PepRank

Polaprezinc (zinc L-carnosine)

54%positive25 reports

Also: zinc carnosine · Promac (Japan) · PepZin GI · Zinlori / PepticCare / Gastric Soothe

ExcludedSupplementOral

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

AH · β-alanine, not L-alanine; zinc L-carnosine chelate (2 residues)

AH β-alanine, not L-alanine; zinc L-carnosine chelate

#23 of 23 supplements · updated
Access
Supplement
Cost / month
≈ €32
at 150 mg/day · Supersmart · €7.11/g
OralFelt in 2 days – 2 weeks

Builds over days or weeks of regular use rather than with each dose.

25 user reports
Glowing 7Positive 7Mixed 2Nothing 1Negative 3Bad reaction 5

  • r/Gastritis· · 90 upvotesOriginal ↗

    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.

    Glowingone capsule a day after breakfast · Oral · 1 month

    gastritis after harsh herbal antimicrobials and coffee on an empty stomach; H. pylori negative; Source Naturals Gastric Soothe

  • r/Gastritis· · 15 upvotesOriginal ↗

    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.

    GlowingMetagenics Zinlori with food · Oral · about a week per course

    gastritis, previously on PPIs

  • r/Gastritis· · 73 upvotesOriginal ↗

    Not sure what happened as I've heard zinc carnosine is legit, but I took this for about a week and it essentially destroyed my stomach which had been getting better for the past 4 months. Now going through a major flare (no other changes in lifestyle).

    Bad reaction8 mg zinc per pill, 1-2 a day · Oral · 1 week

    gastritis that had been improving for 4 months

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.
Best 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
Watch
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
Evidence
Approved drug — approved 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
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

User reports 25

  • r/Gastritis· · 90 upvotesOriginal ↗

    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.

    Glowingone capsule a day after breakfast · Oral · 1 month

    gastritis after harsh herbal antimicrobials and coffee on an empty stomach; H. pylori negative; Source Naturals Gastric Soothe

  • r/Gastritis· · 15 upvotesOriginal ↗

    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.

    GlowingMetagenics Zinlori with food · Oral · about a week per course

    gastritis, previously on PPIs

  • r/Gastritis· · 11 upvotesOriginal ↗

    It's worked great for me too! I've taken it for 3 months now first thing in the morning and feel almost healed!

    Glowingfirst thing in the morning · Oral · 3 months

    chronic gastritis

  • r/Gastritis· · 8 upvotesOriginal ↗

    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.

    GlowingPepZin GI · Oral · under a week at time of writing

    six weeks of gastritis symptoms

  • r/Gastritis· · 7 upvotesOriginal ↗

    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.

    Glowing2 capsules PepZin GI per flare, 2-3 doses · Oral · as needed for flares

    recurrent gastritis triggered by empty stomach or spicy food

  • r/Gastritis· · 6 upvotesOriginal ↗

    I’ve been taking nexium for weeks and it helps but still plenty of discomfort. Started taking 2 PepZincGI 2x a day. So far a lifesaver. Feel 100% again.

    Glowing2 PepZin GI twice a day · Oral

    suspected H. pylori; on Nexium for weeks with residual discomfort, so the PPI shares the credit

  • r/Gastritis· · 1 upvotesOriginal ↗

    I am going through the same experience!! I feel pretty much healed. I wish I started the zinc sooner. It’s been a little over a month and I almost feel normal and can almost eat anything again!

    GlowingOral · a little over a month

    gastritis

  • r/SIBO· · 35 upvotesOriginal ↗

    I've been taking it for almost a week now and feel better than ever. Had normal BM's today, energy levels are way up. Someone else posted about it too and so far its been the most noticeable supplement I've tried to date.

    PositiveDoctor's Best PepZin GI, 2 capsules a day on an empty stomach · Oral · under a week

    SIBO/IBS for ~3 years; only a week in at time of writing

  • r/Gastritis· · 27 upvotesOriginal ↗

    I couldn't improve my symptoms, which were epigastric pressure, a feeling of fullness, and sometimes nausea, until I started treatment with zinc carnosine. After starting to take zinc carnosine, my symptoms improved significantly, and so did my quality of life.

    Positive75 mg on an empty stomach in the morning + 75 mg two hours after dinner · Oral · 2+ months

    M34, atrophic gastritis after eradicated H. pylori; diet changes alone had not helped

  • r/Gastritis· · 15 upvotesOriginal ↗

    i know that zinc carnosine doesn't work for everyone but i wanted to share that it has tremendously sped up my healing process. i've been taking it for roughly 3 weeks and i feel almost back to normal. before, i was just taking PPI and still felt horrible.

    Positivetwice a day, with 1.5 mg copper glycinate · Oral · 3 weeks

    gastritis; stacked with slippery elm, marshmallow, DGL, glutamine and enzymes, so not isolated

  • r/Gastritis· · 5 upvotesOriginal ↗

    After 3 weeks of daily use, I'm noticing improvement, particularly relief from that burning pain. I'm also taking 20 mg. daily of a PPI. I'm trying to attack from all angles.

    Positiveon an empty stomach in the morning · Oral · 3 weeks

    gastritis for years; with 20 mg/day PPI

  • r/Gastritis· · 3 upvotesOriginal ↗

    Chiming in to tell you guys that Zinc Carnosine worked very well for me. I've struggled with gastritis for 5 years now. I noticed pain relief in about 2 weeks.

    PositiveDoctor's Best PepZin GI, 2 x 75 mg on an empty stomach in the morning · Oral · about 2 months

    gastritis for 5 years; never took the prescribed PPI

  • r/Gastritis· · 2 upvotesOriginal ↗

    It was about 2 months when symptoms started to subside. About 6 months to completely heal confirmed from an endoscopy. I did have to control my diet too which made a big difference so it wasn't all from the zinc carnosine but for sure helped.

    PositiveDoctor's Best, emptied into DGL powder on an empty stomach · Oral · about 6 months

    gastritis; strict diet and Gaviscon alongside

  • r/GERD· · 1 upvotesOriginal ↗

    I’ve taken zinc L-carnosine for years and I feel like it works. You have to take it consistently, I did for about 6 to 8 months (pure encapsulations brand/ peptic care) it’s pricey so it will be an investment.

    PositivePure Encapsulations PepticCare · Oral · 6-8 months consistently

    GERD; modified diet alongside

  • r/Gastritis· · 15 upvotesOriginal ↗

    The carnosine bit irritated my stomach but I felt much better so I got zinc-glycinate instead. I felt better without the irritation.

    MixedOral

    gastritis; credits the zinc rather than the carnosine

  • r/Gastritis· · 3 upvotesOriginal ↗

    I had a really bad spell for three months, started the Zinc Carnosine and immediately started feeling better. Was better about a month later. But I've been on my current bout for almost a year, and have been on the stuff the whole time. Nothing.

    MixedOral · about a year

    recurrent gastritis

  • r/Gastritis· · 7 upvotesOriginal ↗

    It didn't work for me but I think I took it for 1-2 months before I ran out and chose not to repurchase since it wasnt helping.

    NothingOral · 1-2 months

    gastritis

  • r/Gastritis· · 5 upvotesOriginal ↗

    It's horrible! I took it 3 times with food on separate occasions and 2 different brands and it BURNS so badly.

    NegativeOral · 3 doses, 2 brands

    gastritis

  • r/Gastritis· · 3 upvotesOriginal ↗

    I tried the one from pure and it didn't work. It caused me more pain and I tasted a metallic taste in my mouth.

    NegativeOral

    gastritis; Pure Encapsulations product

  • r/Gastritis· · 1 upvotesOriginal ↗

    I was so hopeful when I took it, but it gave me terrible nausea and I stopped after 1 day.

    NegativeOral · 1 day

    gastritis

  • r/Gastritis· · 73 upvotesOriginal ↗

    Not sure what happened as I've heard zinc carnosine is legit, but I took this for about a week and it essentially destroyed my stomach which had been getting better for the past 4 months. Now going through a major flare (no other changes in lifestyle).

    Bad reaction8 mg zinc per pill, 1-2 a day · Oral · 1 week

    gastritis that had been improving for 4 months

  • r/Supplements· · 12 upvotesOriginal ↗

    I took a pill last night on the empty stomach and an hour later terrible intestinal cramps started . Terrible kind . Feels like my intestines are being squeezed and feels like diarrhea is coming but it doesn't actually come .

    Bad reaction3 tablets over 24 hours on an empty stomach · Oral · 1 day

    stress- and caffeine-related gastritis

  • r/Gastritis· · 10 upvotesOriginal ↗

    Only took it for 3 days, on the 3rd day (yesterday) I had horrible painful bowel cramps and nausea. Was feeling ok afterwards but today I am feeling super nauseous when my stomach is empty, even though I didn't take any.

    Bad reactionPepZin GI · Oral · 3 days

    reflux/gastritis that had settled for a week

  • r/GERD· · 6 upvotesOriginal ↗

    It gave me the worst flare up I've ever experienced in my life. I just threw out my bottle. It sucks because I was improving and thought I could 'top off' my healing with it but it just set me back immensely.

    Bad reactionPepZin GI · Oral

    GERD that was improving; added as a "top-off"

  • r/Gastritis· · 2 upvotesOriginal ↗

    My stomach did somersaults an hour after I took Zinc carnosine. It briefly took away all the pain and then after an hour passed I had the worst spasms. I took it as directed and only did it once, never again.

    Bad reactionOral · one dose

    gastritis

Safety

Tier by safety barStrict ExcludedBalanced ExcludedEvidence only Excluded

Seen harmMechanismData gapSilent harmProduct

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. PMDA 2016: revision of precautions, copper deficiency added as a clinically significant adverse reaction ↗PMDA 2016: polaprezinc and copper deficiency, 9 cases (summary of investigation) ↗Severe leukopenia from copper deficiency after 4 months of 150 mg polaprezinc (PubMed 35900669) ↗Copper-deficiency cytopenias: 5 of 15 patients on polaprezinc (PubMed 35845195) ↗
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. PMDA 2016: polaprezinc and copper deficiency, 9 cases (summary of investigation) ↗Severe leukopenia from copper deficiency after 4 months of 150 mg polaprezinc (PubMed 35900669) ↗
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. Recent advances on polaprezinc for medical use (approved in Japan 1994) ↗Tan et al. 2017: polaprezinc with triple therapy for H. pylori, RCT n=303 (PLOS One) ↗EFSA 2022: safety of zinc L-carnosine as a novel food not established ↗
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. PMDA 2016: polaprezinc and copper deficiency, 9 cases (summary of investigation) ↗
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)

Where to buy 1 in Europe · 3 total

ShopFormPricePer mgTesting
iHerbUScapsules · 4500 mg€24€5.33/gNo public tests
SupersmartEU · LUcapsules · 4500 mg€32€7.11/gOwn COA
iHerbUScapsules · 4500 mg€37€8.13/gNo public tests

Studies 4

Sources 4

More in Gut all 6 →

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  3. 3Bovine colostrum CautionSupplement Oral≈ €28–56 / month47%positive24 reportsCow's first milk: immunoglobulins, lactoferrin and growth-factor peptides for gut lining and fewer colds.
  4. 4Plecanatide Excluded Oral≈ €540–650 / month45%positive25 reportsApproved uroguanylin-like GC-C agonist tablet for constipation and IBS-C; linaclotide's sibling.The label warns of severe diarrhoea (0.6-1% in trials, most within the first days) with instructions to stop and rehydrate, and Reddit users describe days of watery diarrhoea leaving them badly dehydrated. Its sibling linaclotide has post-marketing hospitalisations for the same harm. It is obvious and stops when the drug does, so under a doctor it is a reasonable constipation treatment, but it is a real route to serious harm and does not belong on a clean wellness list.
  5. 5Linaclotide Excluded Oral≈ €450 / month45%positive25 reportsApproved gut-only GC-C agonist pill for IBS-C and constipation; works for many, often too well.The label warns of severe diarrhoea (2% in trials), and post-marketing reports describe dehydration with fainting, low blood pressure and low potassium or sodium that needed IV fluids or hospital, plus rare anaphylaxis and angioedema. The harm is obvious at once and stops when the drug does, so under a doctor it is a reasonable IBS-C treatment, but it is a real route to serious harm and does not belong on a clean wellness list.

Sequence beads

Each bead is one amino acid in the peptide's chain, coloured by its side chain: grey for non-polar, cyan for polar, blue for positively charged and fuchsia for negatively charged. Length and mix tell related peptides apart at a glance, from a two-residue dipeptide like carnosine to a 43-residue protein like thymosin beta-4. The colours describe chemistry only and predict neither effect nor safety.

non-polarpolarpositivenegative

Report grades

Every first-hand Reddit or X report is graded on its own, from glowing through positive, mixed, nothing and negative to bad reaction, and the bar shows how those grades split. Posts that look vendor-adjacent stay on the peptide's page but are left out of the counts.

GlowingPositiveMixedNothingNegativeBad reaction

% positive

The share of a peptide's graded Reddit and X reports that are glowing or positive, vendor-adjacent posts left out. A peptide with few reports is pulled toward the average of all reports, as if it had eight average ones besides its own, so two glowing posts cannot top the list. Kept peptides rank by the same reports' mean grade, shrunk the same way, and excluded ones follow in that order.

Researcher estimate

No first-hand report of this peptide has been graded yet, so the figure is the researchers' own rating out of 10 from what they read about it. It ranks alongside the computed scores until reports arrive.

Safety tier

Each peptide is tiered clean, caution or excluded from its five risk axes under the chosen safety bar. An excluded peptide has a plausible route to serious harm, so it stays listed with the reason but ranks behind every other entry, however good its reviews.

Safety bar

The safety bar sets how much risk it takes to exclude a peptide. Strict: out on any serious mechanism with little human data, or any documented serious harm. Balanced: out on documented serious harm (unless it is obvious, reversible and from a regulated product), or a serious mechanism whose harm would be silent with no human data at all. Evidence only: out only on documented serious harm in humans that is lasting, delayed or from grey-market product.

Seen harm

Documented serious adverse events in humans, from 0 for none despite real exposure to 3 for deaths or several well-documented serious harms. Serious means a hospital or emergency visit or harm lasting weeks, so a headache or a bad night does not count.

Mechanism

A plausible biological route to serious harm at the doses people use, such as growth-factor signalling, hormone-axis suppression, heart or blood-pressure effects or immune activation. It runs from 0 when none is known to 3 when a dangerous pathway has been shown in living animals.

Data gap

How little human safety data exists for the molecule actually sold, from 0 for an approved drug with large trials and years of use to 3 for no human safety data at all. A modified analogue does not inherit its parent's trials.

Silent harm

Whether the feared harm would show quickly or stay hidden, from 0 when it is obvious and goes on stopping to 3 when it is silent and delayed, like tumour promotion or slow organ damage. User reports cannot reveal a harm that takes years to appear, so a high score here limits what good reviews can tell you.

Product

The risk of what people actually buy, from 0 for a regulated pharmacy or supplement product taken by mouth or on the skin to 3 for a grey-market injectable. In one dataset of 6,441 grey-market samples, 42–71% failed basic quality criteria and 15% carried endotoxin.

Evidence

The strongest kind of study behind the peptide's effects, from an approved drug through human controlled trials and small human studies to animal work or nothing of its own. Animal results often fail to carry over to people.

Access

How people get it: as an approved drug, a compounded prescription, an over-the-counter supplement or from the grey market, where nobody checks the vial. The channel decides both the legal position and the risk of a bad batch.

Price per month

Thirty days of the typical dose, from its low end to its high end, priced at the listing a careful buyer would choose: in stock, from a shop scoring 4 of 5 on trust (third-party tested where no score is set), failing that 3, a pure pack before a blend, a European shop first, then the cheapest per mg. The range is the dose's, not the shops'. A per-dose amount counts once a day unless the dose says otherwise. Prices are in euros at ECB rates of 2026-10-29, before shipping; the shop table keeps each listing's price per mg, per gram for bulk supplements. Where no listing can be priced the researchers' own estimate stands in, and says so.

Dose users report

The middle half of the daily doses stated in at least five first-hand reports, vendor posts left out. Where its middle sits more than twice above or below the declared dose, the month is priced at it as well, since what people take is what they pay for.

Testing

Whether the shop publishes lab results: third-party tested means an independent lab checks each batch, own COA means the shop's own certificate of analysis, and no public tests means neither. A certificate shows purity, not safety.

Added peptide

Some packs sold under one peptide's name hold a second one, such as 5 mg GHK-Cu in a nasal kit, stated only in the description. Sprayed in the nose or injected it reaches the blood like an injection, so it carries the risk of that route and is tiered as the injectable form, whatever its tier on the skin. A pack whose page gives no contents list may hold more than its name.