Drug & supplement interaction

Pregnenolone + Conjugated Estrogens

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

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

Pregnenolone has a moderate interaction with Conjugated Estrogens. Theoretically, taking pregnenolone might enhance the effects of estrogens.

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

Pregnenolone 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 Pregnenolone interacts with.

Theoretically, taking pregnenolone might enhance the effects of estrogens.
Pregnenolone is a precursor for several steroid hormones, including estrogens.
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 basic idea: pregnenolone sits near the top of your body's hormone assembly line, and your body can turn it into other steroid hormones, including estrogens. So on paper, layering pregnenolone on top of a medication like Premarin could add a little extra estrogen activity to what you're already getting.

If that happened, you might notice more of the usual estrogen-related effects, like breast tenderness, bloating, nausea, headaches, or spotting. I want to be straight with you, though: this is a theoretical concern based on how these hormones work, not something proven in studies. Still, since you're already taking a prescribed estrogen, it's worth a quick chat with your pharmacist or doctor before adding pregnenolone rather than starting it on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Devlin TM, ed. Textbook of Biochemistry With Clinical Correlations. third ed. New York: Wiley-Liss Inc., 1992.

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

Pregnenolone Also Interacts With Other Medications

Pregnenolone has 81 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.

Moderate 81 No known interaction 2,749 (incl. Conjugated Estrogens)
Taking anything else?

Check Another of Your Medications Against Pregnenolone

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

Everything else you take

See Every Supplement That Interacts With Conjugated Estrogens

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

We hold 303 real supplement products containing Pregnenolone, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Pregnenolone. Your product may carry other ingredients that interact with Conjugated Estrogens too, on top of Pregnenolone — 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 Pregnenolone 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 Pregnenolone
Top 25%

#321 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 Pregnenolone

What is Pregnenolone?

Pregnenolone
  • Memory and cognitive support
  • Anxiety and stress
  • Anti-aging
  • Fatigue and low energy
  • Mood support

Pregnenolone is a hormone your body makes naturally and a building block for other hormones like cortisol, DHEA, estrogen, and testosterone. It is sold as a supplement for memory, mood, and anti-aging, but solid human evidence for these uses is very limited. Because it is a hormone, talk with your pharmacist or doctor before using it.

Read the full Pregnenolone monograph & all interactions
Keep checking

Other Drugs & Pregnenolone

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

0Major
81Moderate
0Minor
2,748No known interaction
81 Moderate 2,748 No interaction
Moderate

81 interactions

Showing 60 of 81 moderate interactions — see all 81 on the Pregnenolone page.

No interaction 2,748 drugs checked — show the list

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

Showing the 60 most looked-up of 2,748 medications checked with no known interaction — see the full Pregnenolone list.

See the full Pregnenolone 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
Pregnenolone 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 Pregnenolone and Conjugated Estrogens Together: Common Questions

Can you take Pregnenolone 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 Pregnenolone 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 Pregnenolone?

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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.