Lepidium meyenii — maca — is a Peruvian root vegetable in the crucifer family (related to broccoli and cabbage) that has been cultivated at altitude in the Andes for millennia. At elevations above 4,000 meters, where the climate is extreme and the soil mineral-rich, maca has been used by Andean peoples as a food staple and as a traditional remedy for energy, stamina, fertility, and hormonal balance. Inca warriors reputedly consumed maca before battle for stamina — though were reportedly prohibited from consuming it after victory to protect conquered women from their heightened libido.
What Makes Maca Unique
Maca is nutritionally dense — high in protein, fiber, and multiple minerals including iron, iodine, calcium, and potassium. But its functional properties come from a class of compounds called macamides and macaenes — fatty acid derivatives found only in maca that interact with the endocannabinoid system and have hormonal modulating effects.
Maca also contains glucosinolates (as a crucifer), which convert to bioactive isothiocyanates in the body — compounds with documented antioxidant and hormonal effects. Critically, maca does not directly contain phytoestrogens or androgens. Its hormonal effects appear to be mediated through upstream regulatory mechanisms rather than direct hormone supplementation — a distinction that affects both its safety profile and its mechanism.
Clinical Evidence
Sexual Function and Libido
The most consistent clinical evidence for maca involves sexual function. A 2002 randomized double-blind study in the Asian Journal of Andrology found that 1500mg and 3000mg maca significantly improved self-reported sexual desire in healthy men compared to placebo after 8 weeks — without affecting testosterone or estrogen levels, confirming that the effect is not simply androgenic. A 2008 study in CNS Neuroscience and Therapeutics found maca to significantly improve SSRI-induced sexual dysfunction — a clinically meaningful finding given how common antidepressant sexual side effects are.
Menopausal Symptoms
Multiple studies have examined maca in perimenopausal and postmenopausal women. A 2008 double-blind, placebo-controlled trial in Menopause found that maca significantly reduced psychological symptoms of menopause (anxiety, depression) and reduced both diastolic blood pressure and body weight compared to placebo. A 2011 study found maca improved scores on the Greene Climacteric Scale (a validated menopause symptom measure) with particular effects on hot flash frequency and night sweating — without significantly altering estrogen or FSH levels.
Physical Performance and Mood
A 2009 pilot study in the Journal of Ethnopharmacology found that 14 days of maca supplementation improved time trial performance in male cyclists and also improved self-reported sexual desire. A 2016 randomized trial found maca significantly reduced self-reported fatigue and improved mood scores in postmenopausal women.
I'm 51 and went through surgical menopause. The hot flashes were unbearable and I didn't want to go on HRT immediately. My integrative gynecologist suggested maca. Within six weeks the hot flash frequency dropped by more than half. I don't know if I'd describe it as dramatic, but it was clinically meaningful to me and to my quality of life. — Maca consumer, 51, San Francisco
Colors and Their Differences
Maca comes in several phenotypic colors — yellow, red, and black — with differing bioactive compound profiles. Yellow maca is most common and most researched. Black maca has shown the strongest effects on sperm production and memory in animal studies. Red maca has demonstrated specific effects on prostate size reduction in animal models. Premium formulations increasingly specify maca color or use a blend of all three to capture the full spectrum of effects.
Gelatinized vs. Raw
Raw maca contains goitrogens (compounds that may interfere with thyroid function) and is difficult to digest. Gelatinization — a process of pressurized heat that removes the goitrogens and breaks down the starch — improves both safety and bioavailability. Gelatinized maca is the appropriate form for supplementation, particularly for anyone with thyroid concerns.