This page lists 2 published records selected during NutriStack’s source review for Diltiazem and L-Theanine. PubMed’s index holds too little research naming both together to build a page from, so these are the sources a reviewer relied on, and some of them study one member of the pair rather than the combination. Each entry says which. The key findings come first, in the authors’ own words, followed by every study with its design and PubMed link.
A summary of published research, not medical advice. A pharmacist can check any combination against your full list of medicines and supplements.
Reviews and human studies first. Each quote is the authors’ own conclusion about their study, not a NutriStack assessment, and a single study is not a consensus.
“The findings above denote that L-theanine not only reduces anxiety but also attenuates the blood-pressure increase in high-stress-response adults.”
The research
2 studies naming Diltiazem and L-Theanine.
Hand-reviewed sources first, then papers naming both substances in the title, then human trials and systematic reviews.
Journal of physiological anthropology · 2012 · PMID 23107346
Randomized Controlled Trial
“The findings above denote that L-theanine not only reduces anxiety but also attenuates the blood-pressure increase in high-stress-response adults.”
Selected by hand during source review for Diltiazem and L-Theanine, rather than by the automated PubMed query. It covers one side of the pair; it is listed as background the reviewer relied on, not as a study of the combination.
The Journal of the Louisiana State Medical Society : official organ of the Louisiana State Medical Society · 2004 · PMID 15688675
Case ReportsHuman subjects
Selected by hand during source review for Diltiazem and L-Theanine, rather than by the automated PubMed query. It covers one side of the pair; it is listed as background the reviewer relied on, not as a study of the combination.
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.
How to read this page
A literature summary, not guidance.
A study listed here is not proof that Diltiazem and L-Theanine interact. 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.
Decisions about prescription medication and supplements belong with your prescriber or pharmacist, who can see your full regimen. Our timing guide and forms guide explain the general mechanisms.
Nearby evidence
Other pairs with published research.
Pages covering Diltiazem or L-Theanine 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 Diltiazem, L-Theanine, and several hundred other substances.
Log your routine, get reminders at the times you choose, and scan a label to add a product. The checker is a research and organisation tool, not a clinical decision aid.
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.
