CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-18). The draft was written by AI, the existence of all 4 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 484 · Search date 2026-07-18 · Methodology v0.6

Zinc L-carnosine,
does it really help with Gastric-mucosal protection and gastric-ulcer healing?

30-Second Summary
C
Evidence Grade C · 50 · Safety caution
Pharmaceutical and combination-treatment evidence cannot be converted into broad standalone supplement claims of gastrointestinal barrier repair
What the
research shows
Polaprezinc has randomized human trials evaluating endoscopic gastric-ulcer healing and symptoms, and trials found higher Helicobacter pylori eradication rates when it was added to standard therapy. The evidence is centered on an older Japanese medicine, active-comparator studies, and combination therapy with antibiotics and acid suppression. Attribution to a standalone supplement for general barrier repair is weak, supporting C.
What the
ads claim
Marketing claims coating of the stomach, regeneration of damaged barriers, and repair of leaky gut. Clinical evidence mainly concerns pharmaceutical-dose polaprezinc in Japan or China, diagnosed gastric ulcers, active comparators, or antibiotic combination treatment. This differs from long-term standalone PepZin GI use for general barrier repair.
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Useful facts when choosing a product

  • Prescription polaprezinc products and imported zinc L-carnosine supplements may be distributed in Korea, and medicines must be distinguished from dietary supplements.
  • A common clinical gastric-ulcer dose is polaprezinc 150 mg/day as 75 mg twice daily.
  • Products marketed as PepZin GI may differ in complex weight and elemental zinc, so both values require checking.
  • Long-term high zinc intake can cause copper deficiency and gastrointestinal effects, and a supplement cannot replace Helicobacter pylori eradication therapy.
Gap Measurement · Verdict 484 · C 50
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

A 1992 Japanese multicenter double-blind trial in 258 patients compared polaprezinc 150 mg/day with cetraxate 800 mg/day and reported eight-week endoscopic healing rates of 60.4% and 46.2%. In a 2022 active-comparator trial of 224 patients, eight-week endoscopic efficacy was 81.48% with polaprezinc and 74.31% with rebamipide, without significant superiority. A 2022 meta-analysis of three trials and 396 participants reported an odds ratio of 2.01 for eradication when polaprezinc was added to triple therapy, but certainty was very low.

02

Why this is classified as C (50)

Direct human ulcer trials and eradication-adjunct randomized trials prevent D, but older regional medicine data, active comparators, combination attribution, and very low certainty yield C with 50 points. Safety is reported separately.

Counterpoint. Pharmaceutical polaprezinc may provide short-term ulcer healing similar to other mucosal protective medicines in diagnosed disease. This does not establish a broad standalone supplement treatment for gastric and intestinal barriers.

Rejudgment record. New verdict — Accepted endoscopic ulcer trials and Helicobacter pylori adjunct trials but capped the grade at C because evidence centers on a medicine, active comparators, and concomitant treatment and cannot be attributed to a standalone supplement

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Endoscopic gastric-ulcer healing with pharmaceutical polaprezincCHuman trials exist, but evidence centers on older Japanese data and active comparators, with weak placebo-based standalone attribution.
Adjunctive effect of adding polaprezinc to Helicobacter pylori eradication therapyCA meta-analysis of three trials was positive, but certainty was very low and the effect belongs to combination treatment.
General gastric and intestinal barrier repair with standalone PepZin GI supplementationCBeyond small permeability studies, evidence is insufficient to extend pharmaceutical ulcer outcomes to broad supplement-based barrier repair.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Miyoshi A et al. 1992Multicenter randomized double-blind active-comparator trial258Japanese pharmaceutical-development context; detailed funding unknownSymptoms and endoscopic ulcer healingThe reported eight-week endoscopic healing rate was 60.4% with 150 mg/day and 46.2% with cetraxate.Key
Shen W et al. 2022Ten-center randomized double-blind double-dummy active-comparator trial224Chinese multicenter study; see paper for detailed disclosuresEight-week endoscopic efficacy and symptomsEfficacy was 81.48% with polaprezinc and 74.31% with rebamipide without significant superiority; symptoms were similar.Key
Abdelfatah AAS et al. 2022Systematic review and meta-analysis of adjunctive Helicobacter pylori trials396Reported no external fundingEradication and adverse eventsAdding polaprezinc yielded an intention-to-treat odds ratio of 2.01, but certainty was very low.Combination evidence
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Receipt — 4 References

All 4 cited sources were verified for existence at the original page (as of 2026-07-18).

Miyoshi A, Matsuo H, Miwa T, et al. Clinical evaluation of Z-103 (polaprezinc) on gastric ulcer: a multicenter double-blind comparative study with cetraxate hydrochloride [in Japanese]. Jpn Pharmacol Ther. 1992;20(1):199-223. No PMID or DOI identified.
checked
Shen W, Zhao X, Han Z, et al. Efficacy and safety of polaprezinc in the treatment of gastric ulcer: A multicenter, randomized, double-blind, double-dummy, positive-controlled clinical trial. Med Eng Phys. 2022;110:103860. PMID: 35999163. DOI: 10.1016/j.medengphy.2022.103860.
checked
Abdelfatah AAS, Farid AS, Al-Kuraishy HM, et al. Efficacy and Safety of Polaprezinc-Based Therapy versus the Standard Triple Therapy for Helicobacter pylori Eradication: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2022;14(19):4126. PMID: 36235778. PMCID: PMC9573391. DOI: 10.3390/nu14194126.
checked
Tan B, Luo HQ, Xu H, et al. Polaprezinc combined with clarithromycin-based triple therapy for Helicobacter pylori-associated gastritis: a prospective, multicenter, randomized clinical trial. PLoS One. 2017;12(4):e0175625. PMID: 28407007. PMCID: PMC5391070. DOI: 10.1371/journal.pone.0175625.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-18 · Corrections: none

Cite this verdict

Zinc L-carnosine x gastric-mucosal protection and ulcer healing Evidence Grade C card
[Chamgap] Zinc L-carnosine x gastric-mucosal protection and ulcer healing — Evidence Grade C·50. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/gut/zinc-l-carnosine-gastric-mucosa-ulcer-healing/ · CC BY 4.0

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

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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.