Glycine + Metoprolol
Metoprolol brand names: Lopressor, Toprol XL.
We found no known interaction between Glycine and Metoprolol in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Metoprolol states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.
Glycine and Metoprolol
We checked these two against our interaction database. Here is what we found.
No Known Interaction Found
We did not find a documented interaction between Metoprolol and Glycine in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.
If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.
Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.
Glycine safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Why No Interaction Is Listed for Metoprolol
Interactions in our licensed database are recorded against drug classes, not just single drug names. Metoprolol is filed under 6 classifications — including beta-blockers, antihypertensive drugs, cytochrome p450 2d6 (cyp2d6) substrates. Glycine has documented interactions with 1 drug class — the most serious being clozapine (clozaril) (moderate) — and none of Metoprolol’s classifications are among them.
Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.
Glycine Does Interact With Other Medications
Glycine has 1 moderate known drug interaction in our database — Metoprolol isn’t one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Glycine
We haven’t checked that one against Glycine yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Glycine. Pick one to open its full report.
Some Metoprolol Products Have a Food Rule — Glycine Should Not Break It
At least one FDA label for a product containing Metoprolol says to take it with food. If you take Glycine on an empty stomach out of habit, keep them separate — and take Metoprolol with a meal where the label says to.
This may not be true of your version. Food instructions belong to the product, not the ingredient: two Metoprolol products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.
Administer once daily with food or after a meal.
From the Dosage and Administration section of the FDA label we read for Metoprolol — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›
A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.
What Metoprolol Is Prescribed For, and What Glycine Has Been Studied For
These two come up together because they touch the same health topic — not because they do the same job. Metoprolol is a prescription medicine with approved uses on its FDA label. Glycine is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.
Metoprolol is prescribed for: Metoprolol is used to treat several heart and blood pressure conditions. Metoprolol succinate extended-release tablets (including Toprol-XL) are approved for high blood pressure, angina pectoris (chest pain from the heart), and heart failure. Metoprolol tartrate tablets (including Lopressor) are approved for high blood pressure, angina, and — when used alongside intravenous metoprolol — to reduce the risk of cardiovascular death after a definite or suspected heart attack. Metoprolol tartrate injection (intravenous form) is used in hemodynamically stable patients with a definite or suspected acute heart attack to reduce cardiovascular death, and is followed by oral metoprolol therapy.
Read the rest of what Metoprolol is prescribed for
Lowering blood pressure with metoprolol reduces the risk of strokes and heart attacks.
Glycine has been studied for:
-
Stroke studied, not established Glycine has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows
Glycine for stroke
It is unclear if sublingual glycine is beneficial in patients with acute ischemic stroke.
Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Metoprolol on your own; if you are taking Glycine for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.
Questions About Glycine or Metoprolol
These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Glycine or Metoprolol, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:
- Can You Take Benadryl With L-Theanine, Glycine And Inositol? ›
- Does MCT Oil Interact With Amlodipine or Metoprolol? ›
- Concerns Taking Metoprolol With Saw Palmetto ›
- Concerns With Taking Both Metoprolol and Propafenone ›
Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.
See Every Supplement That Interacts With Metoprolol
This page covers Glycine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metoprolol page lists 183 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Indian Snakeroot (major) and Tyramine (major).
By severity: 5 major · 152 moderate · 26 minor.
From our pharmacist’s overview on the Metoprolol page
“With metoprolol (Lopressor, Toprol XL), a beta-blocker for high blood pressure and heart problems, these interactions deserve genuine care, starting with the five rated major. Most entries pull blood pressure one way or the other: many supplements add to metoprolol's lowering effect and can drop pressure too far, while a few, tyramine…”
Reviewed by 2 · Jul 18, 2026
Taking Glycine as Part of a Dietary Supplement Product? Check It for Interactions
We hold 3,022 real supplement products containing Glycine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Glycine. Even though Glycine itself has no known interaction with Metoprolol, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:
Where Glycine and Metoprolol Sit Against Everything Else
Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.
#65 of 1,452 supplements looked up here in the last 7 days
#7 of 2,830 medications looked up here in the last 7 days
Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.
Where does our data come from?
- Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
- Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Glycine reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Glycine and Metoprolol records this page draws on were last updated July 10, 2026.
- What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
About Glycine
What is Glycine?
- Sleep quality and insomnia
- Relaxation
- Cognitive function
- Metabolic health
- General wellness
Glycine is a non-essential amino acid your body makes on its own and that also appears in protein-rich foods. It is most studied for improving sleep quality, where early research is promising but limited, and it appears generally well tolerated at common doses. Talk with your pharmacist or doctor before starting it, especially if you take other medicines or have a health condition.
Amino acid (made synthetically or by the body) · Powder, capsules, tablets
An interaction check asks whether these two react with each other — it does not ask whether Glycine is a good idea for someone in your situation. Here is what our Glycine record says about it on its own.
Glycine: dosing
There is no official standardized dose of glycine for any health condition. In sleep studies, a few grams taken before bedtime have been used, but the best dose for an individual is not established.The safest approach is to follow the directions on the product label and start with the lowest amount.
From our Glycine monograph — the full record covers uses, side effects and every documented interaction.
About Metoprolol
What Is Metoprolol Used For?
Brand names: Lopressor, Toprol XL
Metoprolol is used to treat several heart and blood pressure conditions. Metoprolol succinate extended-release tablets (including Toprol-XL) are approved for high blood pressure, angina pectoris (chest pain from the heart), and heart failure. Metoprolol tartrate tablets (including Lopressor) are approved for high blood pressure, angina, and — when used alongside intravenous metoprolol — to reduce the risk of cardiovascular death after a definite or suspected heart attack.
Metoprolol tartrate injection (intravenous form) is used in hemodynamically stable patients with a definite or suspected acute heart attack to reduce cardiovascular death, and is followed by oral metoprolol therapy. Lowering blood pressure with metoprolol reduces the risk of strokes and heart attacks.
Most-Reported Side Effects for Metoprolol
From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
Other Drugs & Glycine
Browse every other medication we’ve checked against Glycine — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
1 interaction
No interaction 2,828 drugs checked — show the list
We also checked Glycine against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Testosterone ›
- Losartan Potassium ›
- Aspirin ›
- Ivermectin ›
- Rivaroxaban ›
- Rosuvastatin ›
- Escitalopram ›
- Tadalafil ›
- Acetaminophen ›
- Clopidogrel ›
- Valacyclovir ›
- Atorvastatin ›
- Docusate ›
- Hydroxyurea ›
- Abemaciclib ›
- Methamphetamine ›
- Sumatriptan ›
- Ibuprofen ›
- Semaglutide ›
- Tirzepatide ›
- Warfarin Sodium ›
- Prednisone ›
- Propranolol ›
- Lisdexamfetamine ›
- Acyclovir ›
- Bupropion ›
- Metformin ›
- Amoxicillin ›
- Lisinopril ›
- Bendamustine ›
- Amitriptyline ›
- Doxycycline ›
- Lamotrigine ›
- Fluoxetine ›
- Methotrexate ›
- Acetaminophen, Codeine ›
- Gabapentin ›
- Amphetamine ›
- Pregabalin ›
- Isotretinoin ›
- Dextroamphetamine ›
- Azithromycin ›
- Clonazepam ›
- Quetiapine ›
- Omeprazole ›
- Amlodipine Besylate ›
- Methylene Blue ›
- Duloxetine ›
- Letrozole ›
- Buspirone ›
- Citalopram ›
- Ciprofloxacin ›
- Naproxen ›
- Bisoprolol ›
Showing the 60 most looked-up of 2,828 medications checked with no known interaction — see the full Glycine list.
Glycine References
The 5 references that drive our Glycine monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.
- Heresco-Levy U, Javitt DC, Ermilov M, et al. Efficacy of high-dose glycine in the treatment of enduring negative symptoms of schizophrenia. Arch Gen Psychiatry 1999;56:29-36.. PubMed
- Potkin SG, Jin Y, Bunney BG, Costa J, Gulasekaram B. Effect of clozapine and adjunctive high-dose glycine in treatment-resistant schizophrenia. Am J Psychiatry 1999;156:145-7.. PubMed
- Gusev EI, Skvortsova VI, Dambinova SA, et al. Neuroprotective effects of glycine for therapy of acute ischaemic stroke. Cerebrovasc Dis 2000;10:49-60. PubMed
- Inagawa K, Kawai N, Ono K, Sukegawa E, Tsubuku S, Takahashi M. Assessment of acute adverse effects of glycine ingestion at a high dose in human volunteers. Seikatsu Eisei. 2006; 50:27-32.
- Woods SW, Walsh BC, Hawkins KA, Miller TJ, Saksa JR, D'Souza DC, Pearlson GD, Javitt DC, McGlashan TH, Krystal JH. Glycine treatment of the risk syndrome for psychosis: report of two pilot studies. Eur Neuropsychopharmacol. 2013 Aug;23(8):931-40. PubMed
Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Metoprolol Is Linked to Lower Levels of One Nutrient
Natural Medicines records Metoprolol as a medicine that can lower these. This is not an interaction with Glycine — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Read the full Metoprolol nutrient depletion report ›
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Glycine and Metoprolol Together: Common Questions
Is it safe to take Glycine with Metoprolol?
Do Glycine and Metoprolol have any of the same side effects?
Should I take Glycine and Metoprolol at the same time of day?
Are Glycine and Metoprolol used for the same thing?
How was the Glycine and Metoprolol combination checked?
Does Glycine interact with any other medications?
Does Metoprolol interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.