Drug & supplement interaction

Saw Palmetto + Phenprocoumon

Phenprocoumon brand name: Liquamar.

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

Saw Palmetto has a moderate interaction with Phenprocoumon. Saw palmetto might increase the risk of bleeding with anticoagulant or antiplatelet drugs.

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

Saw Palmetto 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 Saw Palmetto interacts with.

Saw palmetto might increase the risk of bleeding with anticoagulant or antiplatelet drugs.
Saw palmetto is reported to prolong bleeding time. Theoretically, it might increase the risk of bleeding when used concomitantly with anticoagulant or antiplatelet drugs.
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 that works a lot like warfarin, and it's a narrow-margin medicine, meaning small shifts can tip you toward too much or too little effect. Saw palmetto has been reported to lengthen bleeding time, so on paper, pairing it with phenprocoumon could nudge you toward easier bleeding. Watch for things like unusual bruising, nosebleeds, bleeding gums, pink or dark urine, or cuts that won't stop.

I want to be honest about the strength of this: it's mostly theoretical and based on scattered case reports, not solid studies. That said, because phenprocoumon is so dose-sensitive, I'd still mention any saw palmetto use to your doctor or pharmacist before starting, and keep your INR checks on schedule.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Cheema P, El-Mefty O, Jazieh AR. Intraoperative haemorrhage associated with the use of extract of Saw Palmetto herb: a case report and review of literature. J Intern Med 2001;250:167-9. 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

Saw Palmetto Also Interacts With Other Medications

Saw Palmetto has 173 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 173 No known interaction 2,657 (incl. Phenprocoumon)
Taking anything else?

Check Another of Your Medications Against Saw Palmetto

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

From our Q&A

Questions About Saw Palmetto or Phenprocoumon

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

This page covers Saw Palmetto 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 Saw Palmetto as Part of a Dietary Supplement Product? Check It for Interactions

We hold 3,466 real supplement products containing Saw Palmetto, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Saw Palmetto. Your product may carry other ingredients that interact with Phenprocoumon too, on top of Saw Palmetto — 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 Saw Palmetto 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 Saw Palmetto
Top 10%

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

29 days ago today
Medication Phenprocoumon
Top half

#760 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 Saw Palmetto

What is Saw Palmetto?

Saw Palmetto
  • Benign prostatic hyperplasia (BPH) symptoms
  • Urinary problems
  • Hair loss
  • Prostate health
  • Inflammation

Saw palmetto is a plant extract most often used for urinary symptoms linked to an enlarged prostate (BPH). The best research suggests it works no better than a placebo for most men, though it is generally well tolerated. Talk to your doctor or pharmacist before using it, especially for prostate or urinary problems that need proper evaluation.

Read the full Saw Palmetto monograph & all interactions
Keep checking

Other Drugs & Saw Palmetto

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

0Major
173Moderate
0Minor
2,656No known interaction
173 Moderate 2,656 No interaction
Moderate

173 interactions

Showing 60 of 173 moderate interactions — see all 173 on the Saw Palmetto page.

No interaction 2,656 drugs checked — show the list

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

Showing the 60 most looked-up of 2,656 medications checked with no known interaction — see the full Saw Palmetto list.

See the full Saw Palmetto 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
Saw Palmetto 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 Saw Palmetto and Phenprocoumon Together: Common Questions

Can you take Saw Palmetto 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 Saw Palmetto 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 Saw Palmetto?

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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.