Maca (Lepidium Meyenii)

We evaluated 36 human studies on Maca (Lepidium meyenii), including 15 randomised controlled trials and 8 meta-analyses or systematic reviews; the controlled studies include 802 participants in total. As of 14 October 2026.

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1. What Is Maca (Lepidium Meyenii)? Occurrence, Origin and Forms

Maca is a cruciferous plant (Brassicaceae) cultivated in the highlands of the Andes. Its main use is the thickened root, which is eaten dried as a food. Traditionally, it is regarded in its region of origin as a food and a tonic, mentioned in connection with fertility, energy and well-being during menopause.

Maca thrives at high altitude on poor soils of the Andes and is cultivated there as a crop. Outside that region it is grown as a crop only in a few places.

The root is harvested, dried and processed into powder or flour; for supplements it is additionally heated (gelatinized) or processed into extracts. Human studies mainly use dried root powder, gelatinized powder, and aqueous or alcoholic extracts.

Forms and Preparations Studied

• Dried root powder
• Gelatinized powder (heated material)
• Aqueous extract
• Alcoholic extract
• Root colour types: yellow, red, black
• Maca flour as a food

Not covered on this page:

• Other Lepidium species, such as garden cress (Lepidium sativum)
• Preparations combining maca with other ingredients (mixtures)
• Other root and tuber crops used in a similar way, such as ginseng

2. What Does Maca (Lepidium Meyenii) Do? Results by Area

How to read the table: counted are human studies whose results concern the area. “High” means at least one meta-analysis and two controlled studies showing improvement, or at least three controlled studies of which three quarters show improvement, with at least 300 participants in total. “Moderate” means at least two controlled studies showing improvement, as a majority, or one meta-analysis alongside controlled studies. “Low” means one controlled study showing improvement. Where an area has no controlled study, the strength of evidence is at most “low” (result “reviews only” or “observational data only”). Everything else is “unclear”. A study counts as showing improvement when at least half of its outcomes in this area improved. Reviews of combination products do not count as meta-analyses; results that only describe side effects or shares of users do not count as an effect. The same study is counted only once.

3. What the Studies Show in Detail

Maca (Lepidium Meyenii), Sexual Function and Libido: Human Studies

In men with symptoms of late-onset hypogonadism, gelatinized maca improved erectile function more than placebo 11. In men with mild erectile dysfunction, the IIEF-5 score increased more with a dry extract than with placebo; the effect was small 14. In women with antidepressant-induced sexual dysfunction, the remission rate was higher with maca than with placebo, especially in postmenopausal women 15. In a dose-comparison study, sexual function improved only with the higher dose, not with the lower one 19. A randomized controlled trial in postmenopausal women found an improvement in sexual dysfunction 21. Another randomized controlled trial in healthy men found increased sexual desire 23. The findings are predominantly based on dried root powder and gelatinized powder, the individual studies are small and short, and a meta-analysis on herbal agents for erectile dysfunction provides no clear result specifically for maca 1.

Further studies in this area: 28 32 33 34

Maca (Lepidium Meyenii) and Menopausal Symptoms: Human Studies

For menopausal symptoms, a systematic review and a randomized controlled trial found lower scores on Kupperman and Greene scales; the review rates the evidence as limited 816. Two randomized controlled trials found an improved Kupperman index 1020. Two randomized controlled trials reported a decrease in hot flashes and night sweats 1016, one randomized controlled trial reported an improvement in depressive mood 17 and another reported higher estradiol, FSH and progesterone levels 20. For the remaining laboratory values, one randomized controlled trial found no difference 17. Predominantly gelatinized powder was examined, as well as dried root powder of the maca root; the studies were small and short, and information on the ecotype of the root and on manufacturer funding is mostly missing.

Maca (Lepidium Meyenii), Semen Quality and Male Fertility: Human Studies

On sperm quality and male fertility, several controlled studies and two review articles are available that do not show a uniform picture. A randomized controlled trial reported a higher sperm concentration in men with mild astheno- and/or oligozoospermia taking 2 g of maca daily than with placebo 12. For sperm motility, semen volume and normal sperm morphology, the same study found no difference 12. A small randomized controlled pilot study in healthy men saw only increasing trends compared with placebo for sperm concentration and motility 18. Another randomized controlled trial with yellow maca powder found no difference in sperm concentration in infertile men 13. A systematic review reports better sperm motility in infertile men and better semen quality parameters in healthy men 7, while a meta-analysis shows no difference in sperm concentration and unclear results for semen quality parameters 5. The findings come predominantly from small, short studies in different populations; the forms used range from dried root powder to gelatinized powder to preparations not further specified, and the evidence is inconsistent regarding ecotypes, amount and duration of use.

Further studies in this area: 34 35

Maca (Lepidium Meyenii), Mood and Psychological Well-Being: Human Studies

A randomized controlled trial with aqueous extract of black or red maca found better mood in adults at low and high altitude 9. Another randomized controlled trial with maca dry extract found a greater increase in the score for mental performance in the satisfaction profile SAT-P in men with mild erectile dysfunction than with placebo 14. In contrast, a randomized controlled trial with gelatinized powder (Maca Gelatinizada) found no difference in depression and anxiety in healthy men 23. The evidence is moderate; the findings come from three controlled studies with a total of 225 participants that investigated different forms and ecotypes, and no meta-analysis is available.

Maca (Lepidium Meyenii), Fatigue and Exhaustion: Human Studies

A randomized controlled trial with 175 adults at low and high altitude found better energy with an aqueous extract of black or red maca compared with placebo 9. A case series reports more energy with gelatinized powder in one of two men with andropause and sperm dysfunction 26. A review article mentions favorable effects on energy and mood 34. The evidence is low, as only one controlled study is available and the remaining observations have no control group. An aqueous extract and gelatinized powder were investigated, but not the raw root as a food; effects with longer use and with other preparations remain open.

Maca (Lepidium Meyenii): Further Outcomes in Studies

In this area, 14 controlled studies with a total of 668 participants as well as two meta-analyses and two systematic reviews were examined. Several controlled studies found improvements in blood pressure values after dried root powder or gelatinized powder 1720. Several controlled studies also found improved blood lipid values after gelatinized powder 1020. For hormones, a mixed picture emerged: Two controlled studies found higher estradiol and lower FSH values after gelatinized powder 1016, while several controlled studies found no differences in serum hormones 18212223. One controlled study reported a decrease in free testosterone 13. The studies are heterogeneous with regard to the maca form used, the ecotype, and the number of participants, and several investigations include only small samples.

Further studies in this area: 14 16 17 18 20 21 22 23 24 25 26 27 28 31 34

4. How Is Maca (Lepidium Meyenii) Dosed? Preparation, Dose and Duration in Studies

The studies predominantly used dried root powder and gelatinized powder, as well as aqueous and alcoholic extracts. Individual investigations examined specific ecotypes such as yellow, red or black maca. The amounts administered can be found in the table.

5. Is Maca (Lepidium Meyenii) Safe? Side Effects in Studies

In the studies, maca was predominantly well tolerated; one placebo-controlled study reported no serious side effects 91519. A review reports rare side effects and good tolerability at therapeutic dose, but points to risks with overdose or self-medication 628. A case report mentions an elevated blood lead concentration 27.

6. What Remains Open: Limits of the Evidence

• Most studies are small and short; information on ecotype and manufacturer funding is often missing.
• The forms and preparations used differ greatly, which makes comparison difficult.
• Regarding semen quality, the results are inconsistent and the evidence is heterogeneous.
• Long-term effects and effects with longer use are hardly studied.
• Combination products with other ingredients do not allow any statement about maca alone.

7. Bottom Line: What Is Established About Maca (Lepidium Meyenii)

Maca is the thickened root of the Andean Brassicaceae Lepidium meyenii, which has been studied dried as a food and in various preparations. Controlled human studies show improvements in menopausal symptoms, sexual function and libido, as well as in mood and energy. The strength of evidence is moderate for menopausal symptoms, sexual function and mood, and low for fatigue. For semen quality, the picture is inconsistent. The studies are predominantly small and short, and the forms, ecotypes and amounts used vary greatly.