Peruvian root crop with strong evidence for sexual function, menopausal symptoms, and physical performance. Non-hormonal mechanisms, phenotype-specific effects, but high product variability makes quality critical.
Traditions: Peruvian traditional medicine
Multiple traditions agree on use.
Used for energy, vitality, and fertility enhancement in high-altitude communities. Cultivated at 4,000-4,500 meters. Traditional knowledge distinguished color varieties (black, red, yellow) for different effects, later validated by phytochemical analysis.
Maca has strong evidence across sexual function, menopausal symptoms, and physical performance, but effects depend heavily on dose and phenotype. Most benefits occur through non-hormonal mechanisms - sexual improvements happen without testosterone changes, menopause relief without consistent estrogen changes. Product quality varies wildly (40-fold macamide variation between products), making third-party testing essential.
Large effect sizes: forced swimming 2.26, rota-rod 6.26, grip strength 5.23. Higher doses more effective (dose-response relationship).
3.0 g/day effective (ASEX score 22.8→16.9, p=0.028), 1.5 g/day ineffective in 12-week trial (n=16)
3.0 g/day gelatinized maca significantly improved AMS, IIEF, and IPSS scores in 80 men over 12 weeks
74-87% symptom alleviation with 2.0 g/day for 2 months (hot flushes, night sweats, interrupted sleep all p<0.01)
Taste: Earthy, slightly sweet, malty. Less bitter than most herbs. Mix with smoothies, oatmeal, or warm milk.
Gelatinized powder most studied. Divide into 2-3 doses with meals. Duration: 8-12 weeks for full effects.
Gelatinized powder in capsules. Choose phenotype: black for glucose, red for mood/energy, yellow for general use. Look for third-party testing.
Less common but effective in trials. Spray-dried extracts preserve phenotype differences.
Maca has something rare: strong convergence between traditional use and modern clinical trials, with multiple RCTs and meta-analyses across several outcomes. But there’s a critical nuance most people miss.
Strong evidence (multiple RCTs):
Moderate evidence:
Insufficient evidence:
The critical discovery: Maca’s sexual and menopausal benefits occur without testosterone or estrogen changes in most studies. Gonzales 2002 found sexual desire improvements independent of hormone changes (testosterone p=NS) [2]. Brooks 2008 showed sexual dysfunction reduction with no changes in estradiol, FSH, LH, or SHBG [10]. This is a non-hormonal mechanism - probably neurotransmitter modulation or central nervous system effects.
The exception: Meissner 2006b showed increased estradiol and suppressed FSH/LH in postmenopausal women [11], but Brooks 2008 contradicted this. The hormone effects appear variable and context-dependent - don’t assume maca “raises hormones.”
Phenotype matters: Black maca has highest macamides and fatty acids, superior for glucose metabolism. Red maca better for mood and energy. Yellow maca intermediate [7]. Traditional users distinguished these centuries before phytochemical analysis confirmed it [12].
Product quality is everything: Commercial products range from 69-2738 μg/g macamides - that’s a 40-fold variation [12]. You could buy maca that works powerfully or does nothing, depending on macamide content. Third-party testing non-negotiable.
Peruvian Andes (pre-Columbian to present):
Modern validation of traditional knowledge:
Not found in:
Why geographically limited: Grows only at high altitude (4,000-4,500m) in specific Andean conditions. Cultural knowledge remained isolated in indigenous communities until modern era.
Pharmacopoeia status: No WHO or Commission E monographs. USP-NF monographs in development since 2009 [13]. Recognized as “recorded food use” by UK MHRA, Class 1 medicine in Australia/NZ [12].
Processing evolution: Traditional sun-drying influences macamide formation through enzymatic degradation and lipid hydrolysis [12]. Modern gelatinization (heating in water) claimed to improve digestibility, but no studies directly compare gelatinized vs raw for bioactivity [12]. Brooks 2008 showed efficacy with non-gelatinized powder at 3.5 g/day [10].
Gelatinized powder (most studied):
Capsules (convenient):
Dry extract (less common):
Week 1-2: 2.0 g/day
Week 3-8: 3.0 g/day
Week 9+: Up to 3.5 g/day if needed
Don’t expect quick results. This isn’t caffeine or Viagra. Effects build over weeks.
| Goal | Phenotype | Dose | Evidence |
|---|---|---|---|
| Blood glucose control | Black maca | 3.0 g/day | RCT (n=175) |
| Mood, energy, vitality | Red maca | 3.0 g/day | RCT (n=175) |
| Sexual function (general) | Yellow or mixed | 2.0-3.0 g/day | Multiple RCTs |
| Menopausal symptoms | Yellow or mixed | 2.0-3.5 g/day | Multiple RCTs |
| Athletic performance | Black maca (highest macamides) | 2.0-3.5 g/day | Meta-analysis |
If phenotype not specified on product, assume mixed or yellow maca.
Baseline (1 week before starting):
During trial (weeks 1-12): Track the same markers daily. Compare:
What to expect if it’s working:
RED FLAGS - Stop immediately:
What they report: “Libido came back after 2 months,” “hot flushes reduced by 80%,” “recovery from workouts noticeably faster,” “energy more stable throughout day.”
Product quality is critical: The 40-fold variation in commercial products means choosing a verified source determines whether you get therapeutic effects or nothing [12]. Only use third-party tested products.
Maca tastes earthy, slightly sweet, malty - like a cross between butterscotch and roasted nuts with a hint of radish. Less bitter than most medicinal herbs. Some describe it as “burnt caramel meets root vegetable.”
How to use:
If you can’t tolerate the taste, capsules work equally well and are clinically validated.
The problem: Commercial maca products range from 69-2738 μg/g macamides - a 40-fold variation [12]. Some products are potent, others essentially inert. Without third-party testing, you’re gambling.
What to look for:
Red flags - avoid:
Why this matters more than most herbs: Unlike standardized extracts of other herbs, maca powder varies wildly based on growing conditions, harvest timing, drying methods, and storage [12]. The product you buy might have 10x the bioactive content of another, or 1/10th. Quality testing is the only way to know.
Maca works through a non-hormonal mechanism most people don’t understand. It improves sexual function without changing testosterone. It helps menopause without consistently raising estrogen. This makes it safer than hormone therapy but means your expectations should adjust - it’s not “raising” anything, it’s modulating central pathways.
When it works: Gradual improvements over 8-12 weeks in sexual desire, menopausal symptoms, physical endurance, and energy. About 74-87% response rate for menopausal symptoms [3]. Sexual function improvements significant but take patience.
When it doesn’t: You bought a low-quality product (most common reason), or you’re seeking immediate effects (wrong timeframe), or you have optimal baseline function already.
Dose matters: 1.5 g/day ineffective, 3.0 g/day effective for SSRI-induced sexual dysfunction [1]. Higher doses consistently better for physical performance [4]. Don’t underdose.
Phenotype matters: Black maca for glucose, red maca for mood/energy. If product doesn’t specify, results less predictable.
Start with 2.0 g/day gelatinized powder (divided, with meals), increase to 3.0 g/day after 1-2 weeks, track for 8-12 weeks before judging efficacy. Choose third-party tested products with specified phenotype. Be patient - effects build slowly but can be substantial.
The traditional knowledge was right: this root enhances vitality, sexual function, and endurance. Modern science confirmed it and showed it’s not through hormones - it’s something more subtle and arguably safer.
Duration: Minimum 8 weeks for sexual/menopausal benefits, 4-12 weeks for physical performance. Effects build over time - don't expect immediate results.
What to notice:
Start with 2.0 g/day divided into 2 doses with meals. Increase to 3.0 g/day after 1-2 weeks if well tolerated. Choose phenotype based on goal: black maca for glucose metabolism, red maca for mood and energy, yellow maca for general use. Effects are dose-dependent - higher doses (up to 3.5 g/day) more effective but start low. Individual variation exists but lower than many adaptogens. Track baseline symptoms for 1 week before starting to assess changes objectively.
Generally considered: safe
Contraindications:
Pregnancy/Nursing: Insufficient data for pregnancy and lactation. Traditional use in Peru suggests safety, but modern precautionary principle: avoid during pregnancy and breastfeeding due to lack of formal safety studies [13,14].
Excellent safety profile. USP 2009 review found no serious adverse events [13]. LiverTox database shows no liver injury cases [15]. Most adverse effects mild and transient: GI upset (most common), headache, irritability [14]. Well tolerated at 2.0-3.5 g/day for 12 weeks in trials [1,3,10]. No documented drug interactions [13,14]. Theoretical beneficial interactions with antihypertensives (may lower BP) and diabetes medications (black maca may lower glucose) - monitor if on these medications [3,7]. Product quality critical: commercial products show 40-fold variation in macamide content (69-2738 μg/g) [12]. Choose third-party tested products to ensure bioactive content and absence of contaminants. No long-term studies beyond 12 weeks, but centuries of traditional use suggest safety.