CHAMGAP
VERIFIEDPassed the Codex final verification and publication gate. Evidence-verification cutoff: 2026-09-08. AI was used for research and drafting; the existence of all 2 cited sources was verified at the original page, followed by blind grading, adversarial audit, and build validation. Methodology v1.0.
Verdict No. 3067 · Search date 2026-09-08 · Methodology v1.0

Oral single-ingredient berberine hydrochloride,
does it really help with Reduction of HbA1c in adults with type 2 diabetes?

30-Second Summary
C
Evidence Grade C · 54 · Safety warning
This verdict covers week-13 HbA1c in PREMOTE with industrially synthesized berberine hydrochloride 1.2 g/day and common gentamicin pretreatment only.
Warning. Gastrointestinal adverse effects were common and glucose-lowering drugs may compound hypoglycemia risk. Avoid in pregnancy, lactation, and infants, and review CYP2D6, CYP2C9, and CYP3A4 substrate medicines with a clinician.
What the
research shows
Grade C with 54 points. In the PREMOTE study, least-squares mean HbA1c change at week 13 was -0.99 percentage points in the berberine-only active-ingredient arm and -0.59 with double placebo, a between-group difference of -0.40 (95% CI -0.67 to -0.13; adjusted P=.0006). All groups first received seven days of gentamicin and the product was supplied by a manufacturer, limiting transfer to ordinary supplements.
What the
ads claim
Do not claim the same effect without the antibiotic pretreatment, replacement of metformin, cure or complication prevention, or interchangeability of all berberine products.
*

Useful facts when choosing a product

  • This verdict applies only to the displayed formulation, route, dose, duration, population, endpoint, and comparator.
  • Berberine hydrochloride, botanical extracts, combination formulas, dihydroberberine, other derivatives, and topical products are not interchangeable.
  • Warning. Gastrointestinal adverse effects were common and glucose-lowering drugs may compound hypoglycemia risk. Avoid in pregnancy, lactation, and infants, and review CYP2D6, CYP2C9, and CYP3A4 substrate medicines with a clinician.
ID

Chamgap Semantic Classification Code

Permanent code issued

S.berberine-hydrochloride.oral.hba1c.reduce.placebo

Supplements and nutraceuticals > Berberine hydrochloride > Oral > Type 2 diabetes HbA1c > Reduction claim > Same gentamicin pretreatment plus double placebo

Bound to week-13 HbA1c in PREMOTE with industrially synthesized berberine hydrochloride 1.2 g/day and common seven-day gentamicin pretreatment; probiotic combination, other glycemic outcomes, and dihydroberberine are separate. The code identifies the intervention and claim; it never contains the evidence grade, score, or safety result.

Download semantic index (JSON) · Codebook v1

Exact Claim Classification

These independent facets prevent evidence from different forms, routes, populations, effects, and comparators from being mixed.

Intervention classS · Supplement or nutraceutical
Canonical ingredient or interventionBerberine hydrochloride
Source or part usedIndustrially synthesized berberine hydrochloride; not a botanical extract
Formulation or processingSingle-ingredient berberine hydrochloride tablets
RouteOral
Dose600 mg twice daily (1.2 g/day)
DurationSeven-day gentamicin pretreatment followed by 12 weeks of trial agent; week-13 assessment
PopulationAdults with type 2 diabetes
Effect or conditionLower HbA1c
Primary endpointBetween-group difference in absolute HbA1c change at week 13
ComparatorBerberine placebo plus probiotic placebo after the same gentamicin pretreatment
Duplicate-detection keyBerberine hydrochloride|Single-ingredient berberine hydrochloride tablets|Oral|Adults with type 2 diabetes|Lower HbA1c|Seven-day gentamicin pretreatment followed by 12 weeks of trial agent; week-13 assessment
Gap Measurement · Verdict 3067 · C 54
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

The PREMOTE paper and NCT02861261 registration were checked against the 2008 pilot; the probiotic-combination arm, dihydroberberine, and combination formulas were excluded.

02

Why this is classified as C (54)

Axes are S/R1/I1/E+/B0/CX. A prespecified primary HbA1c endpoint, precise favorable contrast, and low missingness are strengths, but the surrogate endpoint, single study lineage, and product support yield C/54.

Counterpoint. A 2008 36-person metformin-controlled pilot mainly documented within-group change and was not counted as independent confirmation of this placebo contract.

Rejudgment record. Independent Codex cross-check — One formulation, route, population, claim, principal endpoint, and comparator

Scoring profile behind this grade
EndpointSSurrogate marker - laboratory or imaging measures
ReplicationR1Single confirmatory trial
IndependenceI1Mixed funding sources
Effect sizeE+Meets the clinically important threshold
PrecisionCXNo pooled confidence interval could be confirmed

The scoring table and the verdict agree (C).

Cross-check — AI research and Codex final gate

AI was used for research and drafting. Blind grading, adversarial audit, and the methodology boundary rules were then reapplied before Codex performed the final evidence, grade, copy, and build checks. If a grade cannot be narrowed, both evidence positions and their reasons are published.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Gut microbiome-related effects of berberine and probiotics on type 2 diabetes (the PREMOTE study)Design, allocation, masking, endpoint hierarchy, and analysis set were independently checked.391Funding, product support, employee authorship, and conflicts were assessed separately.The principal endpoint contract is preserved; other outcomes remain separate.Verified estimates are preserved; missing confidence intervals were not invented.Evidence weight reflects directness, formulation match, hierarchy, and reporting limitations.
Efficacy of berberine in patients with type 2 diabetes mellitusDesign, allocation, masking, endpoint hierarchy, and analysis set were independently checked.16Funding, product support, employee authorship, and conflicts were assessed separately.The principal endpoint contract is preserved; other outcomes remain separate.Verified estimates are preserved; missing confidence intervals were not invented.Evidence weight reflects directness, formulation match, hierarchy, and reporting limitations.
§

Receipt — 2 References

All 2 cited sources were verified for existence at the original page (as of 2026-09-08).

Zhang Y et al. Nat Commun. 2020;11:5015. PMID: 33024120. PMCID: PMC7538905. DOI: 10.1038/s41467-020-18414-8. NCT02861261.
checked
Yin J, Xing H, Ye J. Metabolism. 2008;57:712-717. PMID: 18442638. PMCID: PMC2410097. DOI: 10.1016/j.metabol.2008.01.013.
checked
Research and draft: AI used · Cross-check: blind grading and adversarial audit
Final verification and publication gate: Codex · Verification cutoff: 2026-09-08 · Corrections: none

Cite this verdict

Berberine Hydrochloride for Type 2 Diabetes HbA1c—The PREMOTE Trial Found a -0.40-Percentage-Point Difference at Week 13 Evidence Grade C card
[Chamgap] Berberine Hydrochloride for Type 2 Diabetes HbA1c—The PREMOTE Trial Found a -0.40-Percentage-Point Difference at Week 13 — Evidence Grade C·54. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/blood-sugar/berberine-hydrochloride-type-2-diabetes-hba1c/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

!

What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.