Drug & supplement interaction

Dong Quai + Conjugated Estrogens

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

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

Dong Quai has a moderate interaction with Conjugated Estrogens. Theoretically, dong quai may reduce the effects of estrogens.

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

Dong Quai and Conjugated Estrogens

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

Moderate

ESTROGENS

Why this applies to Conjugated Estrogens

Conjugated Estrogens falls under ESTROGENS — the group Dong Quai interacts with.

Theoretically, dong quai may reduce the effects of estrogens.
Dong quai has estrogenic effects. Theoretically, concomitant use of large amounts of dong quai might interfere with hormone replacement therapy due to competition for estrogen receptors.
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

If you're taking Premarin or another conjugated estrogen for menopause symptoms, here's the idea behind this one. Some compounds in Dong Quai are thought to act a little like estrogen and may compete for the same spots (estrogen receptors) that your medication works on. In theory, taking large amounts of Dong Quai could blunt how well your estrogen therapy works, which might mean your hot flashes, vaginal dryness, or other symptoms aren't as well controlled.

I want to be honest though: this concern comes only from lab and animal research, and human studies haven't clearly shown Dong Quai acts like estrogen at all. So it's a theoretical caution, not a proven problem. Still, since both touch on hormones (and Dong Quai can affect bleeding), it's worth a quick chat with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Eagon PK, Elm MS, Hunter DS, et al. Medicinal herbs: modulation of estrogen action. Era of Hope Mtg, Dept Defense; Breast Cancer Res Prog, Atlanta, GA 2000;Jun 8-11.
  2. Amato P, Christophe S, Mellon PL. Estrogenic activity of herbs commonly used as remedies for menopausal symptoms. Menopause 2002;9:145-50. PubMed
  3. Chang CJ, Chiu JH, Tseng LM, et al. Modulation of HER2 expression by ferulic acid on human breast cancer MCF7 cells. Eur J Clin Invest 2006;36:588-96. PubMed
  4. Lau CBS, Ho TCY, Chan TWL, Kim SCF. Use of dong quai (Angelica sinensis) to treat peri- and postmenopausal symptoms in women with breast cancer: is it appropriate? Menopause 2005;12:734-40.
  5. Circosta, C., Pasquale, R. D., Palumbo, D. R., Samperi, S., and Occhiuto, F. Estrogenic activity of standardized extract of Angelica sinensis. Phytother.Res. 2006;20(8):665-669.

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

Dong Quai Also Interacts With Other Medications

Dong Quai has 2 major, 160 moderate known drug interactions in our database — the Conjugated Estrogens one above is one of them. If you take anything else, check it against the full list below.

Major 2 Moderate 160 No known interaction 2,668 (incl. Conjugated Estrogens)
Taking anything else?

Check Another of Your Medications Against Dong Quai

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

Everything else you take

See Every Supplement That Interacts With Conjugated Estrogens

This page covers Dong Quai 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 Dong Quai as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,989 real supplement products containing Dong Quai, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Dong Quai. Your product may carry other ingredients that interact with Conjugated Estrogens too, on top of Dong Quai — 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 Dong Quai 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 Dong Quai
Top 10%

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

29 days ago today
Medication Conjugated Estrogens
Steady interest

#1,486 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 Dong Quai

What is Dong Quai?

Dong Quai
  • Menopause symptoms
  • Menstrual cramps and irregular periods
  • Premenstrual syndrome (PMS)
  • Blood circulation support
  • General women's health tonic

Dong Quai is a traditional Chinese herb often called "female ginseng" and is mostly used for menstrual and menopausal complaints. High-quality scientific evidence that it works for these uses is limited, and it can affect bleeding, so talk with your pharmacist or doctor before trying it.

Read the full Dong Quai monograph & all interactions
Keep checking

Other Drugs & Dong Quai

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

2Major
160Moderate
0Minor
2,667No known interaction
2 Major 160 Moderate 2,667 No interaction
Major

2 interactions

Moderate

160 interactions

Showing 60 of 160 moderate interactions — see all 160 on the Dong Quai page.

No interaction 2,667 drugs checked — show the list

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

Showing the 60 most looked-up of 2,667 medications checked with no known interaction — see the full Dong Quai list.

See the full Dong Quai interactions page
See every supplement checked against Conjugated Estrogens, 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
Dong Quai monograph › Uses, safety, and every drug interaction in one place Conjugated Estrogens supplement interactions › Every supplement checked against Conjugated Estrogens, 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 Dong Quai and Conjugated Estrogens Together: Common Questions

Can you take Dong Quai 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.
How serious is the Dong Quai 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 Dong Quai?

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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.