Coenzyme Q10 for Parkinson
Verdict: Counter-Evidence
Across 6 PubMed studies, the evidence for Coenzyme Q10 in Parkinson grades Tier D — counter-evidence. High-quality evidence indicates it is not effective (or is harmful) for this use.
D 🔴 D Counter-Evidence Counter-Evidence
Why this grade7-layer evidence engine
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Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.27
D
C
B
A
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← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
D · Counter-Evidence
Confidence
87%
Highly consistent evidence
Evidence level
E1
Cochrane high-quality SR/MA
▸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 = 0.272
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 negative 主導 (2 negative > 0 positive)，下層 RCT 不能推翻
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (6)L2 · primary research & systematic reviews
A randomized clinical trial of high-dosage coenzyme Q10 in early Parkinson disease: no evidence of benefit
Finding: The pivotal NIH-funded Phase III QE3 trial was terminated for futility: adjusted mean UPDRS worsening was 6.9 points on placebo vs 7.5 points on 1200 mg/day (P=.49) and 8.0 points on 2400 mg/day (P=.21), i.e. no benefit and a slight adverse trend.
View on PubMed The efficacy and safety of coenzyme Q10 in Parkinson's disease: a meta-analysis of randomized controlled trials
Finding: Meta-analysis of 8 sham-controlled RCTs (n=899) found no significant motor benefit, with a pooled weighted mean difference of 1.02 on UPDRS-III (p=0.54); CoQ10 was safe and well tolerated but cannot be recommended for routine PD treatment.
View on PubMed Coenzyme Q10 for Patients with Parkinson's Disease: A Systematic Review and Meta-Analysis
Finding: Pooling 5 RCTs (n=981), CoQ10 produced no change in total UPDRS (SMD -0.05, 95% CI -0.10 to 0.15), with the authors concluding it 'does not slow functional decline nor provide any symptomatic benefit' in PD.
View on PubMed Coenzyme Q10 for Parkinson's disease (Cochrane systematic review; subsequently WITHDRAWN in 2012, PMID 22592726)
Finding: This 2011 Cochrane review of 4 placebo-controlled trials (n=452, 1200 mg/d for 16 months) reported a positive ADL/UPDRS trend but stressed it 'needs to be further confirmed by larger sample'; the review was formally WITHDRAWN in 2012 (PMID 22592726) and is superseded by the later negative Phase III RCT and meta-analyses.
View on PubMed Coenzyme Q10 and Parkinsonian Syndromes: A Systematic Review
Finding: This 2022 systematic review concluded prior meta-analyses show 'a lack of improvement in patients with early PD', that PSP results are only preliminary, and that any role in MSA or selected PD subgroups 'deserves future studies' — i.e. not supportive of routine use.
View on PubMed Randomized, double-blind, placebo-controlled pilot trial of reduced coenzyme Q10 for Parkinson's disease
Finding: This small pilot (n=48) found a significant improvement only in the wearing-off subgroup (total UPDRS -4.2 ± 8.2 in ubiquinol arm, p<0.05) while the early-PD subgroup showed no clear benefit; underpowered and not replicated in larger trials.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Cautious
not generally recognized as safe and effective for the referenced uses and therefore are considered "new drugs" source↗
L4b EU EFSA
Against
a cause and effect relationship has not been established between the consumption of coenzyme Q10 and the claimed effects source↗
L4c UK NHS
Cautious
Advise people with migraine that the food supplement riboflavin (400 mg once a day) may be effective in reducing migraine frequency and intensity for some people. source↗
L4d TW TFDA / 衛福部
Cautious
訂定「食品原料輔酵素Q10 (Coenzyme Q10)之使用限制及標示規定」 source↗
L5b Mayo Clinic
Against
Taking even high doses of CoQ10 doesn't seem to help with Parkinson's disease symptoms. Coenzyme Q10 was safe and well tolerated in this population, but showed no evidence of clinical benefit. source↗
L5e Specialty Society (condition-mapped)
Against
their study of long-term, high-dosage CoQ10 treatment was halted prematurely because it showed no clinical benefit for PD... Although the current results tell us that CoQ10 may not be the answer we were hoping for, we can look optimistically to a robust pipeline of therapeutic approaches now nearing or entering the clinic. source↗