Drug & supplement interaction

White Oak + Niraparib Tosylate

Niraparib Tosylate brand name: Zejula.

No Known Interaction
The bottom line No known interaction

We found no known interaction between White Oak and Niraparib Tosylate 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.

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Interaction report

White Oak and Niraparib Tosylate

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 Niraparib Tosylate and White Oak 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 White Oak at all — not against Niraparib Tosylate, 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.

White Oak safety at a glance

White Oak overall Use caution Generally used short-term, but its high tannin content can irritate the digestive tract and is not well studied.
Pregnancy Avoid Not enough safety data, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid use.

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

Still wondering about combining Niraparib Tosylate and White Oak? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Niraparib Tosylate’s Own FDA Label Lists

This is not an interaction — none of it involves White Oak. These are the most notable effects listed in the ADVERSE REACTIONS section of Niraparib Tosylate’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. 8 of them are worth acting on rather than waiting out — marked below.

  • Low magnesium Worth acting on
  • Raised blood pressure Worth acting on mentioned in 5.9% of FDA reports for Niraparib Tosylate
  • A low platelet count Worth acting on
  • Kidney problems Worth acting on
  • Anemia Worth acting on
  • Shortness of breath Worth acting on
  • A low white blood cell count Worth acting on
  • A higher chance of infection Worth acting on
  • A change in taste
  • Reduced appetite mentioned in 7.8% of FDA reports for Niraparib Tosylate

Showing the 10 most notable of 27 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 Niraparib Tosylate. Read the label on DailyMed › Where a percentage is shown, it is the share of 51 voluntary FDA FAERS reports for Niraparib Tosylate that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. White Oak’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no White Oak side to compare — that is a limit of the record, not a statement that White Oak has no side effects.

Everything else you take

See Every Supplement That Interacts With Niraparib Tosylate

This page covers White Oak only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Niraparib Tosylate page lists 54 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), St. John's Wort (major), Bitter Melon (moderate), Black Pepper (moderate) and Bulbine Natalensis (moderate).

By severity: 2 major · 35 moderate · 17 minor.

From our pharmacist’s overview on the Niraparib Tosylate page

“Activated charcoal, popular for bloating and so-called detox routines, can trap niraparib (Zejula) in the gut before it absorbs, and St. John's wort can drive levels of the drug down another way.”

Reviewed by 2 · Jul 18, 2026

Open the Niraparib Tosylate interaction page

One more smart check

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

We hold 132 real supplement products containing White Oak, each one broken down to its full ingredient list — and combination products often carry several ingredients besides White Oak. Even though White Oak itself has no known interaction with Niraparib Tosylate, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where White Oak and Niraparib Tosylate 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 White Oak
Steady interest

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

29 days ago today
Medication Niraparib Tosylate
Steady interest

#2,452 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. White Oak 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 White Oak reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The White Oak and Niraparib Tosylate 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 White Oak

What is White Oak?

  • Diarrhea
  • Sore throat and mouth irritation
  • Minor skin inflammation and wounds
  • Hemorrhoids
  • Excessive sweating (topical)

White oak bark is a traditional herbal remedy rich in tannins, used mostly as a tea or skin wash for diarrhea, sore throat, and minor skin problems. Solid human evidence is very limited, and the high tannin content can irritate the stomach, so it should be used cautiously and not for long periods. Talk to a pharmacist or doctor before using it, especially during pregnancy or breastfeeding.

Quercus alba · Fagaceae · Bark (mainly inner bark) · Dried bark, tea/decoction, liquid extract, tincture, powder, capsules, topical washes

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

White Oak: dosing

There is no well-established, standardized dose for white oak bark, and the amount of active tannins can vary a lot between products.Traditional preparations include teas (decoctions) of the bark taken by mouth, and stronger washes or compresses used on the skin or as a gargle.

From our White Oak monograph — the full record covers uses, side effects and every documented interaction.

Read the full White Oak monograph & all interactions
Medication

About Niraparib

What Is Niraparib Used For?

Brand name: Zejula

Zejula is used as maintenance therapy — meaning it is taken after chemotherapy to help keep the cancer from coming back — for adults with advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer. For first-line maintenance, Zejula is approved for patients whose cancer is HRD-positive (has certain DNA-repair defects, including BRCA mutations or genomic instability) and who have responded to their first round of platinum-based chemotherapy.

Zejula is also approved for maintenance treatment in adults with recurrent ovarian, fallopian tube, or primary peritoneal cancer that carries a germline BRCA mutation (an inherited change in the BRCA gene), when the cancer has responded to platinum-based chemotherapy. In both cases, a companion diagnostic test is required to confirm eligibility before starting Zejula.

Most-Reported Side Effects for Niraparib Tosylate

From FAERS, the FDA’s public side-effect reporting system (51 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Constipation 4 reports
Decreased appetite 4 reports
Fatigue 4 reports
Nausea 4 reports
Prostatic specific antigen increased 4 reports
See full Niraparib drug information
Keep checking

Other Drugs & White Oak

Browse every other medication we’ve checked against White Oak — 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

White Oak References

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

  1. Herbs at a Glance — NIH NCCIH 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 White Oak and Niraparib Tosylate Together: Common Questions

Is it safe to take White Oak with Niraparib Tosylate?
We do not list a known interaction between White Oak and Niraparib Tosylate. 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.
Does Niraparib Tosylate interact with any supplements?
Yes. Niraparib Tosylate has documented interactions with 54 supplements in our database — White Oak is not one of them. The Niraparib Tosylate 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 Niraparib Tosylate and White Oak?

Our pharmacists answer your medication & supplement questions — free.

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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.