Maca root has shown modest but real effects on male sperm production and may support female hormonal balance, though the evidence is stronger on the male side. Most clinical trials have used doses between 1.5 and 3 grams per day over 8 to 16 weeks, with improvements in sperm count, sperm motility, and sexual desire being the most consistently reported benefits.
That said, the research is still limited. Many studies are small, and results vary depending on the type of maca, the dose, and the population studied. Here’s what the current evidence actually shows.
Effects on Sperm Count and Quality
The most direct fertility evidence for maca comes from studies on men. In one early trial, nine healthy men taking 1.5 to 3 grams of gelatinized maca daily for four months showed increases in seminal volume, total sperm count, motile sperm count, and sperm motility. Importantly, there was no difference between the two doses, suggesting that more isn’t necessarily better.
A larger pilot trial of 65 men with low sperm count or poor sperm motility found that 2 grams per day for 12 weeks increased sperm concentration. However, that study didn’t find significant changes in seminal volume, motility, or sperm shape. And a well-designed randomized controlled trial of 50 infertile men taking gelatinized yellow maca for 16 weeks found no significant differences in sperm parameters at all compared to placebo.
So the picture is genuinely mixed. Some men in some trials see improvements, particularly in sperm count. But the results haven’t been consistent enough across studies to call maca a reliable treatment for male infertility. The positive findings are real, but they come mostly from smaller or less rigorous trials.
Black Maca vs. Other Colors
Maca comes in several color varieties, and they don’t all do the same thing. In animal studies comparing yellow, red, and black maca, black maca was the only type that increased daily sperm production and improved sperm motility in the epididymis (the structure where sperm mature). Yellow and red maca had no significant effect on sperm count.
Red maca showed a different benefit: it reduced prostate weight in rats, which black and yellow maca did not. This suggests red maca may be more relevant for prostate health than for sperm production specifically. If your goal is to support sperm quality, black maca has the strongest animal evidence behind it, though human trials comparing colors head-to-head are still lacking.
How Maca Affects Hormones
One of the more surprising findings across maca research is that it generally does not change levels of testosterone, estrogen, FSH, or LH in men. Multiple studies have confirmed this. Whatever maca does for sperm production, it appears to work through a different pathway than simply boosting sex hormones.
In women, the story is more nuanced. A double-blind trial in early postmenopausal women found that after eight months of maca supplementation, FSH levels dropped significantly while LH increased. This shift stimulated the ovaries to produce more estrogen and progesterone, and the women reported substantially reduced menopausal discomfort. The catch: this study was in postmenopausal women, not women trying to conceive. There’s very little clinical data on maca’s hormonal effects in reproductive-age women specifically.
Animal research suggests maca’s active compounds, likely its alkaloids, act on the signaling pathway between the brain and the reproductive organs. In rats with removed ovaries, maca lowered cortisol and the stress hormone ACTH, which could indirectly support reproductive function by reducing the hormonal impact of chronic stress. But translating rat data to human fertility decisions requires caution.
Sexual Desire and Libido
Fertility isn’t just about biology. You have to want to have sex, and maca has some of its most consistent evidence in this area. A 12-week randomized trial in healthy men found that sexual desire improved by 8 weeks of maca use at both 1.5 and 3 grams per day, with no change in testosterone or estrogen levels. The effect appeared to be dose-independent.
Maca has also been studied in people experiencing sexual dysfunction from antidepressant medications. In a pilot trial, participants taking maca over 12 weeks showed significant improvement in libido scores. This is notable because antidepressant-related sexual dysfunction is notoriously difficult to treat, and most interventions either don’t work well or come with their own side effects.
Typical Doses Used in Research
Clinical trials have tested a wide range of doses, from as little as 350 milligrams to 3 grams per day. The most commonly studied and effective range for fertility-related outcomes is 1.5 to 3 grams daily of gelatinized maca powder. “Gelatinized” means the root has been cooked and processed to remove starch, which makes it easier to digest and may concentrate the active compounds.
Most trials run for at least 8 to 12 weeks before measuring outcomes, so this isn’t something that works overnight. The trial showing improvements in sexual desire saw separation from placebo at 8 weeks. Sperm studies have run 12 to 16 weeks. If you’re trying maca for fertility, give it at least two to three months before expecting to see any change.
Safety and Thyroid Concerns
Maca is a cruciferous vegetable, in the same family as broccoli and cabbage. Like its relatives, it contains goitrogens, compounds that can interfere with thyroid hormone production. For most people eating a normal diet with adequate iodine, this isn’t a practical concern. Cooking or gelatinizing maca deactivates goitrogens through heat and moisture, which is one more reason gelatinized forms are generally preferred over raw maca powder.
If you have an existing thyroid condition, particularly hypothyroidism or Hashimoto’s disease, it’s worth being aware of this. The amount of goitrogens in typical supplement doses is small, but thyroid function directly affects fertility, so it’s a factor worth considering.
What the Evidence Adds Up To
Maca sits in a frustrating middle ground. There are real signals of benefit, particularly for sperm count in men and for libido in both sexes. But the strongest positive results come from smaller studies, and larger, more rigorous trials have sometimes failed to replicate them. A 50-person randomized controlled trial in infertile men found no benefit at all.
For women trying to conceive, the evidence is thinner still. The hormonal data comes primarily from postmenopausal women and animal models, not from fertility patients. There are no published clinical trials measuring pregnancy rates in women taking maca.
Maca is generally well-tolerated and unlikely to cause harm at standard doses. As a low-risk supplement with some biological plausibility and a handful of encouraging trial results, it’s reasonable to try alongside other evidence-based fertility strategies. Just keep expectations realistic: this is a food-derived supplement with preliminary evidence, not a proven fertility treatment.