Drug & supplement interaction

Hemp + 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 Hemp can interact with; the most serious is rated moderate. Theoretically, hemp might interfere with hormone therapy due to its estrogenic effects.

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

Hemp and Conjugated Estrogens

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

Why Are There 2 Interactions?

Hemp interacts with whole categories of medication. Conjugated Estrogens falls into 2 of those categories, so it can interact with Hemp 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 Hemp interacts with.

Theoretically, hemp might interfere with hormone therapy due to its estrogenic effects.
In an ovariectomized animal model, a diet containing hemp seed 1%, 2%, or 10% resulted in normalized plasma levels of 17-beta-estradiol. The mechanism of action for this effect is unclear.
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 honest picture with hemp and Premarin (conjugated estrogens). The concern is that compounds in hemp may have mild estrogen-like activity of their own. In theory, that could nudge your overall hormone balance and slightly add to, or interfere with, what your prescribed estrogen is doing. In practice, this could mean shifts in symptoms like breast tenderness, bloating, spotting, or changes in how well your hot flashes stay controlled.

That said, this is weak, theory-based evidence from an animal study, not from people, and the actual mechanism isn't clear. Eating hemp seeds or hemp oil as food is very unlikely to cause trouble. Concentrated hemp supplements are more of a question mark. Before starting one, it's worth a quick chat with your pharmacist or doctor.

References
  1. Saberivand A, Karimi I, Becker LA, et al. The effects of Cannabis sativa L. seed (hempseed) in the ovariectomized rat model of menopause. Methods Find Exp Clin Pharmacol. 2010;32(7):467-73. PubMed
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

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

Theoretically, hemp might decrease the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that hemp induces CYP3A4 enzymes.
Severity Minor 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 basic idea. Your body uses a liver enzyme called CYP3A4 to help process conjugated estrogens (Premarin and similar). Lab studies suggest hemp may speed that enzyme up a bit, which in theory could clear estrogen out a little faster and slightly weaken its effect. In practice that might mean menopause symptoms like hot flashes, night sweats, or vaginal dryness creeping back, though this is far from certain.

I want to be honest about the strength of this one: it comes only from test-tube research, not real people, so it's rated minor and theoretical. Everyday hemp seeds or hemp oil in food are very unlikely to cause trouble. If you're using concentrated hemp supplements and notice your symptoms returning, just check in with your pharmacist or doctor before changing anything.

References
  1. Haron MH, Dale O, Martin K, et al. Evaluation of the Herb-Drug Interaction Potential of Commonly Used Botanicals on the US Market with Regard to PXR- and AhR-Mediated Influences on CYP3A4 and CYP1A2. J Diet Suppl 2022. 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

Hemp Also Interacts With Other Medications

Hemp has 40 moderate, 897 minor 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 Hemp

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

Everything else you take

See Every Supplement That Interacts With Conjugated Estrogens

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

We hold 720 real supplement products containing Hemp, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hemp. Your product may carry other ingredients that interact with Conjugated Estrogens too, on top of Hemp — 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 Hemp 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 Hemp
Top 25%

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

29 days ago today
Medication Conjugated Estrogens
Steady interest

#1,456 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 Hemp

What is Hemp?

Hemp
  • Plant-based protein source
  • Heart health support
  • Skin and hair health
  • Reducing inflammation
  • General nutrition (omega fatty acids)

Hemp seeds and hemp seed oil are nutritious foods rich in protein, fiber, and healthy omega-3 and omega-6 fatty acids, and they are generally safe for most people as part of the diet. While the nutrition is real, strong human evidence that hemp supplements treat specific medical conditions is limited. Talk with your pharmacist or doctor before using hemp products for a health concern, especially if you are pregnant or breastfeeding.

Read the full Hemp monograph & all interactions
Keep checking

Other Drugs & Hemp

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

0Major
40Moderate
897Minor
1,892No known interaction
Moderate

40 interactions

Minor

897 interactions

Showing 60 of 897 minor interactions — see all 897 on the Hemp page.

No interaction 1,892 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 Hemp and Conjugated Estrogens Together: Common Questions

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

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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.