Drug & supplement interaction

Equol + Ethinyl Estradiol, Drospirenone

Ethinyl Estradiol, Drospirenone brand name: Yaz.

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

Ethinyl Estradiol, Drospirenone 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 Ethinyl Estradiol, Drospirenone

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. Ethinyl Estradiol, Drospirenone 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 Ethinyl Estradiol, Drospirenone

Ethinyl Estradiol, Drospirenone 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

If you take Yaz (which combines ethinyl estradiol with drospirenone), here's what equol might do. In a test tube, equol seems to bump estrogen off the proteins that carry it through your blood. The idea is that this could leave a little more 'free' ethinyl estradiol floating around and active. In plain terms, your body might feel slightly more estrogen effect than usual.

What that could look like: more headaches, sore or tender breasts, cramping, or some water weight gain. I want to be honest though, this is theoretical and based only on lab research, not real people, so it may not amount to much. It won't make your pill stop working. Still, it's worth a quick chat with your pharmacist or doctor before adding an equol supplement.

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

Ethinyl Estradiol, Drospirenone 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

Here's the gist with Yaz (which combines ethinyl estradiol and drospirenone) and equol. Equol gently acts like estrogen in the body, and in lab studies it loosened estrogen from the proteins that normally carry it in your blood. The theory is that this could leave a little more free, active estrogen floating around, which might slightly nudge up estrogen-type side effects from your pill.

In real life that could look like more breast tenderness, headaches, bloating, nausea, or mood changes. I want to be honest though: this is based only on test-tube work, not on people, so it's far from proven. It won't change how well Yaz prevents pregnancy. Still, since you're on a daily hormone, it's worth a quick chat with your pharmacist or doctor before adding equol, and skip it altogether if you're pregnant or breastfeeding.

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 Ethinyl Estradiol, Drospirenone 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. Ethinyl Estradiol, Drospirenone)
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 Ethinyl Estradiol, Drospirenone

This page covers Equol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ethinyl Estradiol, Drospirenone page lists 245 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 6 major · 200 moderate · 39 minor.

Open the Ethinyl Estradiol, Drospirenone interaction page

How much people look this up

Where Equol and Ethinyl Estradiol, Drospirenone 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

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

29 days ago today
Medication Ethinyl Estradiol, Drospirenone
Top 5%

#116 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 Ethinyl Estradiol, Drospirenone, 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 Ethinyl Estradiol, Drospirenone supplement interactions › Every supplement checked against Ethinyl Estradiol, Drospirenone, 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 Ethinyl Estradiol, Drospirenone Together: Common Questions

Can you take Equol with Ethinyl Estradiol, Drospirenone?
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 Ethinyl Estradiol, Drospirenone?
Ethinyl Estradiol, Drospirenone 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 Ethinyl Estradiol, Drospirenone 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.