Drug & supplement interaction

European Five-finger Grass + Pentoxifylline

Pentoxifylline brand name: Trental.

No Known Interaction
The bottom line No known interaction

We found no known interaction between European Five-finger Grass and Pentoxifylline in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Pentoxifylline states a food rule worth keeping to.

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Interaction report

European Five-finger Grass and Pentoxifylline

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Pentoxifylline and European Five-finger Grass in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for European Five-finger Grass at all — not against Pentoxifylline, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

European Five-finger Grass safety at a glance

European Five-fing... overall Use caution Limited safety data exist, so use it cautiously and at modest amounts.
Pregnancy Avoid Not enough safety information is available, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid use unless cleared by your doctor.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Pentoxifylline and European Five-finger Grass? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Pentoxifylline’s Own FDA Label Lists

This is not an interaction — none of it involves European Five-finger Grass. These are the most notable effects listed in the ADVERSE REACTIONS section of Pentoxifylline’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • Shortness of breath Worth acting on mentioned in 9.4% of FDA reports for Pentoxifylline
  • Yellowing of the skin or eyes Worth acting on
  • An irregular heartbeat Worth acting on
  • Confusion Worth acting on
  • Seizures Worth acting on
  • Chest pain Worth acting on
  • Low mood Worth acting on
  • A low platelet count Worth acting on
  • Anemia Worth acting on
  • A severe allergic reaction Worth acting on

Showing the 10 most notable of 39 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Pentoxifylline. Read the label on DailyMed › Where a percentage is shown, it is the share of 4,245 voluntary FDA FAERS reports for Pentoxifylline that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. European Five-finger Grass’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no European Five-finger Grass side to compare — that is a limit of the record, not a statement that European Five-finger Grass has no side effects.

How to take them

Some Pentoxifylline Products Have a Food Rule — European Five-finger Grass Should Not Break It

At least one FDA label for a product containing Pentoxifylline says to take it with food. If you take European Five-finger Grass on an empty stomach out of habit, keep them separate — and take Pentoxifylline with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Pentoxifylline products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

DOSAGE AND ADMINISTRATION The usual dosage of pentoxifylline in extended-release tablet form is one tablet (400 mg) three times a day with meals.

From the Dosage and Administration section of the FDA label we read for Pentoxifylline — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Pentoxifylline

This page covers European Five-finger Grass 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

How much people look this up

Where European Five-finger Grass 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 European Five-finger Grass
Steady interest

#1,021 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Pentoxifylline
Top half

#931 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions. European Five-finger Grass is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every European Five-finger Grass reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The European Five-finger Grass and Pentoxifylline records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About European Five-finger Grass

What is European Five-finger Grass?

European Five-finger Grass
  • Diarrhea
  • Sore throat and mouth rinse
  • Skin irritation
  • Mild inflammation
  • Digestive upset

European Five-finger Grass (Potentilla reptans) is a traditional European herb used mainly for diarrhea, sore throat, and minor skin problems, largely because of its tannin content. There is very little high-quality human research to confirm it works for any condition, so use it cautiously and talk to your pharmacist or doctor first.

Potentilla reptans · Rosaceae · Leaves, flowers, and roots (aerial parts and rhizome) · Tea, liquid extract, tincture, dried herb, topical preparations

An interaction check asks whether these two react with each other — it does not ask whether European Five-finger Grass is a good idea for someone in your situation. Here is what our European Five-finger Grass record says about it on its own.

European Five-finger Grass: dosing

There is no standardized, scientifically established dose for European Five-finger Grass. Traditional use most often involved a tea made from the dried leaves or roots, but exact amounts varied widely.If you choose to use a commercial product, follow the directions on the label and do not exceed the recommended amount. Because product strength can vary a lot between brands, it is wise to start low.

From our European Five-finger Grass monograph — the full record covers uses, side effects and every documented interaction.

Read the full European Five-finger Grass 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.

Most-Reported Side Effects for Pentoxifylline

From FAERS, the FDA’s public side-effect reporting system (4,300 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 457 reports
Diarrhea 431 reports
Dyspnea 405 reports
Fall 376 reports
Dizziness 371 reports
See full Pentoxifylline drug information
Keep checking

Other Drugs & European Five-finger Grass

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

European Five-finger Grass References

The 2 sources that drive our European Five-finger Grass monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. European Five-finger Grass is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Herbs at a Glance — NIH National Center for Complementary and Integrative Health Source
  2. Herbs and Supplements — MedlinePlus Source

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking European Five-finger Grass and Pentoxifylline Together: Common Questions

Is it safe to take European Five-finger Grass with Pentoxifylline?
We do not list a known interaction between European Five-finger Grass and Pentoxifylline. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Should I take European Five-finger Grass and Pentoxifylline at the same time of day?
At least one FDA label for a product containing Pentoxifylline says to take it with food. If you take European Five-finger Grass on an empty stomach out of habit, keep them separate and take Pentoxifylline with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Pentoxifylline products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Does Pentoxifylline interact with any supplements?
Yes. Pentoxifylline has documented interactions with 218 supplements in our database — European Five-finger Grass is not one of them. The Pentoxifylline interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Pentoxifylline and European Five-finger Grass?

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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.