Drug & supplement interaction

Hu Zhang + Ethinyl Estradiol, Norgestrel

Ethinyl Estradiol, Norgestrel brand names: Ovral, Lo/Ovral, Cryselle, Low-Ogestrel, Ogestrel 0.5/50.

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

Ethinyl Estradiol, Norgestrel falls into 3 drug categories that Hu Zhang can interact with; the most serious is rated moderate. Theoretically, hu zhang might increase levels of drugs metabolized by CYP1A2.

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

Hu Zhang and Ethinyl Estradiol, Norgestrel

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

Why Are There 3 Interactions?

Hu Zhang interacts with whole categories of medication. Ethinyl Estradiol, Norgestrel falls into 3 of those categories, so it can interact with Hu Zhang 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, Norgestrel

Ethinyl Estradiol, Norgestrel falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Hu Zhang interacts with.

Theoretically, hu zhang might increase levels of drugs metabolized by CYP1A2.
Hu zhang contains the constituent resveratrol. In vitro research shows that resveratrol might inhibit the CYP1A2 enzyme. 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 with your birth control pill (the ethinyl estradiol and norgestrel combo in Ovral, Lo/Ovral, Cryselle, and similar brands). The estrogen part is partly handled by a liver enzyme called CYP1A2. Hu Zhang contains resveratrol, and in test-tube studies resveratrol may slow that enzyme down. If that happened in your body, your pill's estrogen could build up a bit, which in theory might mean more of the usual estrogen-related effects like nausea, breast tenderness, headaches, or fluid retention.

The honest part: this is only a theoretical concern from lab research, and it hasn't actually been reported in people. I wouldn't lose sleep over it, but since this is your contraception, it's worth a quick chat with your pharmacist or doctor before adding a concentrated Hu Zhang supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chang, T. K., Chen, J., and Lee, W. B. Differential inhibition and inactivation of human CYP1 enzymes by trans-resveratrol: evidence for mechanism-based inactivation of CYP1A2. J.Pharmacol.Exp.Ther. 2001;299(3):874-882.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 3

Ethinyl Estradiol, Norgestrel also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, hu zhang might increase levels of drugs metabolized by CYP3A4.
Hu zhang contains the constituent resveratrol. In vitro research shows that resveratrol might inhibit the CYP3A4 enzyme. However, a clinical study in adults with NAFLD found that adding resveratrol 3000 mg daily for 8 weeks did not necessitate dose adjustments to any established medications metabolized by CYP3A4.
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 (Ovral and similar) contains ethinyl estradiol and norgestrel, both of which your body clears using a liver enzyme called CYP3A4. Hu Zhang is rich in resveratrol, and in test-tube studies resveratrol can slow that same enzyme down. In theory, that could let a little more estrogen and progestin linger in your system, which might mean more of the usual estrogen-type side effects like nausea, breast tenderness, headaches, or bloating.

Here's the reassuring part: this is only a lab-based, theoretical concern. In a real human study, even 3000 mg of resveratrol daily for 8 weeks didn't force any dose changes to CYP3A4 medications. So the risk looks low. Still, since reliable birth control matters, I'd run it by your pharmacist or doctor before adding Hu Zhang.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Piver B, Berthou F, Dreano Y, Lucas D. Inhibition of CYP3A, CYP1A and CYP2E1 activities by resveratrol and other non volatile red wine components. Toxicol Lett 2001;125:83-91. PubMed
  2. Yu, C., Shin, Y. G., Kosmeder, J. W., Pezzuto, J. M., and van Breemen, R. B. Liquid chromatography/tandem mass spectrometric determination of inhibition of human cytochrome P450 isozymes by resveratrol and resveratrol-3-sulfate. Rapid Commun.Mass Spectro PubMed
  3. Chachay VS, Macdonald GA, Martin JH, Whitehead JP, O'Moore-Sullivan TM, Lee P, Franklin M, Klein K, Taylor PJ, Ferguson M, Coombes JS, Thomas GP, Cowin GJ, Kirkpatrick CM, Prins JB, Hickman IJ. Resveratrol does not benefit patients with nonalcoholic fatty
Moderate

ESTROGENS

3 of 3

Ethinyl Estradiol, Norgestrel also falls under ESTROGENS.

Theoretically, hu zhang might competitively inhibit the effects of estrogen replacement therapy.
In vitro research shows that hu zhang might have estrogenic activity.
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 for your birth control pill (Ovral, Lo/Ovral, and similar). Hu Zhang is rich in resveratrol, and in lab dishes resveratrol can act a little like estrogen and also bump up against estrogen receptors. The thought is that it might compete with the ethinyl estradiol in your pill, in theory nudging your hormone activity in either direction. I want to be honest with you though: this is based only on test-tube and animal work, not real people, so it's quite uncertain.

Because reliable contraception matters, I wouldn't want to guess. If you take Hu Zhang regularly (not just an occasional culinary amount), check in with your pharmacist or doctor first. They can help you weigh it and watch for anything off, like breakthrough spotting or changes in your cycle.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Matsuda H, Shimoda H, Morikawa T, Yoshikawa M. Phytoestrogens from the roots of Polygonum cuspidatum (Polygonaceae): structure-requirement of hydroxyanthraquinones for estrogenic activity. Bioorg Med Chem Lett 2001;11:1839-42. PubMed
  2. Zhang CZ, Wang SX, Zhang Y, et al. In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms. J Ethnopharmacol 2005;98:295-300. 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

Hu Zhang Also Interacts With Other Medications

Hu Zhang has 825 moderate known drug interactions in our database — the Ethinyl Estradiol, Norgestrel one above is among them. If you take anything else, check it against the full list below.

Moderate 825 No known interaction 2,005 (incl. Ethinyl Estradiol, Norgestrel)
Taking anything else?

Check Another of Your Medications Against Hu Zhang

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

Everything else you take

See Every Supplement That Interacts With Ethinyl Estradiol, Norgestrel

This page covers Hu Zhang only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ethinyl Estradiol, Norgestrel 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, Norgestrel page

“With a birth control pill like ethinyl estradiol and norgestrel (Ovral, Lo/Ovral, Cryselle, Low-Ogestrel), a supplement interaction can mean an unplanned pregnancy rather than just a side effect, so the six major-rated entries among the 239 on this page deserve real attention before the rest. St.”

Reviewed by 2 · Jul 18, 2026

Open the Ethinyl Estradiol, Norgestrel interaction page

One more smart check

Taking Hu Zhang as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,014 real supplement products containing Hu Zhang, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hu Zhang. Your product may carry other ingredients that interact with Ethinyl Estradiol, Norgestrel too, on top of Hu Zhang — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Hu Zhang and Ethinyl Estradiol, Norgestrel 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 Hu Zhang
Top 25%

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

29 days ago today
Medication Ethinyl Estradiol, Norgestrel
Steady interest

#1,488 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 Hu Zhang

What is Hu Zhang?

  • Source of resveratrol
  • Heart and circulation support
  • Inflammation
  • Liver and digestive complaints (traditional)
  • Cough and respiratory symptoms (traditional)
  • Skin and joint conditions (traditional topical use)

Hu Zhang (Japanese knotweed root) is a traditional Chinese herb that is one of the richest natural sources of resveratrol and emodin. Some lab and early human research looks interesting for inflammation and heart health, but high-quality evidence in people is limited. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Hu Zhang monograph & all interactions
Keep checking

Other Drugs & Hu Zhang

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

0Major
825Moderate
0Minor
2,004No known interaction
825 Moderate 2,004 No interaction
Moderate

825 interactions

Showing 60 of 825 moderate interactions — see all 825 on the Hu Zhang page.

No interaction 2,004 drugs checked — show the list

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

Showing the 60 most looked-up of 2,004 medications checked with no known interaction — see the full Hu Zhang list.

See the full Hu Zhang interactions page
See every supplement checked against Ethinyl Estradiol, Norgestrel, 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
Hu Zhang monograph › Uses, safety, and every drug interaction in one place Ethinyl Estradiol, Norgestrel supplement interactions › Every supplement checked against Ethinyl Estradiol, Norgestrel, ranked by severity 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 Hu Zhang and Ethinyl Estradiol, Norgestrel Together: Common Questions

Can you take Hu Zhang with Ethinyl Estradiol, Norgestrel?
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 Hu Zhang and Ethinyl Estradiol, Norgestrel?
Ethinyl Estradiol, Norgestrel belongs to more than one drug category, and Hu Zhang 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 Hu Zhang and Ethinyl Estradiol, Norgestrel 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.