Drug & supplement interaction

Passion Flower + Buspirone

Buspirone brand name: BuSpar.

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

Passion Flower has a minor interaction with Buspirone. Theoretically, passion flower might decrease the effects of CYP3A4 substrates.

Read the full interaction report
SeverityMinor
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Passion Flower and Buspirone

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

Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Buspirone

Buspirone falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Passion Flower interacts with.

Theoretically, passion flower might decrease the effects of CYP3A4 substrates.
In vitro research suggests that passion flower can induce CYP3A4 enzymes, albeit to a much lower degree than rifampin, a known CYP3A4 inducer.
Severity Minor 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 deal with pairing passion flower and buspirone. Your body relies on a liver enzyme called CYP3A4 to break buspirone down, and some lab studies hint that passion flower might gently speed that enzyme up. If that happens, your body could clear buspirone a little faster, which in theory means a slightly weaker anxiety-calming effect from your dose.

I want to keep this in perspective, though. This is only based on test-tube research, and even then the effect was much weaker than known enzyme boosters like rifampin. So in real life this is unlikely to cause big problems. Still, if you notice your anxiety creeping back after adding passion flower, mention it to your pharmacist or doctor before changing anything.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Mazzari ALDA, Lacerda MG, Milton FA, et al. In vitro effects of European and Latin-American medicinal plants in CYP3A4 gene expression, glutathione levels, and P-glycoprotein activity. Front Pharmacol 2022;13:826395. 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

Passion Flower Also Interacts With Other Medications

Passion Flower has 248 moderate, 587 minor known drug interactions in our database — the Buspirone one above is one of them. If you take anything else, check it against the full list below.

Moderate 248 Minor 587 No known interaction 1,995 (incl. Buspirone)
Taking anything else?

Check Another of Your Medications Against Passion Flower

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

From our Q&A

Questions About Passion Flower or Buspirone

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Passion Flower or Buspirone, 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 Buspirone

This page covers Passion Flower only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Buspirone page lists 155 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Lithium (major), St. John's Wort (major) and 5-htp (moderate).

By severity: 4 major · 108 moderate · 43 minor.

From our pharmacist’s overview on the Buspirone page

“I counsel genuine caution when supplements meet buspirone (BuSpar), the anxiety medication, because four of its 155 documented interactions are rated major. The bulk of the list, 121 ingredients, changes how your liver clears buspirone through the CYP3A4 enzyme, pushing its level up toward dizziness and drowsiness or down until the anx…”

Reviewed by 2 · Jul 18, 2026

Open the Buspirone interaction page

One more smart check

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

We hold 2,129 real supplement products containing Passion Flower, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Passion Flower. Your product may carry other ingredients that interact with Buspirone too, on top of Passion Flower — 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 Passion Flower and Buspirone 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 Passion Flower
Top 10%

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

29 days ago today
Medication Buspirone
Top 5%

#54 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 Passion Flower

What is Passion Flower?

Passion Flower
  • Anxiety and stress
  • Trouble sleeping
  • Restlessness
  • Mild nervous tension
  • Muscle tension

Passion flower is a traditional calming herb that many people use for anxiety and sleep. Early studies hint it may help with mild anxiety and restlessness, but the evidence is limited and more research is needed. It is generally well tolerated short-term, but should be avoided in pregnancy and discussed with your pharmacist or doctor first.

Read the full Passion Flower monograph & all interactions
Medication

About Buspirone

What Is Buspirone Used For?

Brand name: BuSpar

Buspirone tablets and capsules are used to manage anxiety disorders or to relieve anxiety symptoms in the short term. Its effectiveness has been shown in clinical trials focused on Generalized Anxiety Disorder (GAD) — a condition marked by persistent, hard-to-control worry along with physical symptoms like muscle tension, restlessness, difficulty concentrating, and sleep problems.

Buspirone has also been shown to relieve anxiety in people who have mild depressive symptoms alongside their anxiety. Everyday stress and tension, on their own, generally do not require treatment with a medicine like buspirone.

See full Buspirone drug information
Keep checking

Other Drugs & Passion Flower

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

0Major
248Moderate
587Minor
1,994No known interaction
248 Moderate 587 Minor 1,994 No interaction
Moderate

248 interactions

Showing 60 of 248 moderate interactions — see all 248 on the Passion Flower page.

Minor

587 interactions

Showing 60 of 587 minor interactions — see all 587 on the Passion Flower page.

No interaction 1,994 drugs checked — show the list

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

Showing the 60 most looked-up of 1,994 medications checked with no known interaction — see the full Passion Flower list.

See the full Passion Flower interactions page
See every supplement checked against Buspirone, 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
Passion Flower monograph › Uses, safety, and every drug interaction in one place Buspirone supplement interactions › Every supplement checked against Buspirone, ranked by severity Buspirone 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 Passion Flower and Buspirone Together: Common Questions

Can you take Passion Flower with Buspirone?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Passion Flower and Buspirone interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Buspirone and Passion Flower?

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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.