Maca

Maca (Lepidium meyenii) is a Brassicaceae root cultivated on the Peruvian altiplano above 4,000 m, eaten as a food staple and used traditionally for stamina and fertility. Its distinctive compounds are the macamides — N-benzylamide alkaloids found in no other food plant.

Macamides and FAAH

Macamides are FAAH inhibitors and are reported as neuroprotective. Structurally they are fatty acid N-benzylamides, which is worth noticing: anandamide is itself a fatty acid ethanolamide. The macamides are structural analogues of the very substrate whose degrading enzyme they inhibit, which is a more coherent mechanistic story than most botanical enzyme claims can offer.

Macamide content depends heavily on post-harvest processing — traditional sun-drying over weeks generates them from precursor fatty acids and benzylamine. Fresh root has little; the traditional preparation is doing chemistry, not just preservation.

Colours

Yellow, red and black maca are separate phenotypes and are not interchangeable in the literature: black maca is the one associated in trials with memory and with sperm parameters, red with prostate outcomes in rodent studies. Most commercial product is yellow, the most abundant.

Gelatinised versus raw

Gelatinised maca has been heat- and pressure-treated to remove starch. This is standard in Peru for digestibility, and is not the same product as raw powder; the two behave differently in the gut and are frequently compared as though identical.

Evidence

Small human trials support effects on sexual desire — independent of testosterone, which maca does not appear to raise — and on menopausal symptoms, with the mechanism unresolved. Fertility and energy claims are weaker. The FAAH and neuroprotection work is preclinical.

Maca contains no plant sterols or hormones, contrary to a persistent claim; whatever it does, it does not do by supplying hormone.

Cautions

Goitrogens. As a Brassicaceae it contains glucosinolates, which matter in iodine deficiency and in thyroid conditions, particularly in raw form and at the high intakes some protocols use.
Hormone-sensitive conditions — maca is not oestrogenic, but it does affect menopausal symptoms by some route, and that route is not characterised.
Stimulation and sleep — commonly reported; taking it late is a common complaint.