Drug & supplement interaction

Thunder God Vine + Ethinyl estradiol, Levonogestrel

Ethinyl estradiol, Levonogestrel brand name: Lybrel.

Moderate Interaction
The bottom line Moderate

Ethinyl estradiol, Levonogestrel falls into 3 drug categories that Thunder God Vine can interact with; the most serious is rated moderate. Theoretically, thunder god vine might increase the levels and clinical effects of CYP1A2 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Thunder God Vine and Ethinyl estradiol, Levonogestrel

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Thunder God Vine interacts with whole categories of medication. Ethinyl estradiol, Levonogestrel falls into 3 of those categories, so it can interact with Thunder God Vine in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

1 of 3

Why this applies to Ethinyl estradiol, Levonogestrel

Ethinyl estradiol, Levonogestrel falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Thunder God Vine interacts with.

Theoretically, thunder god vine might increase the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that triptolide, a constituent of thunder god vine, inhibits CYP1A2 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 your birth control pill Lybrel (ethinyl estradiol and levonorgestrel) and Thunder God Vine. In lab tests, a compound in this herb called triptolide appears to slow down a liver enzyme (CYP1A2) that helps process estrogen. In theory, that could let the estrogen part of your pill build up a bit, which might mean more of the usual hormone-related side effects like nausea, breast tenderness, headaches, or bloating.

I want to be honest with you: this is purely theoretical, based on test-tube research only. It has never been reported in real people, so the risk is uncertain. That said, Thunder God Vine itself can be toxic if not used carefully. Please check with your doctor or pharmacist before combining the two.

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
Moderate

CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS

2 of 3

Ethinyl estradiol, Levonogestrel also falls under CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS.

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 about this pairing. Your birth control pill, Lybrel (ethinyl estradiol and levonorgestrel), can mildly block an enzyme called CYP3A4. Thunder God Vine relies on that very same enzyme to break down its active compounds, like triptolide. So in theory, taking them together could slow the herb's breakdown and let it build up, which may raise the risk of Thunder God Vine's side effects (things like stomach upset, or with higher exposure, more serious liver and other toxicity).

I'll be honest, this is a theoretical concern based on lab studies, not real-world reports, so don't panic. But since Thunder God Vine can be genuinely toxic, please loop in your doctor or pharmacist before combining them.

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

3 of 3

Ethinyl estradiol, Levonogestrel 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

Your birth control pill (Lybrel) contains two active hormones, ethinyl estradiol and levonorgestrel, and your body partly clears the estrogen using a liver enzyme called CYP3A4. Thunder God Vine has a compound, triptolide, that may slow that enzyme down. In theory, slowing it could let estrogen levels climb a little higher than usual.

If that happened, you might notice more estrogen-type side effects like nausea, breast tenderness, headaches, or bloating. I want to be honest, though: this is only a lab-dish finding and has never actually been reported in people, so it's more caution than alarm. Thunder God Vine can also be toxic on its own. Please loop in your doctor or pharmacist before combining the two.

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 Ethinyl estradiol, Levonogestrel one above is among them. If you take anything else, check it against the full list below.

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 Ethinyl estradiol, Levonogestrel

This page covers Thunder God Vine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ethinyl estradiol, Levonogestrel page lists 239 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 195 moderate · 38 minor.

From our pharmacist’s overview on the Ethinyl estradiol, Levonogestrel page

“A daily birth control pill like Lybrel (ethinyl estradiol with levonorgestrel) only works when enough hormone stays in the bloodstream, and that is exactly what several supplements on this page can undermine. This list deserves genuine care, starting with the six major-rated entries.”

Reviewed by 2 · Jul 18, 2026

Open the Ethinyl estradiol, Levonogestrel interaction page

How much people look this up

Where Thunder God Vine and Ethinyl estradiol, Levonogestrel 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

#1,020 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Ethinyl estradiol, Levonogestrel
Top 25%

#451 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
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
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
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

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Pharmacist Counseling Corner

Taking Thunder God Vine and Ethinyl estradiol, Levonogestrel Together: Common Questions

Can you take Thunder God Vine with Ethinyl estradiol, Levonogestrel?
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 3 interactions listed for Thunder God Vine and Ethinyl estradiol, Levonogestrel?
Ethinyl estradiol, Levonogestrel 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 Ethinyl estradiol, Levonogestrel 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.