Melatonin and Omeprazole: what the published research says
PubMed indexes 8 records that name Melatonin and Omeprazole together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.
Every statement below is attributed to a named, dated, linked source.
This page lists published research relevant to Melatonin and Omeprazole. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.
A study appearing here is not proof that an interaction exists. Two substances can be named together in a paper that never tested them in combination, and a source listed as background may cover only one of them.
Findings are quoted from each abstract as the authors wrote them. NutriStack has not re-analysed, pooled, or reconciled them, and they may disagree with each other.
NutriStack’s own interaction assessment for this pair is not published here. It has not completed qualified-human clinical review, so it is withheld from search. See the publication gate.
Nothing here is medical advice. Decisions about prescription medication and supplements belong with your prescriber or pharmacist, who can see your full regimen.
The research
8 studies naming Melatonin and Omeprazole.
Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.
The Turkish journal of gastroenterology : the official journal of Turkish Society of Gastroenterology · 2023 · PMID 37768310
Randomized Controlled Trial78 participants
“The combination of sublingual melatonin (3 mg/day) with omeprazole (20 mg/day) may be more effective than omeprazole (20 mg/day) alone in the treatment of gastroesophageal reflux disease.”
“Plasma ghrelin levels did not change significantly after treatment with melatonin or Trp, while plasma leptin increased significantly in patients treated with melatonin or Trp but not with placebo. We conclude that melatonin or Trp, when added to omeprazole treatment, accelerates ulcer healing and this likely depends mainly upon the significant increments in plasma melatonin.”
Digestive diseases and sciences · 2005 · PMID 16110843
Comparative StudyAnimal study
“Intraperitoneal administration of alendronate did not cause much gastric irritation. Findings of the present study suggest that alendronate induces oxidative gastric damage by a local irritant effect and that melatonin and omeprazole are protective against this damage due to their antioxidant properties.”
Digestive diseases and sciences · 2001 · PMID 11281181
Comparative StudyAnimal study
“These findings suggest that active oxygene species and LPO have an important role in the pathogenesis of gastric mucosal damage induced by ASA and that both famotidine and omeprazole may be protective against this damage, although they were not as efficient as melatonin as an antioxidant. On the other hand, the antisecretory effect of omeprazole and famotidine may also be contributing to their antiulcer effect.”
“Moreover, in separate experiments, cotreatment of rats with melatonin and ranitidine or omeprazole was found to protect against stress ulceration in doses at which either of these alone could not protect the stomach. The findings raise the possibility of melatonin being considered as an effective gastroprotective agent individually or as a cotreatment with either ranitidine and omeprazole.”
Randomized Controlled TrialClinical Trial, Phase IIMulticenter StudyClinical Trial, Phase I
“Despite the fact that melatonin has a good safety profile, these findings raise concerns regarding the hepatotoxic potential of high doses of melatonin in polymedicated patients. This is attributed to a probable pharmacokinetic drug-drug interaction with concomitant medications sharing liver metabolization pathways with melatonin, leading to CYP450 metabolic pathways saturation.”
Names Melatonin and Omeprazole together in an interaction, co-administration, or pharmacokinetic context.
Names Melatonin and Omeprazole together in an interaction, co-administration, or pharmacokinetic context.
Limitations
What this evidence cannot tell you.
Search-based evidence indexes have real limits, and it is worth being explicit about them:
Selection. These records were found by searching PubMed titles and abstracts for both substance names alongside interaction and pharmacokinetic terms. Relevant work that phrases things differently, or is not indexed in PubMed, will be missing.
No effect size. The quoted conclusions are the authors’ words about their own study. We have not extracted effect direction or magnitude, and a single study’s conclusion is not a consensus.
Population mismatch. Findings in healthy volunteers, animals, or a specific patient group may not transfer to you, your dose, or your formulation.
Absence is not safety. Few published studies means the combination is under-studied, which is not the same as established as safe.
Nearby evidence
Other pairs with published research.
Pages covering Melatonin or Omeprazole alongside a different substance.
NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Melatonin, Omeprazole, and several hundred other substances.
The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.
NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.