Drug & supplement interaction

Equol + Relugolix, Estradiol, Norethindrone Acetate

Relugolix, Estradiol, Norethindrone Acetate brand name: Myfembree.

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

Equol has a moderate interaction with Relugolix, Estradiol, Norethindrone Acetate. Theoretically, equol might increase the levels and clinical effects of estrogens.

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

Equol and Relugolix, Estradiol, Norethindrone Acetate

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

Moderate

ESTROGENS

Why this applies to Relugolix, Estradiol, Norethindrone Acetate

Relugolix, Estradiol, Norethindrone Acetate falls under ESTROGENS — the group Equol interacts with.

Theoretically, equol might increase the levels and clinical effects of estrogens.
In vitro research shows that equol inhibits the binding of estradiol to serum proteins. Theoretically, this might increase the concentration of free, bioactive estradiol, thereby increasing the risk of adverse effects from estrogen replacement therapy, including headaches, breast tenderness, and weight gain.
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

Myfembree contains estradiol, a form of estrogen, combined with relugolix and norethindrone. Here is the idea behind this interaction: in a lab setting, equol seemed to bump estradiol off the blood proteins that normally carry it around. If that happened in your body, a little more free estradiol could float around and act more strongly. With Myfembree, that might show up as slightly more estrogen-type effects, like headaches, breast tenderness, bloating, nausea, or weight changes.

I want to be honest about how weak this evidence is. It comes only from test-tube research, not from people, so it's mostly theoretical. Still, since you're already getting hormones in this pill, it's worth a quick chat with your pharmacist or doctor before adding equol rather than guessing.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Martin ME, Haouriqui M, Pelissero C, et al. Interactions between phytoestrogens and human sex steroid binding protein. Life Sci 1996;58:429-36. 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

Equol Also Interacts With Other Medications

Equol has 57 moderate, 75 minor known drug interactions in our database — the Relugolix, Estradiol, Norethindrone Acetate one above is one of them. If you take anything else, check it against the full list below.

Moderate 57 Minor 75 No known interaction 2,698 (incl. Relugolix, Estradiol, Norethindrone Acetate)
Taking anything else?

Check Another of Your Medications Against Equol

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

Everything else you take

See Every Supplement That Interacts With Relugolix, Estradiol, Norethindrone Acetate

This page covers Equol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Relugolix, Estradiol, Norethindrone Acetate page lists 219 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 8 major · 174 moderate · 37 minor.

From our pharmacist’s overview on the Relugolix, Estradiol, Norethindrone Acetate page

“Grapefruit is where I would start on this page. Myfembree (relugolix, estradiol, and norethindrone acetate) depends on the CYP3A4 enzyme to be cleared, and grapefruit juice blocks that enzyme, raising drug levels and side effect risk.”

Reviewed by 2 · Jul 18, 2026

Open the Relugolix, Estradiol, Norethindrone Acetate interaction page

How much people look this up

Where Equol and Relugolix, Estradiol, Norethindrone Acetate 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 Equol
Steady interest

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

29 days ago today
Medication Relugolix, Estradiol, Norethindrone Acetate
Steady interest

#2,052 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 Equol

What is Equol?

  • Menopause symptoms (hot flashes)
  • Bone health support
  • Skin aging
  • Prostate health
  • General hormone balance

Equol is a compound made in the gut when some people break down soy isoflavones, and it is also sold as a supplement. Early research links it to possible benefits for menopause symptoms and bone or skin health, but the evidence is still limited and far from proven. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Equol monograph & all interactions
Medication

About Relugolix, Estradiol, and Norethindrone

What Is Relugolix, Estradiol, and Norethindrone Used For?

Brand name: Myfembree

Myfembree is approved for two conditions in premenopausal women: managing heavy menstrual bleeding caused by uterine fibroids (non-cancerous growths in the uterus), and managing moderate to severe pain caused by endometriosis (a condition where tissue similar to the uterine lining grows outside the uterus).

Treatment with Myfembree should not exceed 24 months because of the risk of ongoing bone loss that may not fully reverse after stopping the medication.

See full Relugolix, Estradiol, and Norethindrone drug information
Keep checking

Other Drugs & Equol

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

0Major
57Moderate
75Minor
2,697No known interaction
57 Moderate 75 Minor 2,697 No interaction
Moderate

57 interactions

Minor

75 interactions

Showing 60 of 75 minor interactions — see all 75 on the Equol page.

No interaction 2,697 drugs checked — show the list

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

Showing the 60 most looked-up of 2,697 medications checked with no known interaction — see the full Equol list.

See the full Equol interactions page
See every supplement checked against Relugolix, Estradiol, Norethindrone Acetate, 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
Equol monograph › Uses, safety, and every drug interaction in one place Relugolix, Estradiol, Norethindrone Acetate supplement interactions › Every supplement checked against Relugolix, Estradiol, Norethindrone Acetate, ranked by severity Relugolix, Estradiol, and Norethindrone 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 Equol and Relugolix, Estradiol, Norethindrone Acetate Together: Common Questions

Can you take Equol with Relugolix, Estradiol, Norethindrone Acetate?
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 Equol and Relugolix, Estradiol, Norethindrone Acetate 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 Relugolix, Estradiol, Norethindrone Acetate and Equol?

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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.