Common Names
- Maca-maca
- Maino
- Ayak chichira
- Ayak willku
For Patients & Caregivers
How It Works
Maca may increase sexual function but it has not been shown to be effective against cancer.
Maca has been used traditionally to improve stamina and sexual functioning. Studies have shown that maca may help to increase libido and improve athletic performance. It may also affect some hormone levels in the blood. Further study is warranted.
Purported Uses
-
To treat infertility
No clinical trials support this use. -
To improve sexual performance
The evidence to support the use of maca in improving sexual function is limited. A few clinical trials showed increase in sexual desire, sperm count, and motility. It may also improve sexual dysfunction cause by antidepressant use or menopause. More studies are warranted. -
To improve strength and stamina
A small study suggests it may improve performance in athletes, but more study is needed. -
To treat cancer
Scientific evidence is lacking to support this claim.
Side Effects
Unverified possible reactions include: altered menstrual cycles, moodiness, cramps, gastritis and insomnia
Case report
- Prolonged bleeding outside of regular menstruation and high lab levels of testosterone: A woman in her thirties ingested 1 tsp daily of maca powder dissolved in milk to improve energy and libido. Bleeding began within a few weeks of this regimen and improved after she stopped taking maca. Her high blood levels of testosterone returned to normal 1 month after she stopped taking maca.
For Healthcare Professionals
Clinical Summary
Maca is a nutritionally valuable plant native to Peru that grows in harsh climates above 4,000 feet. It has been used traditionally to enhance fertility and sexual performance in both men and women and to relieve menopausal symptoms (1). Maca has also been purported to treat cancer and to improve stamina in cancer patients.
In vitro, maca or its constituents have demonstrated antiviral (17), antioxidant (18), anti-inflammatory, analgesic, or neuroprotective (19) activities.
Animal studies indicate that maca increases endurance (6), enhances sexual function (2) (5), and improves scopolamine-induced memory deficits (14). It also demonstrated antidepressant (20) and postmenopausal hormone-modulating (21) effects.
Only a few small trials have evaluated maca for its effects in humans. Maca consumption was associated with lower serum IL-6 levels and higher health status (22). In men, maca supplementation increased libido (3), sperm production and motility (4), and enhanced subjective sexual well-being (11). Another preliminary study suggests it may also improve athletic performance (23). In women, several studies suggest that maca improves both antidepressant- and menopause-induced sexual dysfunction (12) (24) (25) (26). A study in Chinese postmenopausal women showed neither hormonal nor immunological effects, but did appear to reduce depressive symptoms and diastolic blood pressure (27). However, systematic reviews have deemed the evidence on maca for sexual dysfunction (13) (28) (29) or for alleviating menopausal symptoms (15) to be limited and requiring further research. Another review indicates that maca is not an effective anti-aging agent (16).
A case report showed maca may interfere with testosterone immunoassays (30).
Purported Uses
Mechanism of Action
Maca contains glucosinolates, mostly benzylglucosinolate, along with hydroxy or methoxylated benzyl derivatives and tryptophan-derived compounds, and depending on the phenotype (red, yellow, purple or black) may be associated different biological effects (31).
In vitro, both methanolic and aqueous extracts of maca exhibit estrogenic activity (10). A methanol maca extract demonstrated antiviral activity against Flu-A and Flu-B viruses (17). An isolated N‑alkylamide from maca root was found to possess both direct and indirect cannabimimetic actions (32). Maca polysaccharides demonstrated radical scavenging activity (18). Macamides, normally not present in fresh plants but introduced during traditional drying practices (31), are fatty acid amide hydrolase (FAAH) inhibitors, and act on the central nervous system by modulating the release of neurotransmitters (19). Antidepressant-like effects were associated with activation of both noradrenergic and dopaminergic systems and attenuation of oxidative stress (20).
In animal models, maca powder derived from tubers enhanced serum luteinizing hormone (LH) levels in female rats during the proestrus LH surge in a dose-dependent manner, suggesting it may enhance fertility (33). In postmenopausal models, maca modulates hormone levels particularly by decreasing follicle-stimulating hormone (FSH) levels (21).
In humans, although maca does not affect serum levels of LH, FSH, prolactin, testosterone, or estradiol in men (4) (9), it appears to modulate some hormone levels in women in some studies (24) (26) but not others (25) (27). Increased LH and decreased FSH that corresponded with improved sexual functioning in postmenopausal women are potentially attributed to a negative feedback loop, resulting in increased androgen production (24) (26). It may also exert androgenic effects at the testosterone receptor on target organs without affecting testosterone or gonadotrophin levels (24) (30). At the same time, the benefits of maca for antidepressant-induced sexual dysfunction in women may be more a function of advancing age rather than menopausal status, as there was no correlation with estrogen levels (24).
Adverse Reactions
Subjective reports of altered menstrual cycles, moodiness, cramps, gastritis, and insomnia (34).
Flu-like symptoms and vomiting report were reported in one clinical study. However, it is unclear if these were caused by maca (24).
Case report
Prolonged intermenstrual bleeding and markedly elevated total plasma testosterone: In a white female in her thirties from ingesting maca powder 1 tsp daily dissolved in milk to improve energy levels and libido (30).
Herb Lab Interactions
Maca may interfere with testosterone immunoassays (30).