Drug & supplement interaction

Hemp + Phenoxybenzamine

Phenoxybenzamine brand name: Dibenzyline.

Minor Interaction
The bottom line Minor

Hemp has a minor interaction with Phenoxybenzamine. Theoretically, hemp seed protein may have additive effects with antihypertensive drugs.

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

Hemp and Phenoxybenzamine

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

Minor

ANTIHYPERTENSIVE DRUGS

Why this applies to Phenoxybenzamine

Phenoxybenzamine falls under ANTIHYPERTENSIVE DRUGS — the group Hemp interacts with.

Theoretically, hemp seed protein may have additive effects with antihypertensive drugs.
In a hypertensive animal model, hemp seed protein hydrolysate reduced systolic blood pressure by a mechanism possibly involving the inhibition of renin and angiotensin converting enzyme (ACE) activities. However, there was no effect of hemp seed protein on blood pressure in normotensive animals. Furthermore, hempseed oil consumption does not seem to reduce blood pressure in humans.
Severity Minor Likelihood Unlikely Evidence D

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 gist for phenoxybenzamine (Dibenzyline), which relaxes blood vessels to control the blood pressure spikes and sweating from a pheochromocytoma. The concern on file is purely theoretical: in a lab study using animals with high blood pressure, hemp seed protein nudged blood pressure down a little. Stack that on top of a blood pressure medication and, in theory, you could get an additive effect.

In real life, this is a minor and unlikely worry. Hemp seed oil hasn't lowered blood pressure in human studies, and the food amounts most people eat are very different from concentrated extracts. Still, if you ever feel dizzy, lightheaded, or get a racing heartbeat when standing up, mention it to your pharmacist or doctor rather than changing anything yourself.

References
  1. Girgih AT, Alashi A, He R, Malomo S, Aluko RE. Preventive and treatment effects of a hemp seed (Cannabis sativa L.) meal protein hydrolysate against high blood pressure in spontaneously hypertensive rats. Eur J Nutr. 2014;53(5):1237-46. PubMed
  2. Del Bo' C, Deon V, Abello F, et al. Eight-week hempseed oil intervention improves the fatty acid composition of erythrocyte phospholipids and the omega-3 index, but does not affect the lipid profile in children and adolescents with primary hyperlipidemia. 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

Hemp Also Interacts With Other Medications

Hemp has 41 moderate, 896 minor known drug interactions in our database — the Phenoxybenzamine one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Hemp

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

Everything else you take

See Every Supplement That Interacts With Phenoxybenzamine

This page covers Hemp only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenoxybenzamine page lists 137 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), Tyramine (major) and Adrafinil (moderate).

By severity: 4 major · 112 moderate · 21 minor.

From our pharmacist’s overview on the Phenoxybenzamine page

“Phenoxybenzamine (Dibenzyline) is usually prescribed for pheochromocytoma, an adrenal tumor that sends blood pressure surging, often to steady a patient in the weeks before surgery, so keeping pressure in a narrow band is the entire goal of treatment. That makes this a list to treat carefully rather than skim.”

Reviewed by 2 · Jul 18, 2026

Open the Phenoxybenzamine interaction page

One more smart check

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

We hold 720 real supplement products containing Hemp, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hemp. Your product may carry other ingredients that interact with Phenoxybenzamine too, on top of Hemp — 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 Hemp and Phenoxybenzamine 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 Hemp
Top 25%

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

29 days ago today
Medication Phenoxybenzamine
Top half

#740 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 Hemp

What is Hemp?

Hemp
  • Plant-based protein source
  • Heart health support
  • Skin and hair health
  • Reducing inflammation
  • General nutrition (omega fatty acids)

Hemp seeds and hemp seed oil are nutritious foods rich in protein, fiber, and healthy omega-3 and omega-6 fatty acids, and they are generally safe for most people as part of the diet. While the nutrition is real, strong human evidence that hemp supplements treat specific medical conditions is limited. Talk with your pharmacist or doctor before using hemp products for a health concern, especially if you are pregnant or breastfeeding.

Read the full Hemp monograph & all interactions
Medication

About Phenoxybenzamine

What Is Phenoxybenzamine Used For?

Brand name: Dibenzyline

Phenoxybenzamine hydrochloride capsules are used to treat pheochromocytoma — a rare tumor of the adrenal gland that releases large bursts of stress hormones, causing dangerous spikes in blood pressure and heavy sweating. The capsules help keep those episodes under control.

If the heart rate becomes too fast during treatment, a doctor may also prescribe a beta-blocker alongside phenoxybenzamine.

See full Phenoxybenzamine drug information
Keep checking

Other Drugs & Hemp

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

0Major
41Moderate
896Minor
1,892No known interaction
Moderate

41 interactions

Minor

896 interactions

Showing 60 of 896 minor interactions — see all 896 on the Hemp page.

No interaction 1,892 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Hemp and Phenoxybenzamine Together: Common Questions

Can you take Hemp with Phenoxybenzamine?
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 Hemp and Phenoxybenzamine 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 Phenoxybenzamine and Hemp?

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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.