Alpha-Lipoic Acid for Neuropathy
Alpha-lipoic acid earns a preliminary (Tier B) rating for easing the symptoms of diabetic peripheral neuropathy, but the convincing evidence comes from intravenous dosing; the oral capsules people actually buy show only a small, often clinically negligible effect and do not improve objective nerve function.
Why this grade7-layer evidence engine
Four meta-analyses of more than 4,000 patients consistently link alpha-lipoic acid to symptom relief, which underpins the B grade. Intravenous ALA at 600 mg/day for three weeks produced clinically meaningful gains: a 24% relative improvement in Total Symptom Score and a higher responder rate (PMID 14984445), a pooled TSS drop of -2.81 (PMID 22331979), and a large effect of SMD -3.59 (PMID 37933068).
The grade sits at the low end of B because the benefit is route-dependent and largely subjective. The oral form sold as a supplement shows only a small TSS effect (SMD -0.46) and no significant change on nerve-conduction or impairment measures (PMID 37933068, PMID 37630823); the 2012 analysis found oral ALA statistically significant but below the threshold for clinical relevance (PMID 22331979). Many foundational trials were funded by an ALA manufacturer.
Authorities are accordingly cautious rather than endorsing. The UK NHS says the evidence 'is not always clear,' Mayo Clinic calls results 'mixed' and wants larger studies, EU EFSA rejected a nerve-protection health claim, and the US FDA has never approved ALA to treat disease. Standard glycemic control and first-line neuropathic-pain drugs remain the evidence-backed options.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸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 = 0.558
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (3 篇 > 0 negative)
- 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