Maca Root for Erectile Dysfunction: What Human Studies Do (and Don’t) Show

Maca root (Lepidium meyenii) is a Peruvian plant often marketed as a natural remedy for low libido and erectile dysfunction (ED). While animal studies suggest potential benefits, human research remains limited. Below is a balanced look at what the existing trials tell us—and where more data are needed.

What Is Maca Root?

Maca is a cruciferous vegetable that grows at high altitudes in the Andes. Traditionally, it’s been used to:

• Support energy and stamina
• Enhance fertility and sexual desire
• Provide vitamins, minerals, and plant compounds

In supplement form, maca root is usually sold as a powder, capsule, or liquid extract.

Key Human Trials on Maca and Sexual Function

Gonzales et al. (2001)

Journal: Journal of Endocrinological Investigation
PubMed ID: 11738142

• Design: Randomized, double-blind, placebo-controlled
• Participants: 57 adult men with self-reported low sexual desire
• Intervention: 1,500 mg maca daily vs. placebo for 12 weeks
• Outcomes:
  • Significant increase in sexual desire score vs. placebo
  • No serious adverse effects reported
• Takeaway: Maca may boost libido, but this study did not specifically measure erectile function (for example, using an erectile function questionnaire).

Meissner et al. (2006)

Journal: International Journal of Biomedical Science
PubMed ID: 16830898

• Design: Open-label pilot study (no placebo)
• Participants: 50 men with mild ED, average age ~35
• Intervention: 2,400 mg maca daily for 12 weeks
• Outcomes:
  • Improvements in self-reported erectile function and overall sexual satisfaction
  • 24% of participants rated their erections “much better”
  • Mild side effects (stomach upset) in a small number of men
• Takeaway: Promising signals, but without a control group, it’s hard to separate placebo effects from real benefits.

What These Studies Don’t Show

• Long-term safety and effectiveness
  Both studies lasted 12 weeks—too short to know if benefits persist or if rare side effects emerge.
• Optimal dosage
  Trials used 1,500–2,400 mg daily, but the best dose (and form) remains unclear.
• Erectile function measured objectively
  Neither study used gold-standard measures such as the International Index of Erectile Function (IIEF) in a blinded, placebo-controlled setting.
• Diverse populations
  Participants were generally healthy adult men. We don’t know if older men, those with diabetes, high blood pressure, or other health issues will respond the same way.
• Comparison to approved ED treatments
  No head-to-head trials compare maca with medications like sildenafil (Viagra®).

Possible Mechanisms of Action

Although human data are limited, maca may support sexual health through:

• Hormonal balance
  Some studies note slight increases in luteinizing hormone (LH) and other regulators of sex hormones.
• Nutrient content
  Rich in amino acids, vitamins, and minerals that support energy and blood flow.
• Adaptogenic effects
  May help the body manage stress, indirectly benefiting sexual performance and desire.

Safety Profile and Side Effects

Maca is generally well tolerated. In the human trials:

• Mild gastrointestinal upset (nausea, cramps) was the most common complaint.
• No serious adverse events were reported.
• Long-term safety remains unstudied.

If you have thyroid issues, note that maca contains goitrogens—compounds that can interfere with thyroid function when consumed in very high amounts.

Practical Tips for Trying Maca Root

If you decide to try maca root for erectile dysfunction, consider the following:

• Start with a low dose: 500–1,000 mg per day, then gradually increase.
• Choose a reputable brand: Look for third-party testing for purity and potency.
• Take it consistently: Benefits in studies appeared after 6–12 weeks.
• Monitor your response: Keep a diary of any changes in sexual desire, erection quality, and side effects.
• Combine with healthy lifestyle: Regular exercise, balanced diet, stress management, and quality sleep are foundational for sexual health.

Who Might Benefit Most?

Maca root for erectile dysfunction could be worth a try if you:

• Have mild ED or low libido without an obvious medical cause
• Prefer natural supplements over prescription drugs
• Are willing to wait at least 6–12 weeks for potential effects

Limitations and When to Seek Medical Help

If you experience any of the following, see a healthcare provider promptly:

• Sudden, painful erections lasting more than 4 hours (priapism)
• Significant changes in vision or hearing
• Chest pain or shortness of breath during sexual activity
• Persistent or worsening ED despite lifestyle changes and supplements

For serious or life-threatening concerns, always speak to a doctor right away.

You might also consider doing a free, online symptom check to get personalized guidance on when to seek professional care.

Bottom Line

• Human studies suggest maca root may improve sexual desire and might help mild ED, but the evidence is far from conclusive.
• Benefits in trials were modest, with short durations and small sample sizes.
• There are no definitive, placebo-controlled studies measuring erectile function with maca.
• Side effects appear mild, but long-term safety is unknown.
• If you choose to try maca, give it at least 8–12 weeks, monitor your response, and maintain healthy lifestyle habits.

Finally, always speak to a doctor before starting any new supplement, especially if you have underlying health conditions or are taking medications. Serious symptoms—such as priapism or chest pain—require immediate medical attention.