Serrapeptase for Chronic Bronchitis
Serrapeptase is not an evidence-based treatment for chronic bronchitis: the only positive data come from a single tiny open-label trial, while the strongest study available was negative and led the original manufacturer to pull the drug from the market.
Why this grade7-layer evidence engine
The entire positive case rests on one small open-label trial (Nakamura 2003, PMID 12911824, n=29) that used no placebo and no blinding. It reported less viscous sputum, fewer coughs, and better mucociliary clearance (index 13.3 to 24.4), but that design is highly vulnerable to placebo effect and observer bias, so the signal is weak. A 2013 systematic review of 24 efficacy studies (PMID 23380245) judged the whole serratiopeptidase evidence base to be of poor methodological quality.
Decisively, the best-quality data are negative. A 2020 review (PMID 33134103) documents that in 2011 the original maker, Takeda, voluntarily withdrew Danzen (serrapeptase) in Japan after a larger double-blind, placebo-controlled trial showed no benefit over placebo for difficult expectoration; Singapore phased it out for lack of substantive evidence. When the strongest study is negative and only a low-quality trial is positive, the honest conclusion is that it does not work.
Regulators and clinics reinforce this. The US FDA has never approved it and treats disease claims as marketing an unapproved drug, while the UK and EU classify serrapeptase as an unauthorised novel food that is illegal to sell as a supplement. No major respiratory body or clinic (Mayo, Cleveland Clinic, Harvard, ATS/CHEST) endorses it for airway mucus, and rare drug-induced lung injury reports add caution.
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 = 0.327
- 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 + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status