Legacy AI grade · Sources dated 2026-06-09. Not expert reviewed. Coverage is limited to the listed sources. About the new summary workflow

Maca for Fatigue

Verdict: Published with Warning

Across 5 PubMed studies, the evidence for Maca in Fatigue grades Tier C — weak evidence. Effective, but with safety or population caveats.

C 🟠 C Weak Evidence Published with Warning

🔬Why this grade7-layer evidence engine

Maca for fatigue lacks direct meta-analytic support. Adjudication correctly downgraded B→C citing null fatigue-primary trials. PMID 39796542 is a physical-performance meta-analysis, not a fatigue-outcome meta-analysis.

Positive signals in maca marketing often conflate energy, libido, and athletic performance with clinical fatigue relief. The evidence base is tiny and industry-linked.

Tier C reflects weak, surrogate-heavy evidence. Do not treat performance MA results as proof of fatigue benefit.

⚖️

Scoring transparency

All scores computed by a 7-layer evidence engine — fully auditable

Raw score 0.59

← counter-evidence / ineffectiveeffective / strong evidence →

Final grade

C · Published with Warning

Confidence

55%

Conflicting evidence

Evidence level

PMID 39796542 is physical-performance MA (animals+humans), not fatigue-outcome MA

How strongly each layer supports this effect

lower = less supportive

L1 ExamineGlobal benchmark

0.30

L5 Clinical bodiesAuthoritative stance

0.50

L11 AI re-checkIndependent read

0.50

L3 MechanismPlausibility

0.65

L2 PubMedPrimary literature

0.75

Against Mixed Supports

▸View the full decision path (audit trail)

compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.593
tier_from_score — 依分數區間映射至 tier letter
apply_hec_rules — 無高階證據可裁決
tier_strict_requirement_check — Tier 條件達標，未降階
detect_disputes — 偵測到 0 個 hard + 1 個 soft dispute
decide_status — 依 tier + dispute 結果決定 status

📄PubMed studies (5)L2 · primary research & systematic reviews

Acceptability, Safety, and Efficacy of Oral Administration of Extracts of Black or Red Maca in Adult Human Subjects: A RCT

PMID: 27548190 2016 Journal article n = 175

Finding: Red maca showed significant energy improvement vs placebo across all time points (p=0.0001); mood improvement at week 12 (p=0.01); HRQL improved in both maca groups by week 12 (p<0.01).

Government

View on PubMed

Beneficial effects of Lepidium meyenii (Maca) on psychological symptoms and measures of sexual dysfunction in postmenopausal women

PMID: 18784609 2008 RCT (double-blind) n = 14

Finding: Significant reduction in psychological symptom scores vs placebo (p<0.05); effects independent of estrogenic/androgenic activity.

🟠 Limited quality Government

View on PubMed

Maca reduces blood pressure and depression, in a pilot study in postmenopausal women

PMID: 24931003 2015 RCT (double-blind) n = 29

Finding: Significant decreases in diastolic blood pressure and depression scores after maca treatment; no effect on hormonal or immune markers.

🟠 Limited quality

View on PubMed

The Impact of Lepidium meyenii (MACA) Supplementation on Basketball-related Performance and Antifatigue Ability: A Double-blind Crossover Study

PMID: 40960048 2025 RCT (double-blind) n = 10

Finding: No significant differences between maca and placebo for fatigue index (p=0.266) or blood lactate clearance rate (p=0.258).

🟠 Limited quality

View on PubMed

Effects of Maca (Lepidium meyenii Walp.) on Physical Performance in Animals and Humans: A Systematic Review and Meta-Analysis

PMID: 39796542 2024 統合分析

Finding: Large pooled SMDs for anti-fatigue/performance outcomes (FST SMD=2.26, BLA SMD=-1.70), but animal and human data not disaggregated; human-specific effect sizes not reported separately.

🟠 Limited quality Academic Effect size: Pooled SMD 2.26 (FST, mixed animal/human); SMD -1.70 (blood lactic acid, mixed)

View on PubMed

🏛️Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …

L4a US FDA

Cautious

FDA advised consumers not to purchase or use Peru Maca. FDA laboratory analysis confirmed that Peru Maca contains sildenafil, the active ingredient in the FDA-approved prescription drug Viagra, used to treat erectile dysfunction. source↗

L4b EU EFSA

Cautious

L4d TW TFDA / 衛福部

Cautious

「Maca猛戈膠囊」（紳○實業有限公司製造）含有西地那非（Sildenafil citrate，即威而鋼成分）及他達拉非（Tadalafil，即犀利士成分），副作用包括降低血壓、頭痛、嘔吐、頭暈及暫時性視力模糊，並可能和某些藥物產生交互作用，衛生署呼籲消費者不要購買及服用誇大療效之產品。 source↗

✓PMID 100% verifiedevery citation checked via NCBI Entrez

🔬5 PubMed studiesindependently re-checked by multiple sub-agents

engine_version: v1.0 claim_id: CLM-COND-fatigue-INT-maca-001 繁體中文版 →