Drug & supplement interaction

Cannabis + Fluphenazine

Fluphenazine brand names: Prolixin, Permitil, Fluphenazine.

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

Cannabis has a minor interaction with Fluphenazine. Cannabis does not seem to affect blood levels or effects of some antipsychotic drugs.

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

Cannabis and Fluphenazine

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

Minor

ANTIPSYCHOTIC DRUGS

Why this applies to Fluphenazine

Fluphenazine falls under ANTIPSYCHOTIC DRUGS — the group Cannabis interacts with.

Cannabis does not seem to affect blood levels or effects of some antipsychotic drugs.
Human research shows that cannabis use does not affect blood levels or clinical effects of amisulpride, aripiprazole, or olanzapine in patients with schizophrenia and related disorders.
Severity Minor Likelihood Unlikely Evidence B

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the good news on this pairing: the research we have suggests cannabis doesn't seem to change the blood levels or effectiveness of antipsychotics like fluphenazine. So from a drug-level standpoint, your fluphenazine should keep working about the same whether or not cannabis is in the picture. This is rated as a minor, unlikely interaction.

That said, I'd still bring this up with your doctor. Cannabis on its own can affect mood, thinking, and perception, and in some people THC can stir up anxiety, paranoia, or confusion. Since fluphenazine treats serious symptoms like hallucinations and delusions, you don't want anything working against that progress. You may also feel more drowsy or dizzy when combining them, so go slow and check in with your care team.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Alisauskiene R, Johnsen E, Gjestad R, et al. Does drug use affect the efficacy of amisulpride, aripiprazole and olanzapine in patients with schizophrenia spectrum disorders? Results from a pragmatic, randomised study. Gen Hosp Psychiatry 2023;83:185-193. 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

Cannabis Also Interacts With Other Medications

Cannabis has 2 major, 1,109 moderate, 24 minor known drug interactions in our database — the Fluphenazine one above is one of them. If you take anything else, check it against the full list below.

Major 2 Moderate 1,109 Minor 24 No known interaction 1,695 (incl. Fluphenazine)
Taking anything else?

Check Another of Your Medications Against Cannabis

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

From our Q&A

Questions About Cannabis or Fluphenazine

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

This page covers Cannabis only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fluphenazine page lists 148 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Indian Snakeroot (major), Rauvolfia Vomitoria (major) and Scopolia (major).

By severity: 5 major · 109 moderate · 34 minor.

From our pharmacist’s overview on the Fluphenazine page

“Take real care with supplements while on fluphenazine (Prolixin), an antipsychotic used mainly for schizophrenia. Five of the 148 ingredients on file rate major: herbs like henbane that stack anticholinergic side effects (dry mouth, blurred vision, confusion) onto a drug already prone to them, two rauwolfia plants that can intensify it…”

Reviewed by 2 · Jul 18, 2026

Open the Fluphenazine interaction page

One more smart check

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

We hold 21 real supplement products containing Cannabis, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cannabis. Your product may carry other ingredients that interact with Fluphenazine too, on top of Cannabis — 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 Cannabis and Fluphenazine 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 Cannabis
Top 25%

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

29 days ago today
Medication Fluphenazine
Top half

#1,014 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 Cannabis

What is Cannabis?

Cannabis
  • Chronic pain
  • Nausea and vomiting from chemotherapy
  • Muscle spasticity (e.g., multiple sclerosis)
  • Anxiety and stress
  • Sleep problems
  • Appetite stimulation

Cannabis contains many active compounds, mainly THC (which causes a 'high') and CBD (which does not). Some uses, such as chemotherapy-related nausea, certain seizure disorders, and muscle spasticity, have meaningful evidence, while many other popular uses are not well proven. It can cause real side effects and impairment, so talk to your doctor or pharmacist and follow your local laws before using it.

Read the full Cannabis monograph & all interactions
Medication

About Fluphenazine

What Is Fluphenazine Used For?

Brand names: Prolixin, Permitil, Fluphenazine

Fluphenazine hydrochloride tablets and oral solution are indicated for the management of psychotic disorders. Fluphenazine Hydrochloride Injection is also used for psychotic disorders and can bridge patients to oral therapy.

Fluphenazine Decanoate Injection is a long-acting form specifically intended for patients who need extended antipsychotic treatment — for example, those with chronic schizophrenia who benefit from a single injection that can last up to four weeks or longer. It is not approved for behavioral problems related to intellectual disability, and it is not approved for dementia-related psychosis in elderly patients.

See full Fluphenazine drug information
Keep checking

Other Drugs & Cannabis

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

2Major
1,109Moderate
24Minor
1,694No known interaction
2 Major 1,109 Moderate 24 Minor 1,694 No interaction
Major

2 interactions

Moderate

1,109 interactions

Showing 60 of 1,109 moderate interactions — see all 1,109 on the Cannabis page.

Minor

24 interactions

No interaction 1,694 drugs checked — show the list

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

Showing the 60 most looked-up of 1,694 medications checked with no known interaction — see the full Cannabis list.

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

Can you take Cannabis with Fluphenazine?
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 Cannabis and Fluphenazine 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 Fluphenazine and Cannabis?

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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.