Red Maca Root and Sexual Function

Red maca root has been studied most often for its effects on sexual desire and erectile function in men. A 2009 randomized controlled trial published in BMC Complementary and Alternative Medicine found that men taking 1.5 to 3 grams of red maca daily for 12 weeks reported improvements in sexual desire compared to those taking placebo. The effect was modest but measurable, and appeared after about 8 weeks of consistent use.

The mechanism is not fully understood. Red maca contains compounds called glucosinolates and alkaloids that may influence blood flow or hormone signaling, but human studies have not yet pinpointed which compounds do the work or how. Most research has been conducted in Peru, where maca is grown, and sample sizes have been small—usually 50 to 100 participants. Larger, independent trials would strengthen the evidence.

For women, the data is thinner. One small 2008 study found that women taking maca reported increased sexual desire after 8 weeks, but the effect size was small and the study lacked a placebo control group, which weakens confidence in the result.

Key Takeaways

  • Red maca has been shown in small human trials to increase sexual desire in men after 8 to 12 weeks at doses of 1.5 to 3 grams daily, though the effect is modest and the mechanism remains unclear.
  • The active compounds in red maca—glucosinolates and alkaloids—may influence blood flow or hormone signaling, but this has not been confirmed in human studies.
  • Evidence for red maca's effects on women's sexual function is limited to one small study without a placebo control, so claims about female benefit are not yet well-supported.
  • Red maca does not appear to raise testosterone levels in men, despite marketing claims suggesting it does.
  • Most published research on maca comes from Peru and involves small sample sizes, so results should be interpreted cautiously until larger independent trials are completed.

Hormone Levels and Testosterone

Marketing for red maca often claims it boosts testosterone, but human studies do not support this. A 2016 meta-analysis of randomized controlled trials found no significant change in testosterone levels in men taking maca compared to placebo, even at doses up to 3 grams daily for 12 weeks. This is an important distinction: maca may improve sexual function through pathways unrelated to testosterone production.

Animal studies have shown that maca compounds can affect hormone-related tissues in rats and mice, but these effects do not automatically translate to humans. The doses used in animal work are often much higher than what people consume, and animal physiology differs from human physiology in ways that matter for hormone regulation.

Mood, Energy, and General Wellness

Some people report feeling more energetic or having a better mood after taking red maca, and a few small studies have examined this. A 2008 trial found that men taking maca for 12 weeks reported modest improvements in mood and reduced anxiety compared to placebo, but the study involved only 57 participants and did not measure mood using a validated clinical scale.

The evidence for maca as a general energy or mood supplement remains preliminary. No large, well-designed trials have tested whether red maca prevents fatigue or depression in people without a specific condition. Anecdotal reports of improved energy are common, but anecdotes do not distinguish between the effect of the compound itself and the placebo effect—the measurable benefit people experience from believing they are taking something active.

Fertility and Sperm Quality

A 2016 randomized controlled trial published in Andrologia found that men taking 2 grams of maca daily for 12 weeks showed improvements in sperm count and sperm motility (movement) compared to placebo. The study involved 60 men and used standard laboratory measures of semen quality. However, the trial did not track whether these men actually fathered children at higher rates, so the real-world significance of the improvement remains unclear.

Other small studies have reported similar findings, but most have been conducted in Peru and have not been independently replicated in other countries. The compounds in maca that might improve sperm production have not been isolated or tested separately in humans.

Side Effects and Safety in Short-Term Use

Red maca is generally well-tolerated at doses of 1.5 to 3 grams daily for periods of 12 weeks or less. The most commonly reported side effects in clinical trials are mild: digestive upset, headache, and insomnia. These occurred in fewer than 10% of participants and were not significantly more common than in the placebo groups.

Long-term safety data—studies lasting more than 12 weeks—do not exist in humans. Animal studies have not revealed toxicity at high doses, but this does not may provide safety in people over months or years. Pregnant and nursing women should avoid red maca, as no safety data exist for these populations. People taking medications that affect blood pressure or blood clotting should consult a healthcare provider before use, since maca may have mild effects on circulation.

How Red Maca Differs From Other Maca Colors

Maca root comes in several colors—red, black, yellow, and cream—and they are sometimes marketed as having different effects. Red maca is often promoted specifically for sexual function and fertility, while black maca is sometimes claimed to improve athletic performance and muscle. These distinctions are based on traditional use and marketing rather than rigorous comparative research.

Only one published study has directly compared different maca colors in humans. A 2012 trial found that red and black maca had slightly different effects on sexual desire in men, but the study was small (30 participants per group) and the differences were not large enough to be clinically meaningful. Most of the evidence base for maca's effects comes from studies that did not specify which color was used or used a mixture of colors, so claims about red maca's unique benefits should be treated as preliminary.

What the Research Cannot Yet Tell You

The existing research on red maca leaves several important questions unanswered. No studies have compared maca to prescription treatments for erectile dysfunction or low sexual desire, so it is not possible to say whether maca is more or less effective than established options. No trials have tested whether maca works better for some people than others—for instance, whether age, baseline hormone levels, or other health conditions predict who will benefit.

The active compounds in red maca have not been conclusively identified or tested in isolation in humans. This means that when you buy a red maca supplement, you cannot be certain which components are responsible for any effects you experience, and different products may contain different ratios of active ingredients depending on growing conditions and processing methods.

Frequently Asked Questions

How long does it take red maca to work?

In the clinical trials that found an effect, improvements in sexual desire typically appeared after 8 to 12 weeks of daily use at doses of 1.5 to 3 grams. Some people report noticing changes sooner, but this may reflect placebo effect rather than the compound itself. Consistent daily use appears necessary; occasional use has not been studied.

Does red maca raise testosterone?

No. A meta-analysis of randomized controlled trials found no significant increase in testosterone levels in men taking maca compared to placebo. Maca may improve sexual function through other mechanisms, but testosterone elevation is not one of them based on current evidence.

Is red maca safe to take every day?

Red maca appears safe at doses of 1.5 to 3 grams daily for up to 12 weeks based on clinical trial data. Long-term safety beyond 12 weeks has not been studied in humans. Mild side effects like digestive upset and headache occur in a small percentage of users. People on blood pressure or blood-thinning medications should check with a healthcare provider first.

Can women take red maca?

Yes, but evidence for effects in women is limited. One small study found increased sexual desire in women taking maca, but it lacked a placebo control group. Red maca has not been studied in pregnant or nursing women, so these groups should avoid it. Women with hormone-sensitive conditions should consult a healthcare provider before use.

What dose of red maca was used in the research?

Most studies used 1.5 to 3 grams of maca powder or extract daily. Some used 2 grams specifically. Trials lasted 8 to 12 weeks. Supplement labels often recommend similar doses, but there is no established "optimal" dose, and different products may vary in concentration and potency.