Drug & supplement interaction

Korean Pine + Guanethidine Monosulfate

Guanethidine Monosulfate brand names: Ismelin, Isimil.

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

Korean Pine has a moderate interaction with Guanethidine Monosulfate. Animal research shows that Korean pine nut oil reduces blood pressure in spontaneously hypertensive rats.

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

Korean Pine and Guanethidine Monosulfate

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Guanethidine Monosulfate

Guanethidine Monosulfate falls under ANTIHYPERTENSIVE DRUGS — the group Korean Pine interacts with.

Animal research shows that Korean pine nut oil reduces blood pressure in spontaneously hypertensive rats. Theoretically, Korean pine may increase the risk of hypotension when used in combination with drugs that lower 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

Guanethidine is a strong, older blood pressure medicine that works by lowering the activity of nerves that tighten your blood vessels. Here's the idea behind this interaction: in rat studies, Korean pine nut oil nudged blood pressure down a bit on its own. So the worry is that pairing it with guanethidine could stack two blood-pressure-lowering effects together, possibly pushing your numbers too low.

If that happened, you might feel dizzy or lightheaded, especially standing up, tired, or even faint. I'll be honest though, this is theoretical and based on animal data, not real human cases. Eating pine nuts as food is very unlikely to matter. Concentrated pine extracts are the bigger unknown, so just run those by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sugano M, Ikeda I, Wakamatsu K, Oka T. Influence of Korean pine (Pinus koraiensis)-seed oil containing cis-5,cis-9,cis-12-octadecatrienoic acid on polyunsaturated fatty acid metabolism, eicosanoid production and blood pressure of rats. Br J Nutr 1994;72(5

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

Korean Pine Also Interacts With Other Medications

Korean Pine has 171 moderate known drug interactions in our database — the Guanethidine Monosulfate one above is one of them. If you take anything else, check it against the full list below.

Moderate 171 No known interaction 2,659 (incl. Guanethidine Monosulfate)
Taking anything else?

Check Another of Your Medications Against Korean Pine

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

Everything else you take

See Every Supplement That Interacts With Guanethidine Monosulfate

This page covers Korean Pine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Guanethidine Monosulfate 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 Guanethidine Monosulfate page

“Guanethidine monosulfate (Ismelin) is a forceful older drug for severe high blood pressure, and its interaction list warrants genuine care. Nearly all 137 supplements and herbs on file pull blood pressure one way or the other, either adding to the drug's effect and risking dizziness and faints, or pushing pressure back up and undoing t…”

Reviewed by 2 · Jul 18, 2026

Open the Guanethidine Monosulfate interaction page

One more smart check

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

We hold 2 real supplement products containing Korean Pine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Korean Pine. Your product may carry other ingredients that interact with Guanethidine Monosulfate too, on top of Korean Pine — 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 Korean Pine and Guanethidine Monosulfate 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 Korean Pine
Top half

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

29 days ago today
Medication Guanethidine Monosulfate
Steady interest

#1,649 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 Korean Pine

What is Korean Pine?

  • Appetite control and weight management
  • Heart and cholesterol health
  • General nutrition and energy
  • Skin and antioxidant support
  • Cough and respiratory comfort (traditional)

Korean Pine is best known as the source of edible pine nuts and pine nut oil, which are nutritious foods rich in healthy fats. While some early research looks at pine nut oil for appetite and cholesterol, strong human evidence for any specific health benefit is limited. Treat it mainly as a food, and check with your pharmacist or doctor before using concentrated extracts.

Read the full Korean Pine monograph & all interactions
Keep checking

Other Drugs & Korean Pine

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

0Major
171Moderate
0Minor
2,658No known interaction
171 Moderate 2,658 No interaction
Moderate

171 interactions

Showing 60 of 171 moderate interactions — see all 171 on the Korean Pine page.

No interaction 2,658 drugs checked — show the list

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

Showing the 60 most looked-up of 2,658 medications checked with no known interaction — see the full Korean Pine list.

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

Can you take Korean Pine with Guanethidine Monosulfate?
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 Korean Pine and Guanethidine Monosulfate 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 Guanethidine Monosulfate and Korean Pine?

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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.