Drug & supplement interaction

Thunder God Vine + Selpercatinib

Selpercatinib brand name: Retevmo.

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

Selpercatinib falls into 2 drug categories that Thunder God Vine can interact with; the most serious is rated moderate. Theoretically, CYP3A4 inhibitors might increase the levels and adverse effects of thunder god vine constituents.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Thunder God Vine and Selpercatinib

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Thunder God Vine interacts with whole categories of medication. Selpercatinib falls into 2 of those categories, so it can interact with Thunder God Vine in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS

1 of 2

Why this applies to Selpercatinib

Selpercatinib falls under CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS — the group Thunder God Vine interacts with.

Theoretically, CYP3A4 inhibitors might increase the levels and adverse effects of thunder god vine constituents.
Inhibitors of CYP3A4 can increase the concentration of triptolide, a thunder god vine constituent, and its derivative (5R)-5-hydroxytriptolide. In vitro research shows that triptolide and (5R)-5-hydroxytriptolide are about 94% and 64% metabolized by CYP3A4, respectively.
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 key point with this pairing: it isn't your cancer medicine, Selpercatinib (Retevmo), that builds up. It's the herb. Selpercatinib can block the liver enzyme CYP3A4, and that same enzyme is what breaks down triptolide, one of the main active compounds in Thunder God Vine. Slow down that cleanup, and the herb's levels can climb, which may raise your odds of its more serious side effects, including liver and stomach problems.

Honestly, this is more theory than proven, based on lab work rather than people taking both together. Still, Thunder God Vine is risky on its own and you're already on a strong cancer drug, so please don't combine them without checking with your oncologist or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Xu Y, Zhang YF, Chen XY, Zhong DF. CYP3A4 inducer and inhibitor strongly affect the pharmacokinetics of triptolide and its derivative in rats. Acta Pharmacol Sin. 2018;39(8):1386-1392. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Selpercatinib also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, thunder god vine might increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that triptolide, a constituent of thunder god vine, inhibits CYP3A4 enzymes in human microsomes. This interaction has not been reported in humans.
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 gist: your body relies on a liver enzyme called CYP3A4 to break down and clear selpercatinib (Retevmo) from your system. Thunder God Vine contains a compound (triptolide) that may slow that enzyme down. If selpercatinib isn't cleared as quickly, its levels could creep up, and that may mean more of its known side effects, things like high blood pressure, liver enzyme changes, fatigue, swelling, diarrhea, or effects on your heart rhythm (QT prolongation).

I want to be honest about the strength of this, though. So far this is only seen in lab (test tube) studies, not in actual people, so it's theoretical. Still, selpercatinib is a serious cancer medicine, so don't combine it with this herb without first checking with your oncologist or pharmacist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Song W, Liu M, Wu J, Zhai H, Chen Y, Peng Z. Preclinical Pharmacokinetics of Triptolide: A Potential Antitumor Drug. Curr Drug Metab. 2019;20(2):147-154. 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

Thunder God Vine Also Interacts With Other Medications

Thunder God Vine has 848 moderate known drug interactions in our database — the Selpercatinib one above is among them. If you take anything else, check it against the full list below.

Moderate 848 No known interaction 1,982 (incl. Selpercatinib)
Taking anything else?

Check Another of Your Medications Against Thunder God Vine

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

Everything else you take

See Every Supplement That Interacts With Selpercatinib

This page covers Thunder God Vine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Selpercatinib page lists 178 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 11 major · 132 moderate · 35 minor.

From our pharmacist’s overview on the Selpercatinib page

“People facing a RET-driven lung or thyroid cancer often add supplements for strength, sleep, or immune support, and with selpercatinib (Retevmo) that instinct needs a careful check. Eleven of the 178 ingredients here carry a major rating, and the largest cluster affects how the drug is cleared by the CYP3A4 enzyme: St.”

Reviewed by 2 · Jul 18, 2026

Open the Selpercatinib interaction page

How much people look this up

Where Thunder God Vine and Selpercatinib 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 Thunder God Vine
Steady interest

#1,167 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Selpercatinib
Top 25%

#393 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 Thunder God Vine

What is Thunder God Vine?

Thunder God Vine
  • Rheumatoid arthritis
  • Lupus and autoimmune conditions
  • Inflammation
  • Skin conditions like psoriasis
  • Immune-related disorders

Thunder God Vine is a Chinese herb studied mainly for rheumatoid arthritis and other autoimmune conditions, with some promising but limited evidence. It can be toxic if prepared or dosed improperly, and may cause serious side effects, so it should only be used under medical supervision. Avoid it during pregnancy and breastfeeding.

Read the full Thunder God Vine monograph & all interactions
Medication

About Selpercatinib

What Is Selpercatinib Used For?

Brand name: Retevmo

Selpercatinib treats cancers driven by changes in the RET gene — either a gene fusion (where RET joins abnormally with another gene) or a RET mutation (a change in the gene itself). Your doctor will confirm one of these changes with an FDA-approved test before prescribing it.

It is approved for adults with RET fusion-positive non-small cell lung cancer; adults and children 2 and older with RET-mutant medullary thyroid cancer or RET fusion-positive thyroid cancer; and adults and children 2 and older with other advanced solid tumors that have a RET gene fusion and have not responded to prior treatment.

See full Selpercatinib drug information
Keep checking

Other Drugs & Thunder God Vine

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

0Major
848Moderate
0Minor
1,981No known interaction
848 Moderate 1,981 No interaction
Moderate

848 interactions

Showing 60 of 848 moderate interactions — see all 848 on the Thunder God Vine page.

No interaction 1,981 drugs checked — show the list

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

Showing the 60 most looked-up of 1,981 medications checked with no known interaction — see the full Thunder God Vine list.

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

Can you take Thunder God Vine with Selpercatinib?
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.
Why are there 2 interactions listed for Thunder God Vine and Selpercatinib?
Selpercatinib belongs to more than one drug category, and Thunder God Vine interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Thunder God Vine and Selpercatinib 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 Selpercatinib and Thunder God Vine?

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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.