Drug & supplement interaction

Basil + Metoprolol

Metoprolol brand names: Lopressor, Toprol XL.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Basil has a moderate interaction with Metoprolol. Theoretically, basil might increase the risk of hypotension when taken with antihypertensive drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Basil and Metoprolol

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Metoprolol

Metoprolol falls under ANTIHYPERTENSIVE DRUGS — the group Basil interacts with.

Theoretically, basil might increase the risk of hypotension when taken with antihypertensive drugs.
Animal research suggests that basil extract can reduce systolic and diastolic blood pressure.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version: metoprolol already lowers your blood pressure and slows your heart rate. Concentrated basil extracts, in animal studies, have nudged blood pressure down a bit too. Put them together and you could end up a little lower than expected. In real life that might feel like dizziness, lightheadedness when you stand up, unusual tiredness, or a slower-than-usual pulse.

Now the important context: this concern comes only from lab and animal research, not human studies, so it's pretty theoretical. The basil you sprinkle on pasta or pesto won't be an issue. The question is really about concentrated supplements or basil essential oil. If you're considering those, run it by your pharmacist or doctor first, and don't change your metoprolol on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Umar, A., Imam, G., Yimin, W., Kerim, P., Tohti, I., Berke, B., and Moore, N. Antihypertensive effects of Ocimum basilicum L. (OBL) on blood pressure in renovascular hypertensive rats. Hypertens.Res 5-7-2010; PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Basil Also Interacts With Other Medications

Basil has 288 moderate known drug interactions in our database — the Metoprolol one above is one of them. If you take anything else, check it against the full list below.

Moderate 288 No known interaction 2,542 (incl. Metoprolol)
Taking anything else?

Check Another of Your Medications Against Basil

Covers the 2,830 medications we’ve checked against Basil. Pick one to open its full report.

From our Q&A

Questions About Basil 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 Basil 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:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Metoprolol

This page covers Basil 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

Open the Metoprolol interaction page

One more smart check

Taking Basil as Part of a Dietary Supplement Product? Check It for Interactions

We hold 396 real supplement products containing Basil, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Basil. Your product may carry other ingredients that interact with Metoprolol too, on top of Basil — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Basil 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.

Supplement Basil
Top 25%

#338 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Metoprolol
Top 10

#7 of 2,830 medications looked up here in the last 7 days

29 days ago today

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.

Supplement

About Basil

What is Basil?

Basil
  • Digestive upset and gas
  • Stress and anxiety
  • Antimicrobial support
  • Cold and cough symptoms
  • Headache
  • General antioxidant support

Basil is a popular cooking herb that is generally safe in the amounts used in food. While it has a long history of traditional medicinal use and contains antioxidant compounds, strong human evidence for most health claims is limited. Talk with your pharmacist or doctor before using concentrated supplements or essential oils.

Read the full Basil monograph & all interactions
Medication

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.

See full Metoprolol drug information
Keep checking

Other Drugs & Basil

Browse every other medication we’ve checked against Basil — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
288Moderate
0Minor
2,541No known interaction
288 Moderate 2,541 No interaction
Moderate

288 interactions

Showing 60 of 288 moderate interactions — see all 288 on the Basil page.

No interaction 2,541 drugs checked — show the list

We also checked Basil against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,541 medications checked with no known interaction — see the full Basil list.

See the full Basil interactions page
See every supplement checked against Metoprolol, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Basil monograph › Uses, safety, and every drug interaction in one place Metoprolol supplement interactions › Every supplement checked against Metoprolol, ranked by severity Metoprolol drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Basil and Metoprolol Together: Common Questions

Can you take Basil with Metoprolol?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Basil and Metoprolol interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Metoprolol and Basil?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.