Maca does not raise testosterone levels. Multiple clinical trials measuring serum testosterone in men taking maca for 8 to 12 weeks have found no significant changes in either total or free testosterone compared to placebo. But the story is more interesting than that simple answer suggests, because maca does appear to improve several things people associate with testosterone, like libido, sexual function, and sperm quality, through pathways that have nothing to do with the hormone itself.
What the Clinical Data Actually Shows
The most direct evidence comes from a randomized, double-blind trial published in the World Journal of Men’s Health. Researchers gave maca or a placebo to 80 men with symptoms of low testosterone for 12 weeks. At the end of the study, men in the maca group went from an average total testosterone of 4.40 ng/mL to 4.41 ng/mL. Free testosterone barely moved either, going from 7.54 to 7.59 pg/mL. Neither change was statistically significant, and there was no meaningful difference between the maca and placebo groups.
This wasn’t a fluke finding. Across multiple human studies using doses of 1.5 g/day and 3.0 g/day, researchers have consistently found no changes in testosterone, estradiol, luteinizing hormone, follicle-stimulating hormone, or prolactin. If you’re taking maca specifically to move the needle on a blood test, it won’t.
Why People Think It Works
The confusion is understandable. Maca genuinely improves sexual desire and function in several trials, and most people assume that means testosterone went up. It didn’t. In one dose-finding study of people experiencing sexual dysfunction from antidepressants, maca significantly improved overall sexual function scores, dropping them from 23.9 (indicating significant dysfunction) to 17.3 after treatment. Libido specifically improved as well. All of this happened with zero measurable change in sex hormones.
This disconnect, better sexual function without hormonal shifts, points to a different mechanism entirely. Maca contains unique compounds called macamides, which are formed when specific fatty acids combine with benzylamine during the plant’s growth. These compounds appear to influence sexual function through pathways in the nervous system rather than the endocrine system. The practical result is that you may feel a difference in desire and arousal without your hormone panel changing at all.
Maca’s Real Benefits for Male Fertility
Where maca shows more compelling results is sperm quality. In a double-blind, placebo-controlled pilot study of healthy men, 12 weeks of maca supplementation produced upward trends across every semen parameter measured: total sperm count increased by 20%, sperm concentration by 14%, motile sperm count by 14%, progressively motile sperm count by 18%, semen volume by 9%, and normal sperm shape by 21%. An earlier study of nine men found even more dramatic results after 16 weeks, with sperm concentration rising 35%, total count jumping 84%, and motile sperm more than doubling. A third study in men with diagnosed infertility found a statistically significant 10% increase in motile sperm and 12% improvement in normal morphology.
Again, these improvements occurred without measurable changes in hormone levels. If you’re trying to optimize fertility, maca has a more credible evidence base than it does for testosterone itself.
Black, Red, and Yellow Maca Are Not the Same
Maca comes in several colors, and they have genuinely different effects. This isn’t marketing. The varieties contain different concentrations of active compounds and have been tested separately in research.
- Black maca is the strongest option for sperm production and physical endurance. Animal studies consistently show it outperforms other colors for spermatogenesis, and it also has some evidence for memory support.
- Red maca is better for prostate health, reducing prostate size in animal models of benign prostatic hyperplasia. It also showed slightly better results for mood and energy in a human study comparing it to black maca and placebo.
- Yellow maca has moderate benefits for sperm production but may actually be counterproductive for prostate health. Some clinical observations have linked it to worsening prostate-related symptoms like reduced urination.
If you’re a man choosing maca for sexual health broadly, black maca has the strongest case. If prostate concerns are part of the picture, red maca is the better choice, and yellow maca is worth avoiding.
Stress Reduction May Be Part of the Picture
Animal research suggests maca significantly lowers cortisol, the body’s primary stress hormone. In both short-term (28-day) and long-term (90-day) trials in rats, maca produced statistically significant cortisol reductions, with the stronger effect appearing in the shorter trial. The researchers also observed a simultaneous drop in ACTH, the brain signal that tells your adrenal glands to produce cortisol, suggesting maca acts higher up in the stress response chain.
This matters because chronically elevated cortisol suppresses testosterone production and wrecks libido on its own. While we can’t directly extrapolate animal cortisol data to humans, it offers a plausible explanation for why people report feeling better on maca even when their testosterone doesn’t budge. Lowering stress hormones can improve sexual function, energy, and mood through entirely separate pathways.
Dosing and Timeline
Clinical trials have used doses ranging from 1.5 g to 3.0 g per day, with most positive results appearing in the 3.0 g range. In the antidepressant study, the higher dose produced statistically significant improvements in sexual function scores, while the lower dose improved but just missed the threshold for significance. Both doses improved libido to a similar degree by 8 weeks.
Most studies run 8 to 12 weeks before measuring outcomes, and some of the more impressive sperm data came from 16-week trials. Expect to take maca consistently for at least two months before drawing conclusions about whether it’s helping. The fertility benefits in particular align with the roughly 74-day cycle of sperm development, so patience matters.
Safety Considerations
Maca is generally well tolerated in the doses used in research. The main caution applies to people with hormone-sensitive cancers, such as breast or uterine cancer, where maca could potentially interact with treatment. Memorial Sloan Kettering Cancer Center also flags pregnancy and breastfeeding as situations where safety hasn’t been established. For most healthy adults, side effects in clinical trials have been minimal and comparable to placebo.