Stomach lining repair supplements is a category built on four compounds: zinc carnosine, mastic gum, deglycyrrhizinated licorice and L-glutamine. They aren't interchangeable. Zinc carnosine has the most modern research behind it, usually dosed at 75 mg twice daily, while mastic gum rests on small trials that are now decades old. That gap decides what you can reasonably expect.
What the stomach lining research actually covers
The honest framing is comfort rather than repair. Studies on these ingredients measure symptom scores and marker changes over 4 to 8 weeks in people with ongoing stomach discomfort, and the endpoints are modest. Zinc carnosine has been studied at 75 mg twice daily for 8 weeks in small randomised trials, and the results point toward improved comfort and support for the mucosal layer. That's a real finding. It is also much narrower than the word repair implies.
Nobody has run a large trial showing these compounds rebuild tissue in healthy people who have no symptoms. The population studied almost always has something going on already, which is the same pattern you see across the mineral literature.
Four stomach lining repair supplements, four evidence bases
Zinc carnosine is a chelate of zinc and the dipeptide carnosine, and it is the best characterised of the four. Mastic gum, a resin from a Mediterranean shrub, shows up in trials from the 1990s with sample sizes in the dozens. DGL comes from licorice with the glycyrrhizin removed, and its studies are old and small. L-glutamine has a plausible mechanism, since it is a fuel source for intestinal cells, and relatively few controlled human trials behind it.
You'll often find products stacking all four at low doses. That usually means none of them reaches the amount used in research, which is a marketing decision rather than a clinical one. One compound at 75 mg beats four at 20 mg each.
Read the label for the word deglycyrrhizinated if licorice appears. Plain licorice root carries glycyrrhizin, which raises blood pressure in some people at higher intakes, and the DGL form exists precisely to avoid that.
What a sensible trial looks like
Pick one compound at a studied dose, run it for 8 weeks, and note what your stomach feels like after meals. Score it weekly on the same scale. If nothing shifts by week 8, stop and keep the money. If you were already eating a diet heavy in alcohol, late meals and painkillers, change that first, because no capsule outruns those inputs.
Zinc carnosine has a practical advantage. It delivers the mineral, which contributes to the normal function of the immune system and to normal cell division, so you're getting a nutrient with recognised roles alongside whatever the mucosal story adds. That also means it counts toward your daily intake, and the tolerable upper intake level for adults is 40 mg of elemental zinc per day, so check it against anything else in your stack.
Where the evidence runs thin
Here is the limit worth stating plainly. Most of these trials are small, several are old, and few have been replicated by independent groups. Systematic reviews on mastic gum and similar ingredients have repeatedly downgraded confidence over the years as better data arrived. The direction of travel has not been flattering.
Severe or persistent stomach pain, blood in stool, or unexplained weight loss are not supplement questions. Those need a clinician this week, not a capsule for 8 weeks.
Cost is the other honest factor. Many of these products run $1 or more per day, which is $365 a year for a speculative benefit. Ask whether that money buys you something you can measure, and if you can't name the measure, you probably won't notice the difference either way.
Buy one studied compound at a real dose, give it 8 weeks, and judge it on your own notes.
Frequently asked questions
Which compounds are studied here?Show answerHide answer
Zinc carnosine, mastic gum, DGL and L-glutamine, each with different bodies of work.
Is it strong evidence?Show answerHide answer
For zinc carnosine, moderately. For mastic gum, small and old trials.
What should I expect from it?Show answerHide answer
Support for normal stomach comfort, judged over weeks rather than days.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
