# Polaprezinc (zinc L-carnosine)

Japanese ulcer drug sold as a supplement; the go-to oral 'stomach lining' option for gastritis.

- Page: https://peprank.xyz/peptides/polaprezinc
- Category: Gut (Supplement)
- Also known as: zinc carnosine; Promac (Japan); PepZin GI; Zinlori / PepticCare / Gastric Soothe
- Routes: Oral
- Sequence: AH (β-alanine, not L-alanine; zinc L-carnosine chelate)
- Safety tier: Strict: Avoid · Balanced: Avoid · Evidence only: Avoid
- Risk axes (0 none to 3 severe): Seen harm 2, Mechanism 3, Data gap 0, Silent harm 2, Product 0
- Positive: 54% of 25 graded reports glowing or positive, shrunk toward the 49% all-report average by 8 reports' weight
- Rank: #23 of 23 supplements
- Graded reports: 25 (Glowing 7, Positive 7, Mixed 2, Nothing 1, Negative 3, Bad reaction 5)
- Evidence: Approved drug — in Japan (Promac, 1994) for gastric ulcer; RCTs and a meta-analysis as an add-on to H. pylori triple therapy; small human gut-permeability trials
- Access: Supplement
- Onset: Days to 2 weeks for pain relief in responders; 1-2 months for healing; GI reactions appear within an hour of a dose.
- Lasts: Taken twice daily; the Japanese label course for ulcer is 8 weeks.
- Cost per month: ≈ €32 (at 150 mg/day, Supersmart at €7.11/g)
- Updated: 2026-10-30

## What users report

Sharply split. Gastritis and GERD subs hold many 'it cured me' posts, with pain relief in days to two weeks and healing over 1-2 months; several users keep a bottle in the cupboard and take it at the first twinge of a flare. A large minority, about a third of reports, have the opposite experience: burning, intestinal cramps, nausea or vomiting within an hour, sometimes a multi-day flare, mostly when taken on an empty stomach as the bottle says. Taking it with food fixes the nausea for many. Most positive users also ran a PPI, diet changes or a supplement stack. Felt nothing: ~10-15% of reports; in the big threads more say 'didn't work' than the sampled reports show.

**Effects:** less gastritis pain and burning; less fullness, bloating and belching; faster healing alongside a PPI or after H. pylori treatment; flare control taken as needed; better stools for some SIBO/IBS users

**Downsides:** nausea or vomiting on an empty stomach (zinc); burning or intestinal cramps within an hour in a sizeable minority; occasional multi-day flare; metallic taste; constipation

**Risks:** copper deficiency from the zinc (34 mg elemental zinc at 150 mg/day): anaemia, neutropenia and potentially lasting neuropathy; Japan added it to the Promac label as a clinically significant adverse reaction in 2016 after 9 reported cases

**Caveat:** Kept as mostly-clean rather than excluded: its one harm path, copper deficiency, is the ordinary zinc-copper antagonism, dose- and time-dependent, absent from 8-week courses at the labelled 150 mg/day (below the 40 mg zinc upper limit) in the trials, and the Japanese cases clustered in off-label long-term use, dialysis and tube feeding. It becomes a real risk on open-ended daily use or stacked with other zinc. Carnosine itself has no known harm. The many GI reactions on Reddit are unpleasant but self-limiting, and mostly come from taking it on an empty stomach.

**Typical use:** 75 mg (16-17 mg zinc) twice daily for up to 8 weeks; take with or after food if it causes nausea; do not stack with other zinc; add 1-2 mg copper on longer courses.

**Getting it:** Prescription drug in Japan and Korea; an over-the-counter supplement in the US, UK and EU (PepZin GI and many own-brand zinc carnosine capsules).

**Stacked with:** PPI or H2 blocker (most positive reports ran it alongside acid suppression; the H. pylori trials used it with triple therapy); copper (1-2 mg/day) (users on long courses add a little copper to offset zinc-induced copper depletion); bovine colostrum (combined in the Davison 2016 exercise gut-permeability trial); DGL licorice / slippery elm (common gastritis stack, which makes individual credit hard to assign)

## Risk profile

- **Seen harm 2/3:** A label warning: Japan added copper deficiency as a clinically significant adverse reaction in 2016 after nine cases, some with pancytopenia needing transfusion, and published cases include severe leukopenia after four months at the standard 150 mg/day. Mostly long-term, off-label or dialysis use, and preventable by limiting duration or checking copper.
- **Mechanism 3/3:** Zinc-induced copper deficiency is an established pathway in humans, shown with this drug: 150 mg/day supplies 34 mg of zinc, above the EU's 25 mg upper limit, and can cause anaemia, neutropenia and, with other zinc sources, lasting myelopathy.
- **Data gap 0/3:** Approved in Japan since 1994, with RCTs and meta-analyses as an ulcer and H. pylori add-on; EFSA did not establish its safety as an EU novel food, for particle-size reasons rather than a harm.
- **Silent harm 2/3:** Copper deficiency builds silently over months and shows on a blood count and copper level before the neurological damage, which may not reverse.
- **Product 0/3:** A pharmacy drug in Japan and Korea and an OTC supplement (PepZin GI and others) taken orally elsewhere.
- **Never if:** Daily use beyond about 8 weeks without copper monitoring; Combination with other zinc supplements; Dialysis, tube feeding or malnutrition (higher copper-deficiency risk)

## Top reports

- Glowing, gut, one capsule a day after breakfast: “Then I gave zinc carnosine a shot for one month once a day after breakfast. To my pleasant surprise, it cured all my symptoms: appetite returned, stomach pain went away, and nausea/clenching disappeared. As always, YMMV.” — [r/Gastritis](https://www.reddit.com/r/Gastritis/comments/11jjugt/zinc_carnosine_did_the_job/)
- Glowing, gut, Metagenics Zinlori with food: “Yes, it cured mine. I take it for about a week and the effects last a few months. I take it with food. Taking it on an empty stomach has always made me vomit within an hour or two.” — [r/Gastritis](https://www.reddit.com/r/Gastritis/comments/wnydf4/does_zinc_carnosine_really_help_with_gastritis/ik8b6l4/)
- Glowing, gut, first thing in the morning: “It's worked great for me too! I've taken it for 3 months now first thing in the morning and feel almost healed!” — [r/Gastritis](https://www.reddit.com/r/Gastritis/comments/n52n4i/zinc_carnosine_cured_me/gx094wf/)
- Glowing, gut, PepZin GI: “I had that too for 6 weeks. Started taking PepZInGI (same thing) on Tuesday and felt better almost immediately. I was eating bar food and drinking beers this weekend.” — [r/Gastritis](https://www.reddit.com/r/Gastritis/comments/11jjugt/zinc_carnosine_did_the_job/jb3d1rb/)
- Glowing, gut, 2 capsules PepZin GI per flare, 2-3 doses: “It has repeatedly saved me from debilitating gastritis flare up’s. I initially took the nature’s bounty bottle and it already showed significant results but later switched to the cheaper but bigger dosage bottles by doctors best pepzin GI. It’s truly a miracle drug for me.” — [r/Gastritis](https://www.reddit.com/r/Gastritis/comments/wnydf4/does_zinc_carnosine_really_help_with_gastritis/jevsy11/)

## Cheapest in Europe

- [Supersmart](https://www.supersmart.com/fr/boutique/digestion/zinc-l-carnosine-complement-anti-reflux-0401) (LU): Zinc L-Carnosine 37.5 mg, 120 veg capsules, €32, €7.11/g

## Studies

- [Tan et al., Polaprezinc combined with clarithromycin-based triple therapy for H. pylori-associated gastritis: multicenter RCT (PLOS One 2017)](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0175625) (rct, n=303, 2017): Adding 75 mg polaprezinc twice daily raised H. pylori eradication from 58.6% to 77.0% (ITT); doubling the dose added nothing but more adverse events; no serious adverse events.
- [Mahmoud et al., Polaprezinc-based therapy vs standard triple therapy for H. pylori: systematic review and meta-analysis (Nutrients 2022)](https://www.mdpi.com/2072-6643/14/19/4126) (meta-analysis, n=396, 2022): Three RCTs; polaprezinc add-on roughly doubled the odds of eradication (ITT OR 2.01) with no difference in total adverse events.
- [Mahmood et al., Zinc carnosine stabilises small bowel integrity and stimulates gut repair processes (Gut 2007)](https://pmc.ncbi.nlm.nih.gov/articles/PMC1856764/) (controlled, n=10, 2007): Crossover in healthy volunteers: 5 days of indomethacin tripled gut permeability on placebo, with no significant rise when 37.5 mg zinc carnosine was taken twice daily.
- [Davison et al., Zinc carnosine works with bovine colostrum in truncating exercise-induced gut permeability (AJCN 2016)](https://pubmed.ncbi.nlm.nih.gov/27357095/) (rct, n=8, 2016): Four-arm crossover: 14 days of zinc carnosine or colostrum each cut the threefold exercise-induced rise in gut permeability by about 70%; the combination worked sooner.

## Sources

- [PMDA (Japan), Revision of precautions: polaprezinc and copper deficiency (Nov 2016)](https://www.pmda.go.jp/files/000219558.pdf)
- [PMDA, Summary of investigation results: polaprezinc, 9 copper-deficiency cases (Nov 2016)](https://www.pmda.go.jp/files/000215039.pdf)
- [Kadoya et al., Copper deficiency-induced pancytopenia in a haemodialysis outpatient treated with polaprezinc (Ther Apher Dial 2016)](https://doi.org/10.1111/1744-9987.12398)
- [Hewlings & Kalman, A review of zinc-L-carnosine and its effects on oral mucositis, taste disorders and GI disorders (Nutrients 2020)](https://www.mdpi.com/2072-6643/12/3/665)