Drug & supplement interaction

Umckaloabo + Pentoxifylline

Pentoxifylline brand name: Trental.

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

Umckaloabo has a minor interaction with Pentoxifylline. Theoretically, Pelargonium sidoides might increase the risk of bleeding when taken with anticoagulant and antiplatelet drugs.

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

Umckaloabo and Pentoxifylline

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

Minor

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Pentoxifylline

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

Theoretically, Pelargonium sidoides might increase the risk of bleeding when taken with anticoagulant and antiplatelet drugs.
Pelargonium sidoides contains coumarin, which may reduce platelet aggregation. However, in animal models, Pelargonium sidoides extract does not appear to inhibit coagulation or interact with warfarin. This interaction has not been documented 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 with Umckaloabo (Pelargonium sidoides) and pentoxifylline. Pentoxifylline already thins the blood a little by making it flow more easily through small vessels, and this root extract contains coumarin-like compounds that, in theory, could nudge in the same direction by making platelets a touch less sticky. Stacked together, the concern is a slightly higher chance of bleeding or bruising, like nosebleeds, bleeding gums, or marks on the skin.

That said, I want to keep this in perspective. This is a theoretical concern based on the plant's chemistry, not something seen in people. Animal studies didn't show real blood-thinning effects. So I wouldn't lose sleep over it, but do mention it to your pharmacist or doctor before combining them, especially if you bruise or bleed easily.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Kolodziej H, Kayser O, Radtke OA, et al. Pharmacological profile of extracts of Pelargonium sidoides and their constituents. Phytomedicine 2003;10 Suppl 4:18-24. PubMed
  2. Koch E, Biber A. Treatment of rats with the Pelargonium sidoides extract EPs 7630 has no effect on blood coagulation parameters or on the pharmacokinetics of warfarin. Phytomedicine 2007;14 Suppl 6:40-5. 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

Umckaloabo Also Interacts With Other Medications

Umckaloabo has 121 moderate, 119 minor 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 121 Minor 119 No known interaction 2,590 (incl. Pentoxifylline)
Taking anything else?

Check Another of Your Medications Against Umckaloabo

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

Everything else you take

See Every Supplement That Interacts With Pentoxifylline

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

We hold 77 real supplement products containing Umckaloabo, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Umckaloabo. Your product may carry other ingredients that interact with Pentoxifylline too, on top of Umckaloabo — 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 Umckaloabo 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 Umckaloabo
Top half

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

29 days ago today
Medication Pentoxifylline
Top half

#839 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 Umckaloabo

What is Umckaloabo?

Umckaloabo
  • Acute bronchitis
  • Common cold
  • Sinusitis
  • Sore throat
  • Upper respiratory infections

Umckaloabo is a root extract from a South African geranium that is most studied for short-term relief of acute bronchitis and other respiratory infections. Some clinical research suggests it may help symptoms resolve a bit faster, but the quality of evidence is mixed and it is not a cure. Talk to your pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or have a chronic illness.

Read the full Umckaloabo 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 & Umckaloabo

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

0Major
121Moderate
119Minor
2,589No known interaction
121 Moderate 119 Minor 2,589 No interaction
Moderate

121 interactions

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

Minor

119 interactions

Showing 60 of 119 minor interactions — see all 119 on the Umckaloabo page.

No interaction 2,589 drugs checked — show the list

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

Showing the 60 most looked-up of 2,589 medications checked with no known interaction — see the full Umckaloabo list.

See the full Umckaloabo 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
Umckaloabo 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 Umckaloabo and Pentoxifylline Together: Common Questions

Can you take Umckaloabo with Pentoxifylline?
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 Umckaloabo and Pentoxifylline 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 Pentoxifylline and Umckaloabo?

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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.