, particularly in people with iodine deficiency. At typical supplement doses, this is unlikely to be an issue, but it’s worth noting if you have an existing thyroid condition.