Drug & supplement interaction

Equol + Segesterone Acetate, Ethinyl Estradiol

Segesterone Acetate, Ethinyl Estradiol brand name: Annovera.

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

Segesterone Acetate, Ethinyl Estradiol falls into 2 drug categories that Equol can interact with; the most serious is rated moderate. Theoretically, equol might increase the levels and clinical effects of ethinyl estradiol found in contraceptive drugs.

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

Equol and Segesterone Acetate, Ethinyl Estradiol

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

Why Are There 2 Interactions?

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

Moderate

CONTRACEPTIVE DRUGS

1 of 2

Why this applies to Segesterone Acetate, Ethinyl Estradiol

Segesterone Acetate, Ethinyl Estradiol falls under CONTRACEPTIVE DRUGS — the group Equol interacts with.

Theoretically, equol might increase the levels and clinical effects of ethinyl estradiol found in contraceptive drugs.
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 ethinyl estradiol, including headaches, breast tenderness, dysmenorrhea, 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

Your Annovera ring releases two hormones, including ethinyl estradiol (a form of estrogen). Equol is a soy-based phytoestrogen, and here's the theory: in lab studies, equol nudges estrogen off the proteins that normally hold it in your bloodstream. If that happened in your body, more free, active estrogen could circulate, which could turn up the usual estrogen-related side effects.

For you, that might mean things like headaches, breast tenderness, painful periods, or some weight changes. I want to be honest, though: this is only test-tube research, not real-world proof, so it may not amount to much. Still, it's worth a quick chat with your pharmacist or doctor before adding equol, and let them know if any of those symptoms pop up.

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
Moderate

ESTROGENS

2 of 2

Segesterone Acetate, Ethinyl Estradiol also falls under ESTROGENS.

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

Annovera is a vaginal ring that releases two hormones, segesterone acetate (a progestin) and ethinyl estradiol (an estrogen). The concern here is with the estrogen part. In a test tube, equol seems to nudge estradiol off the proteins that normally hold it in your blood. The idea is that more of the estrogen could float around freely and act more strongly. If that happened, you might notice more of the usual estrogen-type effects, like headaches, sore or tender breasts, bloating, or some weight changes.

I want to be straight with you though: this is purely a lab-based, theoretical concern, not something proven in people. It's likely minor for most folks. Still, since you're using hormones daily, it's worth a quick chat with your pharmacist or doctor before adding equol.

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 Segesterone Acetate, Ethinyl Estradiol one above is among them. If you take anything else, check it against the full list below.

Moderate 57 Minor 75 No known interaction 2,698 (incl. Segesterone Acetate, Ethinyl Estradiol)
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 Segesterone Acetate, Ethinyl Estradiol

This page covers Equol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Segesterone Acetate, Ethinyl Estradiol page lists 229 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Grapefruit (major), Siberian Cocklebur (major), St. John's Wort (major) and Wine (major).

By severity: 5 major · 193 moderate · 31 minor.

From our pharmacist’s overview on the Segesterone Acetate, Ethinyl Estradiol page

“St. John's wort is the interaction I would explain first to anyone using Annovera (segesterone acetate with ethinyl estradiol, a vaginal ring for birth control).”

Reviewed by 2 · Jul 18, 2026

Open the Segesterone Acetate, Ethinyl Estradiol interaction page

How much people look this up

Where Equol and Segesterone Acetate, Ethinyl Estradiol 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 Segesterone Acetate, Ethinyl Estradiol
Steady interest

#1,956 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
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 Segesterone Acetate, Ethinyl Estradiol, 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 Segesterone Acetate, Ethinyl Estradiol supplement interactions › Every supplement checked against Segesterone Acetate, Ethinyl Estradiol, 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 Equol and Segesterone Acetate, Ethinyl Estradiol Together: Common Questions

Can you take Equol with Segesterone Acetate, Ethinyl Estradiol?
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 Equol and Segesterone Acetate, Ethinyl Estradiol?
Segesterone Acetate, Ethinyl Estradiol belongs to more than one drug category, and Equol 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 Equol and Segesterone Acetate, Ethinyl Estradiol 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

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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.