Maca
In short
Summary of findings for quick reference
As a crop, maca comes from the Andes. Its edible storage organ consists of the root and swollen lower stem, called the hypocotyl. Cobo’s 1653 chronicle records food use and its contemporary fertility reputation. The cited sources do not establish uninterrupted cultivation for at least 2000 years.
Yellow, red and black maca are colour forms, not established treatments for distinct complaints. Cultivation and processing affect composition. Gelatinised powder is heat-treated powder with gelatinised starch; it is not the same as a concentrated extract and does not automatically have better tolerability or proven safety in thyroid disease.
Human research is small and inconsistent. One male trial found increased self-reported sexual desire without a testosterone rise; that does not demonstrate improved fertility. Mood and endurance findings also apply only to the participants and preparations studied. Long-term safety and a generally effective dose remain insufficiently established.
Clinical evidence ↔ Historical significanceWe display two separate evidence categories: clinical evidence from modern trials and historical significance from documented healing tradition. Both are valuable, but they answer different questions.Read more
In every encyclopedia entry we evaluate two distinct categories of evidence. Clinical evidence as used in trials meets a narrower but scientifically essential bar. At the same time, the hundreds of thousands of plant species worldwide have only partially been captured and tested in modern studies.
Alongside the trial picture our researchers compile a comprehensive overview of where and since when a plant has been used across different traditions of natural medicine. When a plant has been used as a medicinal plant in many cultures across many generations, that historical significance deserves to be visible too.
Our position: a truly informative overview emerges only when both categories sit side by side. We communicate transparently what counts as what.
Overview
Maca is an Andean food crop in the Brassicaceae family, alongside broccoli and mustard. Its edible turnip-like storage organ consists of the root and swollen lower stem, the hypocotyl. In the Peruvian highlands it is traditionally dried and cooked or roasted before eating. The storage organs come in several colours, including yellow, red and black.
Maca is now sold as powder, heat-treated powder, capsules and extracts, and is added to chocolate or protein blends. Small studies have examined sexual desire and symptoms after menopause. They do not establish reliable benefits for libido, fertility or physical performance, and the various products cannot be treated as equivalent.
History
Maca has a long food history on the high plateaus of central Peru. The sources cited here do not securely date the beginning of cultivation. A clear written record is Bernabé Cobo’s Historia del Nuevo Mundo, completed in 1653: its maca chapter describes a stored food eaten cooked or roasted and reports a contemporary belief that it promoted fertility. This documents a historical belief, not efficacy.
In Europe, maca became known mainly through the more recent food and supplement trade, whose marketing draws on its Andean reputation as a strengthening food. This modern use should be distinguished from the traditional food culture. Long-standing food use also does not establish the same properties for concentrated extracts.
Mechanism
Studied constituents include macamides, fatty-acid derivatives, and glucosinolates. The latter also occur in other Brassicaceae and can release pungent compounds when broken down. Concentrations depend on colour type, cultivation and processing; they do not establish a universal ranking such as black maca always having the most macamides.
Many proposed mechanisms come from cell or animal experiments and do not establish effects of a particular powder in humans. In the Gonzales trial, reported sexual desire increased without higher testosterone or estradiol than placebo. The connection between individual constituents and possible clinical effects remains uncertain.
Shin and colleagues’ 2010 review included four small randomised sexual-function trials and found limited evidence, with too many methodological weaknesses for firm conclusions. Gonzales’ 2002 study assigned 57 healthy men to 1.5 or 3 g/day gelatinised maca or placebo for twelve weeks. Maca groups reported greater sexual desire from week eight, without differences in testosterone or estradiol versus placebo. This did not demonstrate better semen quality or fertility.
Stojanovska and colleagues studied 29 postmenopausal women in Hong Kong in 2015. Each received 3.3 g/day maca for six weeks and placebo for six weeks. Depressive symptoms and diastolic blood pressure decreased with maca, without changes in the measured hormones versus placebo. This small pilot does not establish broad relief of menopausal symptoms. In a separate trial of eight cyclists, the tested maca extract did not improve 40-km time-trial performance versus placebo after two weeks.
Evidence
| Outcome | Class | Grade | Effect | Studies | Refs |
|---|---|---|---|---|---|
| Sexual function in adultsFour small trials in Shin et al. (2010) provided limited, inconsistent evidence on sexual function. They included Gonzales et al. (2002): 57 healthy men received 1.5 or 3 g/day gelatinised maca or placebo for twelve weeks. The outcome was self-reported sexual desire, not successful conception, and measured hormones did not increase versus placebo. Small samples and differing products limit the findings.Adults with sexual dysfunction or healthy adults | EmergingEmerging research. Early small trials suggest an effect but await replication. | DEvidence quality grade D. Preliminary signal. A single small trial, pilot result, or laboratory or animal model. Clinical relevance unclear. This is an evidence rating, not a product endorsement. | Mixed Effect | [4][1] | |
| Energy and staminaMaca has a traditional reputation as a strengthening food. In Stone et al. (2009), eight trained cyclists received 2 g/day of a maca water extract or placebo for two weeks each. The extract did not outperform placebo on a 40-km cycling time trial. This does not establish greater everyday stamina or a specific benefit of black maca.Trained adult male cyclists; traditional food use provides context | TraditionalTraditional use. Long-standing folk practice or EMA HMPC traditional-use monograph. | DEvidence quality grade D. Preliminary signal. A single small trial, pilot result, or laboratory or animal model. Clinical relevance unclear. This is an evidence rating, not a product endorsement. | No clear performance advantage | [3] | |
| Menopausal symptomsStojanovska et al. (2015) compared six weeks of 3.3 g/day maca with six weeks of placebo in 29 women. Depressive symptoms and diastolic blood pressure decreased, while measured hormones, including estradiol and TSH, did not differ. This does not establish a reliable general treatment for menopausal symptoms.29 postmenopausal women in Hong Kong | TraditionalTraditional use. Long-standing folk practice or EMA HMPC traditional-use monograph. | DEvidence quality grade D. Preliminary signal. A single small trial, pilot result, or laboratory or animal model. Clinical relevance unclear. This is an evidence rating, not a product endorsement. | Findings from a small pilot study | [2] | |
| Andean food staple at altitudeMaca is historically documented as a Peruvian Andean food. Cobo’s 1653 account describes storage of the dried organ and consumption cooked or roasted. This establishes food history, not a clinical effect. The linked sources do not securely establish uninterrupted use for at least 2000 years.High-altitude Andean populations | TraditionalTraditional use. Long-standing folk practice or EMA HMPC traditional-use monograph. | DEvidence quality grade D. Preliminary signal. A single small trial, pilot result, or laboratory or animal model. Clinical relevance unclear. This is an evidence rating, not a product endorsement. | Traditional Use |
Usage
Forms and preparation
Maca powder can be stirred into porridge, a smoothie or warm milk. In gelatinised powder, heat and moisture have gelatinised the starch; the term does not mean added gelatin. Capsules may contain powder or an extract, while liquid extracts and maca-containing chocolate are other forms. Check the composition rather than relying on the name maca alone. Traditional preparation heats the dried storage organ before eating. Gelatinised powder is a modern heat-treated form, but that does not establish better tolerability or fewer thyroid-relevant constituents in every product. Colour is also not a reliable guide for treating particular complaints; recommendations such as red for menstrual concerns or black for endurance lack a sufficiently established basis.
Dosage
A generally effective daily dose has not been established. Gonzales studied 1.5 and 3 g/day gelatinised maca for twelve weeks; Stojanovska used 3.3 g/day for six weeks. These are study amounts for particular preparations, not general dosing recommendations. Follow the product label; powder and concentrated extracts cannot be exchanged gram for gram. Teaspoon measures are approximate because grind and fill level vary; use the stated gram quantity where provided. Reliable safety data for use over many months are limited. An eight-to-twelve-week cycle followed by a break is not an established regimen. Discuss longer-term supplementation with a clinician, especially for concentrated products.
Safety
Look-alikes
FAQs
What is the difference between yellow, red, and black Maca?
Yellow, red and black maca are colour forms of the same botanical species. Their composition can differ, but cultivation and processing also matter. Colour alone does not reliably predict a product’s effects. Clinical evidence is insufficient for fixed recommendations such as red for menstrual and bone concerns or black for energy.
Gelatinised powder or raw powder, which is better?
Gelatinised means that heat and moisture have gelatinised the starch. This changes the starch structure, but does not establish superior clinical effects. Traditional maca preparation heats the storage organ. The label gelatinised does not guarantee better tolerability or lower thyroid risk.
Is Maca safe for people with thyroid disease?
Safety in thyroid disease is insufficiently studied. Maca contains glucosinolates, a group of Brassicaceae constituents; this alone does not establish thyroid harm at usual maca intakes. Conversely, unchanged TSH in one small study does not prove safety in people with thyroid disease. Discuss supplementation with a clinician first; gelatinised powder is not automatically a safe alternative.
How long can I take Maca for?
Most studies described here lasted only a few weeks, which cannot establish safety for indefinite use. A fixed eight-to-twelve-week on/off cycle is also not scientifically established. For longer-term supplementation, seek medical advice and follow the specific product’s instructions. Stop if new symptoms develop.
7 sources.
- G. F. Gonzales; A. Córdova; K. Vega; A. Chung; A. Villena; C. Góñez; S. Castillo. Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men. 2002. doi:10.1046/j.1439-0272.2002.00519.x
- L. Stojanovska; C. Law; B. Lai; T. Chung; K. Nelson; S. Day; V. Apostolopoulos; C. Haines. Maca reduces blood pressure and depression, in a pilot study in postmenopausal women. 2015. doi:10.3109/13697137.2014.929649
- Mark Stone; Alvin Ibarra; Marc Roller; Andrea Zangara; Emma Stevenson. A pilot investigation into the effect of maca supplementation on physical activity and sexual desire in sportsmen. 2009. doi:10.1016/j.jep.2009.09.012
- Byung-Cheul Shin; Myeong Soo Lee; Eun Jin Yang; Hyun-Suk Lim; Edzard Ernst. Maca (L. meyenii) for improving sexual function: a systematic review. 2010. doi:10.1186/1472-6882-10-44
- Céline Clément; Diego A. Diaz Grados; Bharathi Avula; Ihklas A. Khan; Andrea C. Mayer; Dante D. Ponce Aguirre; Ivan Manrique; Michael Kreuzer. Influence of colour type and previous cultivation on secondary metabolites in hypocotyls and leaves of maca (Lepidium meyenii Walpers). 2010. doi:10.1002/jsfa.3896
- Health Canada. Maca – Lepidium meyenii. 2024. Source
- Bundesinstitut für Risikobewertung. Risikobewertung macahaltiger Nahrungsergänzungsmittel. 2007. Source
Legal notice: The depiction of historical significance and traditional use is context within our encyclopedia and not a health claim for any product, not a treatment promise, and not a substitute for medical advice. What may be stated on product labels, product pages, or in advertising is governed by the applicable legal requirements.