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Maca root is the dried root of Lepidium meyenii, a plant in the mustard family that grows high in the Peruvian Andes and has long been eaten there as a cooked food. As a supplement it is sold as powder, capsules and extracts, and marketed for energy, mood, libido and menopause. The honest summary: a handful of small trials found modest changes in self-reported scores, systematic reviews call the evidence limited, and maca does not appear to change sex hormone levels in men. Side effects seem uncommon, but safety in pregnancy is unknown and Memorial Sloan Kettering advises caution with hormone-sensitive cancers. Here is what the research shows and how to read a maca label.
Peptide Labs sells one supplement that lists maca root extract, but this article does not recommend it or any other product. It is general information, not medical advice.
Key Takeaways
- Maca is a root vegetable from the Peruvian Andes in the mustard family, traditionally eaten cooked.
- Reviews of small trials describe the evidence for sexual function and menopausal symptoms as limited.
- In men, maca did not change testosterone or estradiol levels in trials.
- Reported side effects are uncommon; one case report linked maca to a falsely high testosterone test.
- Safety in pregnancy and breastfeeding is not established; ask a clinician if you have a hormone-sensitive condition.
What is maca root?
Maca is the root of a small plant that grows in the harsh climate of the high Andes. In the central Peruvian Andes it has been eaten for centuries, usually after boiling. A 2012 review by Peruvian researcher Gustavo Gonzales notes that no toxic effects have been reported with that traditional cooked use. Roots come in yellow, red and black types, and supplement labels sometimes name the color.
Chemically, maca contains compounds called glucosinolates, the same family found in cabbage and broccoli, plus compounds called macamides. Memorial Sloan Kettering Cancer Center (MSKCC) lists its traditional uses as stamina, fertility, libido and menopause, but notes that only a few small human trials exist. Most of the more striking findings, such as better endurance or memory, come from animal studies.
Maca forms on supplement labels
| Form | What it is | What to check |
|---|---|---|
| Raw powder | Dried, ground root | Whether it says raw or gelatinized; source and testing |
| Gelatinized powder | Heat-processed root powder | The form used in a 2002 Peruvian trial; processing details vary by maker |
| Extract | Concentrated root extract, often in capsules | Extract ratio; whether the amount is shown |
| Blend ingredient | One item inside a proprietary blend | Blends usually hide how much maca is present |
Maca root benefits: what the research shows
Most claimed maca root benefits rest on small, short trials with self-reported outcomes. Here is how the main lines of evidence stack up.
| Area studied | Main evidence | What it found | Limits |
|---|---|---|---|
| Sexual desire and function | 2010 systematic review of 4 RCTs | Some trials reported changes in self-rated scores | Few, small trials; reviewers called evidence limited |
| Menopausal symptoms | 2011 systematic review of 4 RCTs | All four reported lower symptom scores | Very few rigorous trials; safety not proven |
| Mood scores | Small crossover trial in 14 postmenopausal women | Lower anxiety and depression subscale scores | Six weeks per phase; preliminary |
| Semen quality | 2022 meta-analysis of 5 RCTs | Unclear; no significant change in sperm concentration | Too few trials |
| Physical performance | 2024 meta-analysis of 21 studies | Large effects, mostly in animal tests | Few human data |
Libido research
Maca is heavily marketed for libido, so it is worth being precise. A 2010 systematic review found four randomized trials: two reported changes in self-rated sexual desire or function, one in cyclists found no effect, and the reviewers concluded the evidence was too limited to draw firm conclusions. A 2002 Peruvian trial in healthy men reported higher self-rated desire after eight weeks without any change in testosterone or estradiol. None of this shows that maca changes sexual performance, and maca is not a substitute for medical care. Sexual problems can have medical causes, including medicines, so they are worth raising with a clinician.
Maca for women
Research on maca for women has focused on menopause. A 2011 review in Maturitas found four small randomized trials in peri- and postmenopausal women, all reporting lower scores on standard symptom questionnaires, but it judged the evidence limited and noted that safety had not been proven. In a 2008 Australian crossover trial, 14 postmenopausal women had lower anxiety, depression and sexual symptom subscale scores while taking maca, with no change in estradiol, FSH or LH. A 2015 trial at Massachusetts General Hospital in 45 women with sexual side effects from antidepressants reported slightly higher response rates with maca, mainly in postmenopausal women. MSKCC notes that maca appeared to shift some hormone levels in women in some studies but not in others.
Hot flashes, low mood and sexual changes around menopause can have many causes. A clinician can explain options that have far stronger evidence than any herbal product.
Energy, stress and adaptogen marketing
Maca is often sold alongside so-called adaptogens. Our guides to ashwagandha, rhodiola and ginseng cover herbs with their own, separate evidence. Claims that maca lowers stress hormones are not backed by good human trials; our cortisol belly article explains why cortisol is rarely the reason for belly fat. A 2024 meta-analysis on physical performance found large effects, but its main measures were animal tests such as forced swimming and grip strength in rodents.
Maca side effects and who should be careful
Reported maca side effects are uncommon in trials, which were small and short. MSKCC lists subjective reports of altered menstrual cycles, moodiness, cramps, stomach irritation and insomnia. Other points:
- Lab tests: a case report describes a woman with prolonged bleeding between periods and a high testosterone result that MSKCC links to maca interfering with testosterone tests. Tell your clinician if you take maca before blood work.
- Hormone-sensitive conditions: MSKCC advises talking to your provider first if you have a hormone-sensitive cancer such as breast or uterine cancer.
- Pregnancy and breastfeeding: safety is not established; MSKCC says maca may not be safe for you.
- Thyroid: maca contains glucosinolates. The NIH Office of Dietary Supplements notes that goitrogens in foods such as cabbage and broccoli matter mainly for people with low iodine intake. We found no human studies showing maca affects thyroid function, but ask your clinician if you have a thyroid condition.
- Blood pressure medicines: in rats, maca strengthened the effect of losartan. Whether this happens in people is unknown, so mention maca to your prescriber.
- Blends: maca often appears inside stimulant formulas, where the caffeine is a bigger concern than the maca itself.
Maca root in supplements we carry
Only one product in our catalog lists maca. Zantrex Blue includes maca root extract as one of 13 ingredients in a proprietary blend led by yerba mate, guarana and caffeine, so the label does not show how much maca it contains. It is a high-stimulant product: the label says it is not for use under 18 or during pregnancy or nursing, and to consult a physician first if you take medication or are sensitive to stimulants. The product name mentions GLP-1, but it is a dietary supplement, not a GLP-1 medication. Anyone comparing products should look for the maca form, the amount and a third-party testing seal.
If you are curious about other trendy plant powders, our mushroom coffee guide looks at the evidence behind lion’s mane, chaga and reishi blends.
Frequently Asked Questions
What is maca root good for?
Maca is a traditional Andean food. Small trials reported modest changes in self-rated mood, menopausal symptoms and sexual desire, but reviewers describe the evidence as limited.
Does maca increase testosterone?
Trials in men found no change in testosterone or estradiol levels. One case report found maca may interfere with testosterone blood tests.
Is maca good for women?
Small trials in menopausal women reported lower symptom scores, but the studies were few and small and long-term safety has not been established.
What are the side effects of maca?
Side effects seem uncommon. Reports include menstrual changes, moodiness, cramps, stomach irritation and insomnia.
Can I take maca while pregnant?
Safety in pregnancy and breastfeeding has not been established, so talk with your clinician before using it.
Is maca safe with thyroid problems?
There are no human studies showing harm, but maca contains glucosinolates, so ask your clinician if you have a thyroid condition.
Questions about a label? Contact us or read our Buyer’s Guide. Follow the label and ask a healthcare provider before starting any supplement, especially if you take medicines. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Last reviewed October 2026.
Related guides: Ashwagandha Benefits, Side Effects and Safety: What Studies Show, Rhodiola Rosea: Benefits, Side Effects and How to Read the Label, Ginseng Benefits: Panax vs American Ginseng, Evidence and Side Effects.