Bitter Melon Peptide (mcIRBP-19 / MAP30) for Type 2 Diabetes
Verdict: Published with Warning
Across 5 PubMed studies, the evidence for Bitter Melon Peptide (mcIRBP-19 / MAP30) in Type 2 Diabetes 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
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.56
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Published with Warning
Confidence
74%
Broadly consistent
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 = 0.556
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高階證據未達主導 (1 positive vs 1 negative)，由 raw_score 決定
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 1 個 hard + 1 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (5)L2 · primary research & systematic reviews
A randomized, double-blind, placebo-controlled trial to evaluate the hypoglycemic efficacy of the mcIRBP-19-containing Momordica charantia L. fruit extracts in the type 2 diabetic subjects
Finding: Statistically significant reduction in HbA1c of approximately 0.21%-0.5% in the mcIRBP-19 group vs placebo at 12 weeks (p<0.05); FPG also modestly reduced. No serious adverse events. Effect size smaller than pharmaceutical OHAs; sample very small.
View on PubMed Identification of the bioactive and consensus peptide motif from Momordica charantia insulin receptor-binding protein
Finding: mcIRBP-19 binds insulin receptor and lowers blood glucose in STZ-diabetic and db/db mouse models; identifies a 19-aa peptide as a candidate active fraction. Mechanistic/preclinical only; does not establish human efficacy.
View on PubMed Momordica charantia for type 2 diabetes mellitus (Cochrane Review)
Finding: Insufficient evidence on the effects of M. charantia for T2DM. Two trials of fair methodological quality found no statistically significant difference in HbA1c vs placebo or hypoglycemics; one small trial reported modest glucose-lowering. Conclusion: further high-quality studies needed before recommending bitter melon for T2DM.
View on PubMed The effect of bitter melon (Mormordica charantia) in patients with diabetes mellitus: a systematic review and meta-analysis.
Finding: Pooled analysis showed a small reduction in fasting plasma glucose with bitter melon vs placebo but the effect on HbA1c was not statistically significant. Authors note study heterogeneity, small sample sizes, short durations, and methodological limitations. Evidence is insufficient to recommend bitter melon as a hypoglycemic agent.
View on PubMed Hypoglycemic effect of bitter melon compared with metformin in newly diagnosed type 2 diabetes patients
Finding: Bitter melon 2000 mg/day produced a modest reduction in fructosamine vs placebo but the effect was substantially smaller than metformin 1000 mg/day. Lower doses showed no significant effect. Whole-fruit form, short duration; not generalizable to peptide isolate.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Cautious
Diabalance Diabetes Supplement ... bitter melon, dandelion, bilberry and ginkgo biloba ... marketed to help balance blood sugar levels for people with diabetes ... not generally recognized as safe and effective ... and therefore constitute new drugs source↗
L4d TW TFDA / 衛福部
Supportive
本產品經動物實驗結果顯示：有助於延緩飯後血糖上升，但人體試驗結果不顯著。本產品屬保健食品，不能取代藥品。 source↗
L5a NIH Office of Dietary Supplements
Cautious
In placebo controlled clinical trials in patients with diabetes or glucose intolerance, bitter melon extracts have had only a modest effect on serum glucose levels and little or no effect on fasting plasma glucose or hemoglobin A1c levels. source↗
L5c Cleveland Clinic
Cautious
Bitter melon may help lower blood sugar, but the research is mixed and the effect is modest at best. If you're already taking medication for diabetes, adding bitter melon could push your blood sugar too low. Talk to your doctor before trying it — it's not a replacement for the treatment plan you already have in place. source↗
L5d Harvard Health
Cautious
Many dietary supplements are marketed for diabetes, including bitter melon, chromium, and cinnamon. But there is little high-quality evidence that any of them meaningfully improve blood sugar control in people with type 2 diabetes, and some — particularly when combined with diabetes medications — can cause hypoglycemia. Food first, and talk with your doctor before adding any supplement. source↗
L5e Specialty Society (condition-mapped)
Against
Assess intake of supplements, as supplementation with micronutrients (e.g., vitamins and minerals, such as magnesium or chromium) or herbs or spices (e.g., cinnamon and aloe vera) is not recommended for glycemic benefits. source↗