Drug & supplement interaction

Thunder God Vine + Lapatinib

Lapatinib brand name: Tykerb.

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

Lapatinib 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 Lapatinib

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. Lapatinib 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 Lapatinib

Lapatinib 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 thing to understand with this pairing: Lapatinib (Tykerb) is one of those medicines that can block the liver enzyme called CYP3A4. Thunder God Vine, on the other hand, leans on that very same enzyme to be broken down and cleared. So if Lapatinib slows that enzyme down, the herb's active compounds (like triptolide) may not clear as quickly and could build up in your body.

That matters because Thunder God Vine can already be quite toxic, and higher levels raise the odds of serious effects like stomach upset, liver problems, or other harm. Right now this is a theoretical concern based on how the drugs behave, not something proven in real patients. Still, given how potent both of these are, please don't combine them without first talking to your oncologist or pharmacist.

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

Lapatinib 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 situation with Tykerb (lapatinib) and Thunder God Vine. Your body relies on an enzyme called CYP3A4 to clear lapatinib out of your system. Lab studies suggest one of the herb's compounds, triptolide, can slow that enzyme down. If that happens in real life, lapatinib could build up higher than intended. Since this is an active cancer drug (not a prodrug), more of it in your blood usually means stronger effects and a greater chance of side effects like diarrhea, nausea, rash, fatigue, or strain on your heart and liver.

That said, this is a theory drawn from test-tube research, and it hasn't been confirmed in people. Still, because lapatinib is a serious medication, please loop in your oncologist or pharmacist before combining the two.

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 Lapatinib 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. Lapatinib)
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 Lapatinib

This page covers Thunder God Vine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lapatinib page lists 143 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 · 100 moderate · 40 minor.

From our pharmacist’s overview on the Lapatinib page

“Of the 143 supplements on file for lapatinib (Tykerb), nearly all press on the same point, the CYP3A4 enzyme that clears this HER2-targeted breast cancer drug. That deserves real caution, since lapatinib only works when its blood level stays in range.”

Reviewed by 2 · Jul 18, 2026

Open the Lapatinib interaction page

How much people look this up

Where Thunder God Vine and Lapatinib 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

#1,155 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Lapatinib
Steady interest

#2,347 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 Lapatinib

What Is Lapatinib Used For?

Brand name: Tykerb

Lapatinib tablets — sold under the brand name Tykerb — are used to treat advanced or metastatic breast cancer in patients whose tumors overexpress the HER2 protein. They are always used in combination with another medicine, not alone.

Tykerb is approved in combination with capecitabine for HER2-positive advanced or metastatic breast cancer in patients who have already received prior treatment including an anthracycline, a taxane, and trastuzumab, and whose disease has progressed on trastuzumab. Tykerb is also approved in combination with letrozole for postmenopausal women with hormone receptor-positive, HER2-positive metastatic breast cancer when hormonal therapy is appropriate.

See full Lapatinib 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 Lapatinib, 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 Lapatinib supplement interactions › Every supplement checked against Lapatinib, ranked by severity Lapatinib 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 Lapatinib Together: Common Questions

Can you take Thunder God Vine with Lapatinib?
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 Lapatinib?
Lapatinib 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 Lapatinib 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

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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.