Drug & supplement interaction

Hu Zhang + Estropipate

Estropipate brand names: Ogen, Ortho EST.

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

Hu Zhang has a moderate interaction with Estropipate. Theoretically, hu zhang might competitively inhibit the effects of estrogen replacement therapy.

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

Hu Zhang and Estropipate

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

Moderate

ESTROGENS

Why this applies to Estropipate

Estropipate falls under ESTROGENS — the group Hu Zhang interacts with.

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 idea behind this one. Estropipate is a form of estrogen you take to ease menopause symptoms like hot flashes and vaginal dryness, or to help protect your bones. Hu Zhang is rich in resveratrol, which in lab dishes can act a little like a weak estrogen and may bump up against estrogen receptors. The theory is that Hu Zhang could compete with your estropipate and slightly blunt how well it works.

I want to be honest about the strength of this, though. This concern comes only from test tube and animal research, not from real people, so it's quite theoretical and nothing to panic over. Still, if you notice your hot flashes or dryness creeping back while using Hu Zhang, mention it to your pharmacist or doctor before changing anything.

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 Estropipate one above is one of them. If you take anything else, check it against the full list below.

Moderate 825 No known interaction 2,005 (incl. Estropipate)
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.

From our Q&A

Questions About Hu Zhang or Estropipate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Hu Zhang or Estropipate, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Estropipate

This page covers Hu Zhang only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Estropipate page lists 77 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Aletris (moderate), Alfalfa (moderate) and Androstenediol (moderate).

By severity: 2 major · 61 moderate · 14 minor.

From our pharmacist’s overview on the Estropipate page

“Estropipate (Ogen, Ortho EST) is an estrogen taken for menopause symptoms, and the women who use it are drawn to hormone-touted herbs, which fill this list of 77 ingredients, so it deserves genuine care. Grapefruit is one of two major-rated entries; it blocks the enzyme that clears estrogen, so levels and side effects can climb.”

Reviewed by 2 · Jul 18, 2026

Open the Estropipate 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 Estropipate 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 Estropipate 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%

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

29 days ago today
Medication Estropipate
Steady interest

#2,075 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
Medication

About Estrogen

What Is Estrogen Used For?

Brand names: Ogen, Ortho EST

Based on the available product information, this Estrogen product is intended for external use on the skin — specifically the face, neck, or body. It is applied as part of a daily skincare routine.

For any specific medical concerns, the label recommends consulting a healthcare provider before use.

See full Estrogen drug information
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 Estropipate, 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 Estropipate supplement interactions › Every supplement checked against Estropipate, ranked by severity Estrogen 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 Hu Zhang and Estropipate Together: Common Questions

Can you take Hu Zhang with Estropipate?
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 Hu Zhang and Estropipate 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 Estropipate and Hu Zhang?

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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.