Drug & supplement interaction

Cypress + Phenprocoumon

Phenprocoumon brand name: Liquamar.

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

Cypress has a moderate interaction with Phenprocoumon. In vitro evidence shows that cypress cone extract inhibits blood coagulation in a concentration-dependent manner.

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

Cypress and Phenprocoumon

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

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Phenprocoumon

Phenprocoumon falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Cypress interacts with.

In vitro evidence shows that cypress cone extract inhibits blood coagulation in a concentration-dependent manner. In one case report, prolonged bleeding time during surgery occurred in a 52-year-old female undergoing removal of a premalignant skin lesion. Based on preoperative questioning, the patient had no relevant history of systemic disease, drug use, or allergy. Upon postoperative questioning, the patient reported taking cypress cone extract for one year prior to surgery. Theoretically, taking cypress extract along with anticoagulant/antiplatelet drugs might increase the risk of bruising and bleeding in some patients. Some anticoagulant/antiplatelet drugs include aspirin; clopidogrel (Plavix); nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), and naproxen (Anaprox, Naprosyn, others); dalteparin (Fragmin); enoxaparin (Lovenox); heparin; warfarin (Coumadin); and others.
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

Phenprocoumon is a blood thinner, very similar to warfarin, that keeps your blood from clotting too easily. The concern here is simple: cypress cone extract has shown some clot-slowing activity in lab studies, and there's a single case report of longer-than-expected bleeding during surgery in someone who'd been taking it. Stacked on top of a drug that already thins your blood, the worry is that you could bleed or bruise more easily than intended.

I want to be honest that this evidence is thin (one anecdote plus test-tube data), so don't panic. But because phenprocoumon has a narrow safety window where small shifts matter, watch for unusual bruising, nosebleeds, or bleeding gums, and check with your doctor or pharmacist before using cypress, especially as a concentrated supplement rather than just aromatherapy.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ulusal BG, Arikan S, Durusoy C. Anticoagulant effect of Cupressus sempervirens. Phytother Res. 2007 Nov;21(11):1116.

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

Cypress Also Interacts With Other Medications

Cypress has 121 moderate known drug interactions in our database — the Phenprocoumon one above is one of them. If you take anything else, check it against the full list below.

Moderate 121 No known interaction 2,709 (incl. Phenprocoumon)
Taking anything else?

Check Another of Your Medications Against Cypress

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

Everything else you take

See Every Supplement That Interacts With Phenprocoumon

This page covers Cypress only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenprocoumon page lists 219 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Danshen (major), Piracetam (major), St. John's Wort (major) and Aconite (moderate).

By severity: 4 major · 190 moderate · 25 minor.

From our pharmacist’s overview on the Phenprocoumon page

“Phenprocoumon (Liquamar) is a blood thinner in the coumarin family, a close cousin of warfarin, and small shifts in its blood level can tip you toward a clot or a bleed, so I treat this list with genuine care. Almost everything on it pushes the drug's effect further, layering extra bleeding risk on blood that is already thinned.”

Reviewed by 2 · Jul 18, 2026

Open the Phenprocoumon interaction page

One more smart check

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

We hold 13 real supplement products containing Cypress, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cypress. Your product may carry other ingredients that interact with Phenprocoumon too, on top of Cypress — 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 Cypress and Phenprocoumon 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 Cypress
Top half

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

29 days ago today
Medication Phenprocoumon
Top half

#774 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 Cypress

What is Cypress?

  • Circulation and varicose veins
  • Coughs and respiratory complaints
  • Excess sweating
  • Skin and minor wounds
  • Aromatherapy for relaxation

Cypress comes from the Mediterranean cypress tree and is most often used as an essential oil in aromatherapy or skin care, and traditionally for circulation and respiratory complaints. High-quality human evidence for these uses is very limited, so it should not replace proven treatments. The essential oil is for external use only and should be diluted, and you should talk with your pharmacist or doctor before using it.

Read the full Cypress monograph & all interactions
Keep checking

Other Drugs & Cypress

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

0Major
121Moderate
0Minor
2,708No known interaction
121 Moderate 2,708 No interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Cypress page.

No interaction 2,708 drugs checked — show the list

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

Showing the 60 most looked-up of 2,708 medications checked with no known interaction — see the full Cypress list.

See the full Cypress interactions page
See every supplement checked against Phenprocoumon, 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
Cypress monograph › Uses, safety, and every drug interaction in one place Phenprocoumon supplement interactions › Every supplement checked against Phenprocoumon, 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 Cypress and Phenprocoumon Together: Common Questions

Can you take Cypress with Phenprocoumon?
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 Cypress and Phenprocoumon 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 Phenprocoumon and Cypress?

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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.