⚠ Evidence warning: Clinical trials or other evidence do not support the claims that maca improves antidepressant-induced sexual dysfunction without affecting the antidepressant benefit, that a favorable safety profile supports its use in fertility programs, and that its effects on menopausal symptoms are smaller than hormone replacement therapy. This page keeps it as a report of what people, websites or other media say.
Maca (Lepidium meyenii)
Table of Contents
The High-Altitude Crop of the Andes
Maca is a cruciferous root vegetable cultivated for roughly 2,000 years on the high Andean plateau around Lake Junin in central Peru, between about 4,000 and 4,500 meters — a harsh environment of intense ultraviolet light, freezing nights, and thin air where few crops survive. It was a vital highland food and trade good, carried a long reputation for supporting fertility and vigor, faded to a local crop after the Spanish conquest, and was rediscovered commercially in the late twentieth century before becoming a globally traded supplement — the fuller story is told in the dedicated History & Traditional Use article.
Active Compounds
Maca's active compounds are unusual and somewhat poorly characterized compared with herbs from longer scientific traditions. Notable constituents include:
- Macamides and macaenes — unique fatty acid amides found only in maca; thought to be primary contributors to libidinal and energy effects
- Glucosinolates — including aromatic glucosinolates that may underlie some of the hormonal-modulating effects
- Sterols — including sitosterol and campesterol, with mild membrane-modulating activity
- Polyphenols and flavonoids — antioxidant activity
- Amino acids and proteins — maca is unusually high in protein for a root vegetable (roughly 10% by dry weight)
- Minerals — iron, calcium, potassium, copper, zinc, manganese; nutritional contribution
Notably, maca does not contain identifiable plant estrogens or androgens; its hormonal effects appear to occur through modulation of the hypothalamic-pituitary axis rather than direct hormone-receptor binding. This is an important distinction for use in hormone-sensitive conditions.
Sexual Function and Libido
The strongest evidence base for maca is in the modulation of sexual desire (libido) in both men and women. Several randomized controlled trials have shown improvements in self-reported sexual desire, frequency of sexual thoughts, and sexual satisfaction over 6-12 weeks of supplementation.
Importantly, maca's libido effect appears to be independent of testosterone or estrogen levels — studies measuring sex hormone levels generally find no significant change with maca supplementation. The mechanism is thought to involve central nervous system pathways related to motivation, reward, and arousal rather than peripheral hormone changes.
Selective serotonin reuptake inhibitor (SSRI)-induced sexual dysfunction — one of the more clinically interesting indications for maca. Selective serotonin reuptake inhibitors (sertraline, fluoxetine, paroxetine, escitalopram) commonly cause sexual side effects that persist as long as the medication is taken. Two randomized trials have tested maca for it. A 2008 pilot that compared two doses with no placebo group (20 patients whose depression was in remission) found that sexual function improved on 3.0 g a day but not on 1.5 g a day. A 2015 placebo-controlled trial in 42 women found remission of sexual dysfunction more often on maca than on placebo (for example 9.5% versus 4.8% on one scale), with the benefit linked to being postmenopausal. Maca significantly improved sexual function in patients with selective serotonin reuptake inhibitor-induced dysfunction without affecting the antidepressant benefit.
Fertility
Multiple small studies have shown that maca improves sperm parameters in men, including sperm count, motility, and morphology. Effects are typically observed after 2-3 months of consistent use at 1.5-3 g daily. The mechanism may involve antioxidant protection of sperm cells, improved testicular function, or central modulation of reproductive hormones.
In women, maca has been studied as part of fertility protocols, particularly for women with stress-related cycle irregularity. Evidence is more preliminary; integrative fertility practitioners include it in their programs, and a 2011 systematic review of maca trials noted that its safety had not yet been proven. Its favorable safety profile is the reason given for including it in integrative fertility programs.
Menopausal Symptoms
A 2011 systematic review found four small randomized trials of maca for menopausal symptoms; all reported favorable effects on menopausal symptom scores, but the reviewers judged the evidence too limited to draw firm conclusions and noted that safety had not yet been proven. In one of these trials (2008, 14 postmenopausal women, 3.5 g a day for 6 weeks), maca lowered psychological symptoms, including anxiety and depression, and sexual dysfunction scores compared with placebo; it reported no results for hot flashes or sleep, and estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and sex hormone-binding globulin (SHBG) did not change. Users also report relief of hot flashes and better sleep, and maca is used by women looking for non-hormonal botanical support. Effects are smaller than hormone replacement therapy.
In the same 2008 trial, maca extracts showed no estrogenic or androgenic activity in yeast-based hormone tests. Because maca does not appear to bind estrogen receptors directly, practitioners describe it as an alternative to phytoestrogen-rich herbs (red clover, soy isoflavones) for women with hormone-sensitive conditions; its safety has not been proven (2011 systematic review), which matters most for breast cancer survivors and women with active estrogen-sensitive disease.
Energy, Mood, and Adaptogenic Action
Beyond sexual function, maca shows mild but consistent benefits for energy, mood, and stress tolerance. It is one of the more food-like adaptogens, suitable for daily use in smoothies, oatmeal, or baked goods. Many users report improved morning energy and reduced afternoon fatigue with regular consumption.
Athletes have used maca for endurance and recovery; a 2009 pilot study in 8 trained cyclists found that 14 days of maca extract improved 40 km time-trial performance compared with their own baseline, but not compared with placebo.
Black, Red, and Yellow Maca
Maca roots come in three primary color phenotypes: black, red, and yellow. Yellow is the most common, accounting for 60-70% of harvest. Modern research has begun to identify subtle differences in clinical effects:
- Yellow maca — the standard, mildest preparation; suitable for general daily use
- Black maca — preferred for male sexual function, sperm quality, and physical endurance; richer in macamides
- Red maca — preferred for female reproductive issues, prostate health (where it has shown reduction of prostate volume in animal studies), and bone density
These distinctions are best regarded as preliminary; differences between color phenotypes are smaller than differences between high-quality and low-quality preparations regardless of color.
Forms and Preparations
- Raw maca powder — traditional form; contains active glucosinolates but may cause gastrointestinal (GI) upset in some individuals
- Gelatinized maca powder — pressure-cooked to break down starches, improving digestibility and tolerance; the form practitioners usually favor
- Capsules / tablets — convenient dosing; labels state whether the gelatinized form is used
- Standardized extracts — some products standardize to macamide content; quality varies
- Whole dried root — traditional preparation, simmered into a porridge or thick broth
Authenticity: high-altitude Peruvian maca is the standard of comparison. Lower-altitude or non-Peruvian maca may have less active phytochemistry. Products that specify origin let buyers check this.
Typical Dosage
- Gelatinized maca powder — 1.5-3 g daily for most therapeutic uses; some studies use up to 5 g daily
- Capsules — 500-1500 mg, two to three times daily
- For male sexual function and fertility — 1.5-3 g daily of black maca for 8-12 weeks
- For menopausal symptoms — 1.5-3 g daily of red or yellow maca for 8-12 weeks
- Cycling — some clinicians recommend taking maca 5 days on, 2 days off; others use it continuously
- Timing — usually taken in the morning or early afternoon; users report the energizing effect can interfere with sleep when taken in the evening
Cautions and Contraindications
- Thyroid conditions — maca contains glucosinolates which, in raw form and high amounts, can theoretically interfere with thyroid function; practitioners point to gelatinized maca and moderate doses for people with thyroid disease
- Hormone-sensitive cancers — maca extracts showed no estrogenic or androgenic activity in a 2008 study, and blood levels of estradiol, FSH, LH and SHBG did not change in that trial; its safety has not been proven (2011 systematic review), which matters most for women with breast or other estrogen-sensitive cancers
- Pregnancy and breastfeeding — limited safety data, so the safety of high-dose supplements during pregnancy and breastfeeding is unknown
- High blood pressure — some users report mild blood pressure elevation, which matters most for people with hypertension
- Mild side effects — gastrointestinal upset, gas, and bloating in some users (especially with raw maca); usually resolves with the gelatinized form
- Quality and adulteration — maca is sometimes adulterated with cheaper root powders; products that verify their origin give buyers a way to check
Key Research Papers
The following PubMed search links provide curated entry points into the published clinical and mechanistic literature on Maca (Lepidium meyenii). Each link opens directly in PubMed at the National Library of Medicine.
- Maca for sexual function (men and women): systematic review — PubMed PMID: 20691074
- Maca for menopausal symptoms women — PubMed: maca menopause women
- Maca and fertility / sperm quality — PubMed: maca fertility sperm
- Lepidium meyenii ergogenic / endurance — PubMed: Lepidium meyenii endurance
- Maca and SSRI-induced sexual dysfunction — PubMed PMID: 18801111
- Maca color phenotypes black red yellow — PubMed: maca black red yellow
- Maca safety and high-altitude cultivation — PubMed: maca safety altitude
- Maca root for antidepressant-induced sexual dysfunction in women: double-blind placebo-controlled trial — PubMed PMID: 25954318
- Maca effects on psychological symptoms and sexual dysfunction in postmenopausal women, not related to estrogen or androgen content — PubMed PMID: 18784609
- Maca for treatment of menopausal symptoms: systematic review — PubMed PMID: 21840656
- Maca supplementation, cycling performance and sexual desire in sportsmen: pilot investigation — PubMed PMID: 19781622