Maca

What it is

Maca, botanically Lepidium meyenii, belongs to the crucifers, the mustard family. The plant grows in the Andes at altitudes of up to 4,450 m. The thickened tuber, the so-called hypocotyl, is used. In Peru it is traditionally eaten heated, processed into flour after drying, or cooked into porridge and drinks.

According to the BfR, dried maca consists of about 59 percent carbohydrates, about 10 percent protein and 8.5 percent fiber. There are color variants from yellow through red and purple to black; a 2024 review describes up to 17 of them. Color, growing location and processing change the profile of constituents. In stores, maca is mostly available as powder, as gelatinized powder, in which the starch has been broken down by heating, or as an extract.

How it is supposed to work

Maca contains a range of substances that hardly occur elsewhere in this combination. These include glucosinolates at 0.5 to 2 percent in the dried tuber, as well as macamides, macaenes, alkaloids and sterols. The macamides chemically resemble the body’s own messenger anandamide. In laboratory and animal experiments they inhibit the enzyme FAAH, which breaks down anandamide. That is a plausible route to mood and drive, but it has not been measured in humans.

What is clear, by contrast, is how maca does not work. In the study by Gonzales and colleagues, LH, FSH, prolactin, testosterone and estradiol remained unchanged over 12 weeks, and the increased desire could not be explained by better mood either. In postmenopausal women, two crossover studies also found no hormonal changes, and in laboratory tests maca showed no notable estrogenic or androgenic activity. So maca is not a plant hormone and not a testosterone booster.

Red, black, yellow maca

In the scene, black maca is considered maca for men, red maca for women. This is not entirely made up. In a study with 175 participants, extracts of red and black maca improved mood and energy, red somewhat more. Black maca contained more macamides, red more GABA. However, robust comparative studies on the colors are lacking, and most older studies do not even mention the color.

What the studies show

Libido without hormonal effect

Over 12 weeks, Gonzales and colleagues compared 1.5 g and 3.0 g of maca per day with placebo in healthy men. Sexual desire rose from week 8 and remained higher until week 12, statistically independent of depression and anxiety scores. In the hormone analysis of the same study, LH, FSH, prolactin, 17-hydroxyprogesterone, testosterone and estradiol changed neither compared with placebo nor over time.

Sexual side effects of antidepressants

Dording and colleagues gave 45 women whose depression had remitted under SSRIs or SNRIs but who had sexual side effects 3.0 g of maca or placebo for 12 weeks. According to the MGH-SFQ, 30.0 percent under maca and 20.0 percent under placebo achieved remission. The advantage was seen mainly in postmenopausal women. Maca was well tolerated.

Mood and energy in lowlands and highlands

Gonzales-Arimborgo and colleagues studied 175 adults in Peru who received 3 g of red or black maca extract or placebo for 12 weeks. Mood, energy and health status improved compared with placebo; in people living in the highlands, the score for chronic mountain sickness also fell. Both extracts were well accepted, and no serious side effects occurred.

Where the data stop

All the studies mentioned are small, and almost all endpoints are questionnaires. Systematic reviews from 2010 and 2011 come to the same conclusion: the number, size and quality of the studies are not sufficient for firm statements. A 2026 meta-analysis of 14 studies on herbal remedies for erectile dysfunction saw saffron and ginseng in the lead and rated the evidence for maca as insufficient. A large part of the research also comes from one working group in Peru. On sperm quality, the results are inconsistent. In a study with 69 men, only sperm concentration rose; in one with 50 men there was no significant difference, and a meta-analysis of 5 studies found no established effect on concentration. Testosterone did not rise in any human study. For athletic performance there are hardly any human data: in a pilot study with 8 cyclists, maca was no better than placebo in a 40 km time trial, and a 2024 meta-analysis relies predominantly on animal experiments. Finally, not all maca is the same. Color, origin and processing change the constituents, and a result with a particular extract does not automatically apply to every powder.

Status, approval and legal

According to the EU Novel Food Catalogue, the maca tuber is not a novel food, because it was consumed to a significant degree before 1997. It may therefore be sold as a food and dietary supplement. There are no authorized health claims: the applications submitted on sexual desire, fertility, bones and energy are on EFSA’s list of on-hold botanical claims. There is no official maximum amount. In 2007, the BfR was unable to derive a safe intake level. The daily amounts of the products recorded at the time ranged between 400 and 5,000 mg, mostly 600 to 2,400 mg.

Safety

In the controlled studies over 12 to 16 weeks, maca was well tolerated, and no serious side effects were reported. The BfR, however, criticizes that no systematic safety studies are available. In animal experiments there were effects on the reproductive organs and indications of interactions with hormonal effects; in humans such effects have not been demonstrated so far. In a 90-day study in people with metabolic syndrome, the liver value AST and diastolic blood pressure rose slightly in the maca group; in another study, diastolic blood pressure fell. Maca contains alkaloids whose content varies greatly by product, in finished products from 56 to 598 ppm. Cell experiments showed a weak estrogen-like effect. Anyone who is pregnant, breastfeeding or has a hormone-dependent disease is therefore better off avoiding it. Anyone with blood pressure or liver disease should discuss intake with a physician.

Sources

• Gonzales et al., Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men, Andrologia 2002
• Gonzales et al., Effect of Lepidium meyenii (Maca) on serum reproductive hormone levels in adult healthy men, Journal of Endocrinology 2003
• Zenico et al., Subjective effects of Lepidium meyenii (Maca) extract on well-being and sexual performances in patients with mild erectile dysfunction, Andrologia 2009
• Dording et al., A double-blind placebo-controlled trial of maca root as treatment for antidepressant-induced sexual dysfunction in women, Evidence-Based Complementary and Alternative Medicine 2015
• Gonzales-Arimborgo et al., Acceptability, Safety, and Efficacy of Oral Administration of Extracts of Black or Red Maca, Pharmaceuticals 2016
• Brooks et al., Beneficial effects of Lepidium meyenii (Maca) on psychological symptoms and measures of sexual dysfunction in postmenopausal women, Menopause 2008
• Shin et al., Maca (L. meyenii) for improving sexual function: a systematic review, BMC Complementary and Alternative Medicine 2010
• Lee et al., Maca on semen quality parameters: A systematic review and meta-analysis, Frontiers in Pharmacology 2022
• BfR, risk assessment of maca-containing dietary supplements, opinion no. 024/2007 (German)
• European Commission, Novel Food Status Catalogue, Lepidium meyenii Walp.