Drug & supplement interaction

Peony + Conjugated Estrogens

Conjugated Estrogens brand names: Premarin, Cenestin, Enjuvia, Premarin Vaginal Cream.

Moderate Interaction
The bottom line Moderate

Conjugated Estrogens falls into 2 drug categories that Peony can interact with; the most serious is rated moderate. Theoretically, concomitant use of large amounts of peony might interfere with hormone replacement therapy and/or increase the risk for estrogen-related adverse effects.

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

Peony and Conjugated Estrogens

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

Why Are There 2 Interactions?

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

Moderate

ESTROGENS

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Why this applies to Conjugated Estrogens

Conjugated Estrogens falls under ESTROGENS — the group Peony interacts with.

Theoretically, concomitant use of large amounts of peony might interfere with hormone replacement therapy and/or increase the risk for estrogen-related adverse effects.
In vitro and animal research shows that peony extract has estrogenic activity. Theoretically, peony might compete for estrogen receptors and/or cause additive estrogenic effects.
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 Premarin and similar conjugated estrogen products. Lab and animal studies suggest peony root may act a little like estrogen in the body, possibly latching onto the same receptors your hormone therapy works on. In theory, taking concentrated peony supplements alongside your estrogen could either add to estrogen effects or compete with them. If effects add up, you might notice more of the usual estrogen-related issues like breast tenderness, bloating, nausea, or spotting.

Keep in mind this is a theoretical concern only, based on test-tube and animal data, not real patient cases. Occasional culinary or small amounts are unlikely to matter much. Before starting concentrated peony supplements, just run it by your pharmacist or doctor so they can keep an eye on things.

References
  1. Xu Y, Li X, Chen T, et al. Radix Paeoniae Alba increases serum estrogen level and up-regulates estrogen receptor expression in uterus and vagina of immature/ovariectomized mice. Phytother Res. 2019;33(1):117-29. [RETRACTED].
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

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

Theoretically, use of peony may increase the levels and clinical effects of drugs metabolized by CYP3A4.
In vitro research shows that peony suppresses the metabolism of clozapine via weak-to-moderate inhibitory effects on CYP1A2 and CYP3A4. This effect 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 partly clears conjugated estrogens (Premarin and similar) through a liver enzyme called CYP3A4. In lab and animal studies, peony seems to gently slow that same enzyme down. If that held true in people, it could mean a bit more estrogen lingering in your system, which might nudge up side effects like breast tenderness, bloating, nausea, headaches, or spotting.

The important caveat: this is theoretical. It has only been seen in test tubes and animals, never confirmed in real patients, and the effect looked weak. So I wouldn't lose sleep over it. Still, since estrogen therapy is something we like to keep steady, it's worth a quick chat with your pharmacist or doctor before adding a peony supplement, especially concentrated capsules rather than tiny culinary amounts.

References
  1. Wang W, Tian DD, Zheng B, et al. Peony-glycyrrhiza decoction, an herbal preparation, inhibits clozapine metabolism via cytochrome P450s, but not flavin-containing monooxygenase in in vitro models. Drug Metab Dispos 2015;43(7):1147-53. 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

Peony Also Interacts With Other Medications

Peony has 810 moderate known drug interactions in our database — the Conjugated Estrogens 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 Peony

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

Everything else you take

See Every Supplement That Interacts With Conjugated Estrogens

This page covers Peony only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Conjugated Estrogens page lists 207 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), Tiratricol (major) and Acacia Rigidula (moderate).

By severity: 4 major · 172 moderate · 31 minor.

From our pharmacist’s overview on the Conjugated Estrogens page

“Conjugated estrogens (Premarin, Cenestin) are hormone replacement, most often for menopause symptoms, and the 207 supplements here warrant real care before adding any of them. Most of the risk runs through drug processing: 121 entries involve the CYP3A4 enzyme that clears estrogen, which is how St.”

Reviewed by 2 · Jul 18, 2026

Open the Conjugated Estrogens interaction page

One more smart check

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

We hold 71 real supplement products containing Peony, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Peony. Your product may carry other ingredients that interact with Conjugated Estrogens too, on top of Peony — 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 Peony and Conjugated Estrogens 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 Peony
Top 25%

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

29 days ago today
Medication Conjugated Estrogens
Top 25%

#566 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 Peony

What is Peony?

Peony
  • Menstrual cramps and irregular periods
  • Muscle cramps and spasms
  • Anxiety and stress
  • Inflammation and pain
  • Polycystic ovary syndrome (PCOS)

Peony root is a traditional Chinese medicine herb often used for menstrual problems, cramps, and inflammation, frequently as part of combination formulas. Human evidence for most uses is limited or preliminary, so it should not replace proven treatments. Talk to your pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or taking other medicines.

Read the full Peony monograph & all interactions
Keep checking

Other Drugs & Peony

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

0Major
810Moderate
0Minor
2,019No known interaction
Moderate

810 interactions

Showing 60 of 810 moderate interactions — see all 810 on the Peony page.

No interaction 2,019 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 Peony and Conjugated Estrogens Together: Common Questions

Can you take Peony with Conjugated Estrogens?
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 Peony and Conjugated Estrogens?
Conjugated Estrogens belongs to more than one drug category, and Peony 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 Peony and Conjugated Estrogens 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 Conjugated Estrogens and Peony?

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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.