Maca: The Andean Root With More Stories Than Data

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Maca (Lepidium meyenii) is a root vegetable from the Peruvian Andes, marketed as an aphrodisiac, fertility enhancer, and energy booster. It has a strong traditional reputation, a consumer following that has driven export demand, and a clinical evidence base that is smaller and more equivocal than its profile suggests.

The Sexual Function Evidence

A 2010 systematic review in BMC Complementary and Alternative Medicine analysed 4 RCTs of maca on sexual dysfunction. Evidence was limited but suggested modest benefit in SSRI-induced sexual dysfunction and in menopausal sexual dysfunction. Effect sizes were small and trials were small. Follow-up trials have been inconsistent.

Fertility Claims

Small trials have shown maca increases sperm count and motility in healthy men over 3–4 months. Effect sizes are modest, studies small, and female fertility evidence essentially absent. For documented infertility, maca is not a substitute for reproductive endocrinology evaluation.

Hormonal Effects

Despite marketing suggesting "hormone balancing," controlled studies generally show maca does not alter serum testosterone, estrogen, FSH, LH, or cortisol meaningfully. Its mechanism likely involves non-hormonal pathways (possibly related to macaenes and macamides, unique alkaloids).

Energy and Performance

Subjective energy claims are popular but poorly supported. Small cycling and endurance trials have shown minimal to no performance improvements. If energy benefit occurs, it is modest and mostly subjective.

Colour Variants and Quality

Maca is sold as yellow, red, and black varieties with different marketing claims (red for female hormone balance, black for male fertility, etc.). Evidence for variety-specific effects is weak. Peruvian-sourced, traditionally processed (gelatinised or cooked) maca is generally considered better tolerated than raw powder. Dose is typically 1.5–3 g/day.

Safety

Maca is generally safe at culinary-to-supplement doses, with main side effects being mild GI upset. Mild goitrogenic potential (like most cruciferous vegetables) — caution with thyroid conditions at high doses. Hormone-sensitive conditions warrant caution despite lack of clear hormonal activity.