Maca

Lepidium meyenii

BrassicaceaeAndes Mountains of Peru and Bolivia, 3,500–4,500 m elevation

Description

overall appearance

Low-growing herbaceous biennial forming a basal rosette 10–20 cm tall with a flattened, turnip-like hypocotyl (the edible root-stem) 3–7 cm in diameter and 4–7 cm long. The entire aboveground portion rarely exceeds 20 cm in height, giving it a compact profile suited to windswept alpine conditions.

roots

Enlarged hypocotyl (commonly called the root) is the primary storage organ, varying in color from creamy-white and yellow to red, purple, and black; fleshy, dense, and high in nutrients. True roots extend below into rocky soil.

stem

Extremely short, compressed stem bearing a rosette; flowering stem (scape) emerges in second year, reaching 20–25 cm, branched at apex

leaves

Pinnately lobed, fleshy, spatula-shaped basal leaves 10–20 cm long and 2–3 cm wide; dark green with slightly wavy margins; form a ground-hugging rosette that withstands frost and hail

flowers

Tiny white to off-white, 4-petaled cruciform flowers 2–3 mm across; arranged in short terminal racemes; self-fertile

fruits/seeds

Small silicles (indehiscent pods) 4–5 mm long, each containing 2 oval reddish-brown seeds 2–3 mm in diameter

Active Compounds

Benzylglucosinolate (glucotropaeolin)Macaridine alkaloids (imidazole alkaloids)Macamides (N-benzyl fatty acid amides: N-benzyl-5-oxo-6E,8E-octadecadienamide)Meyenii sterols (β-sitosterol, campesterol, ergosterol)Glucosinolate hydrolysis products (isothiocyanates, nitriles)Flavonoids (kaempferol, myricetin)Anthocyanins (in red/black varieties: cyanidin-3-glucoside)Polyunsaturated fatty acids (linolenic acid, eicosenoic acid)

Traditional Uses

Andean tradition: consumed by Incan warriors before battle for energy and strength
Peruvian highland medicine: fertility enhancer for both men and women; root given to livestock to improve reproduction
Traditional use for altitude sickness and fatigue at high elevation among Quechua peoples
Post-menopausal symptom relief in Andean women's traditional practice
Cognitive support and memory enhancement in elderly Andean populations
Children's nutrition supplement in highland communities to support growth and development
Traditional treatment for osteoporosis and bone fragility in post-menopausal Andean women
Energy food and general tonic used continuously for thousands of years as staple crop

Modern Applications

Clinical evidence for improvement in sexual dysfunction: RCT showing 40% improvement in IIEF scores in men with mild erectile dysfunction (Zenico et al., 2009)
Hormone-independent improvement of menopausal symptoms; double-blind trial showed reduction in hot flushes and night sweats without altering estrogen or FSH levels (Meissner et al., 2006)
Sperm quality improvement: meta-analysis of 4 RCTs showing increased sperm concentration and motility
Mood and energy: pilot study of postmenopausal women showed significant reduction in anxiety and depression scores
Bone density support via glucosinolate-derived compounds; animal studies show protection against osteoporosis
Adaptogenic activity: modulation of HPA axis stress response demonstrated in animal models
Sports performance: pilot RCT in cyclists showed improved 40 km time trial performance after 14 days
Neuroprotection via macamide inhibition of fatty acid amide hydrolase (FAAH)

⚠️ Safety Information

Contraindications

Thyroid disorders: glucosinolates may be goitrogenic; avoid in hypothyroidism or goiter without medical supervision
Hormone-sensitive conditions (breast, uterine, ovarian cancer, endometriosis): estrogenic potential remains debated; caution advised
Pregnancy and lactation: insufficient safety data; traditional use was as fertility aid, not during pregnancy
Children under 12: no established pediatric dosing for supplements

Side Effects

Gastrointestinal discomfort (bloating, gas, nausea) especially with raw (non-gelatinized) powder at doses >3 g/day
Insomnia or restlessness if taken in the evening due to stimulant properties
Increased libido (generally desired, but note in patients with sexual compulsion history)
Mild headache reported in first 1–2 weeks of use

Drug Interactions

Thyroid medications (levothyroxine): glucosinolates may reduce efficacy; monitor thyroid function
Hormone therapies (HRT, oral contraceptives, tamoxifen): potential additive or antagonistic hormonal effects
Anticoagulants (warfarin): theoretical interaction via vitamin K content; monitor INR
Antihypertensives: mild hypotensive effect observed in animal studies; monitor blood pressure