Drug & supplement interaction

Tansy Ragwort + Apalutamide

Apalutamide brand name: Erleada.

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

Tansy Ragwort has a moderate interaction with Apalutamide. Theoretically, CYP3A4 inducers might increase the risk of adverse effects from the pyrrolizidine alkaloid (PA) constituents in tansy ragwort.

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

Tansy Ragwort and Apalutamide

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) INDUCERS

Why this applies to Apalutamide

Apalutamide falls under CYTOCHROME P450 3A4 (CYP3A4) INDUCERS — the group Tansy Ragwort interacts with.

Theoretically, CYP3A4 inducers might increase the risk of adverse effects from the pyrrolizidine alkaloid (PA) constituents in tansy ragwort.
Tansy ragwort contains PAs. PAs are substrates of CYP3A4. Theoretically, drugs that induce CYP3A4 might increase the conversion of PAs to toxic metabolites.
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

First things first: I'd steer you away from tansy ragwort entirely. It's a toxic weed packed with pyrrolizidine alkaloids that can seriously harm your liver, and there's no good evidence it helps anything. That advice stands on its own, no matter what else you take.

Here's the wrinkle with Erleada (apalutamide). Your body has to activate those plant alkaloids into their harmful forms using an enzyme called CYP3A4, and apalutamide actually speeds that enzyme up. So in theory, taking the two together could push your body to make more of the toxic, liver-damaging byproducts. I want to be straight with you, though: this concern comes only from lab and animal data, so it's theoretical, not proven in people. The safest move is simply to avoid the herb and check with your oncology team or pharmacist before adding any supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chojkier M. Hepatic sinusoidal-obstruction syndrome: toxicity of pyrrolizidine alkaloids. J Hepatol 2003;39:437-46. PubMed
  2. Wang YP, Yan J, Fu PP, Chou MW. Human liver microsomal reduction of pyrrolizidine alkaloid N-oxides to form the corresponding carcinogenic parent alkaloid. Toxicol Lett 2005;155:411-20. 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

Tansy Ragwort Also Interacts With Other Medications

Tansy Ragwort has 86 moderate known drug interactions in our database — the Apalutamide one above is one of them. If you take anything else, check it against the full list below.

Moderate 86 No known interaction 2,744 (incl. Apalutamide)
Taking anything else?

Check Another of Your Medications Against Tansy Ragwort

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

Everything else you take

See Every Supplement That Interacts With Apalutamide

This page covers Tansy Ragwort only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Apalutamide page lists 155 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 113 moderate · 39 minor.

From our pharmacist’s overview on the Apalutamide page

“Apalutamide (Erleada) treats prostate cancer, and it only works when its blood level stays where it should, so approach this list with genuine care. Three of the 155 ingredients on file are rated major: grapefruit can push apalutamide levels up, St.”

Reviewed by 2 · Jul 18, 2026

Open the Apalutamide interaction page

How much people look this up

Where Tansy Ragwort and Apalutamide 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 Tansy Ragwort
Steady interest

#1,060 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Apalutamide
Steady interest

#1,937 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 Tansy Ragwort

What is Tansy Ragwort?

  • Traditional wound and skin washes
  • Folk remedy for sore throat (gargle)
  • Topical poultice for joint or muscle aches
  • Historical use for menstrual complaints

Tansy ragwort is a toxic weed that contains pyrrolizidine alkaloids, which can seriously damage the liver. It is not recommended as a supplement or home remedy, and there is no reliable evidence that it safely treats any condition. Avoid taking it internally and talk to a pharmacist or doctor before using any herbal product.

Read the full Tansy Ragwort monograph & all interactions
Medication

About Apalutamide

What Is Apalutamide Used For?

Brand name: Erleada

Erleada (apalutamide) is used to treat two types of prostate cancer. The first is metastatic castration-sensitive prostate cancer (mCSPC) — prostate cancer that has spread to other parts of the body and still responds to hormone-lowering therapy. The second is non-metastatic castration-resistant prostate cancer (nmCRPC) — prostate cancer that has stopped responding to standard hormone therapy but has not yet spread to other organs.

Erleada is always used alongside a gonadotropin-releasing hormone (GnRH) analog — a medicine that lowers testosterone — or in patients who have already had surgery to remove the testicles.

See full Apalutamide drug information
Keep checking

Other Drugs & Tansy Ragwort

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

0Major
86Moderate
0Minor
2,743No known interaction
86 Moderate 2,743 No interaction
Moderate

86 interactions

Showing 60 of 86 moderate interactions — see all 86 on the Tansy Ragwort page.

No interaction 2,743 drugs checked — show the list

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

Showing the 60 most looked-up of 2,743 medications checked with no known interaction — see the full Tansy Ragwort list.

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

Can you take Tansy Ragwort with Apalutamide?
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 Tansy Ragwort and Apalutamide 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 Apalutamide and Tansy Ragwort?

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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.