Drug & supplement interaction

Oregano + Pentoxifylline

Pentoxifylline brand name: Trental.

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

Oregano has a moderate interaction with Pentoxifylline. Theoretically, oregano might increase the risk of bleeding when taken 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

Oregano and Pentoxifylline

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

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Pentoxifylline

Pentoxifylline falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Oregano interacts with.

Theoretically, oregano might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro research shows that aristolochic acid isolated from oregano leaves has antithrombin activity. It has also been reported that oregano oil inhibits arachidonic acid-induced, and ADP-induced, platelet aggregation.
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

Here's the thing to keep in mind with pentoxifylline (Trental): it already works by making your blood a little less sticky and easier to flow, and it has a mild effect on your platelets too. Concentrated oregano oil may do something similar in the body, at least based on lab studies. Stack the two together and you could, in theory, nudge up your bleeding risk a bit, think easier bruising, nosebleeds, or bleeding gums.

I want to be honest about how soft this evidence is. This concern comes from test-tube research, not real patient cases, so it's theoretical. Sprinkling oregano on your pasta is not a worry at all. The caution is really about concentrated oregano oil capsules. If you're thinking about those, just run it past your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Tognolini, M., Barocelli, E., Ballabeni, V., Bruni, R., Bianchi, A., Chiavarini, M., and Impicciatore, M. Comparative screening of plant essential oils: phenylpropanoid moiety as basic core for antiplatelet activity. Life Sci. 2-23-2006;78(13):1419-1432. PubMed
  2. Goun, E., Cunningham, G., Solodnikov, S., Krasnykch, O., and Miles, H. Antithrombin activity of some constituents from Origanum vulgare. Fitoterapia 2002;73(7-8):692-694. 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

Oregano Also Interacts With Other Medications

Oregano has 207 moderate known drug interactions in our database — the Pentoxifylline one above is one of them. If you take anything else, check it against the full list below.

Moderate 207 No known interaction 2,623 (incl. Pentoxifylline)
Taking anything else?

Check Another of Your Medications Against Oregano

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

From our Q&A

Questions About Oregano or Pentoxifylline

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

This page covers Oregano only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pentoxifylline page lists 218 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), Aconite (moderate) and Allspice (moderate).

By severity: 3 major · 190 moderate · 25 minor.

From our pharmacist’s overview on the Pentoxifylline page

“Pentoxifylline (Trental) improves blood flow in people with poor leg circulation partly by making platelets less sticky, so treat this list as one to read carefully rather than skim. Of the 218 supplements on file, 202 can also slow clotting, which means adding them stacks bleeding risk on bleeding risk.”

Reviewed by 2 · Jul 18, 2026

Open the Pentoxifylline interaction page

One more smart check

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

We hold 1,632 real supplement products containing Oregano, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Oregano. Your product may carry other ingredients that interact with Pentoxifylline too, on top of Oregano — 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 Oregano and Pentoxifylline 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 Oregano
Top 10%

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

29 days ago today
Medication Pentoxifylline
Top half

#859 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 Oregano

What is Oregano?

Oregano
  • Digestive upset
  • Respiratory and cold symptoms
  • Antimicrobial support
  • Intestinal parasites
  • Skin and fungal concerns

Oregano is a common Mediterranean cooking herb that is also sold as a concentrated oil or supplement, often standardized for a compound called carvacrol. While lab studies suggest it may have antimicrobial and antioxidant properties, strong human evidence for treating any specific health condition is limited. Used as a food, oregano is very safe; concentrated oregano oil supplements should be used cautiously and discussed with your pharmacist or doctor.

Read the full Oregano monograph & all interactions
Medication

About Pentoxifylline

What Is Pentoxifylline Used For?

Brand name: Trental

Pentoxifylline Extended-Release Tablets are used to treat intermittent claudication — leg pain, cramping, or fatigue that happens during walking because narrowed arteries aren't delivering enough blood to the muscles. The underlying cause is chronic occlusive arterial disease, a condition where the arteries in the limbs become blocked or narrowed over time.

Pentoxifylline can help improve walking distance and reduce symptoms, but it is not a substitute for procedures that physically open or bypass blocked arteries when those treatments are needed.

See full Pentoxifylline drug information
Keep checking

Other Drugs & Oregano

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

0Major
207Moderate
0Minor
2,622No known interaction
207 Moderate 2,622 No interaction
Moderate

207 interactions

Showing 60 of 207 moderate interactions — see all 207 on the Oregano page.

No interaction 2,622 drugs checked — show the list

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

Showing the 60 most looked-up of 2,622 medications checked with no known interaction — see the full Oregano list.

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

Can you take Oregano with Pentoxifylline?
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 Oregano and Pentoxifylline 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 Pentoxifylline and Oregano?

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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.