Drug & supplement interaction

Chrysin + Ethinyl Estradiol, Norethindrone

Ethinyl Estradiol, Norethindrone brand names: Femhrt, Loestrin 21, Ovcon 35 21, Ovcon 50 28, Necon 0.5 35 21, and others.

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

Ethinyl Estradiol, Norethindrone falls into 3 drug categories that Chrysin can interact with; the most serious is rated moderate. Theoretically, chrysin might decrease the effects of estrogen therapy.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Chrysin and Ethinyl Estradiol, Norethindrone

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Chrysin interacts with whole categories of medication. Ethinyl Estradiol, Norethindrone falls into 3 of those categories, so it can interact with Chrysin in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ESTROGENS

1 of 3

Why this applies to Ethinyl Estradiol, Norethindrone

Ethinyl Estradiol, Norethindrone falls under ESTROGENS — the group Chrysin interacts with.

Theoretically, chrysin might decrease the effects of estrogen therapy.
In vitro research suggests that chrysin might have antiestrogenic activity.
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 medication pairs an estrogen (ethinyl estradiol) with a progestin (norethindrone), whether you take it for birth control or hormone therapy. Here's the concern with chrysin: in test-tube studies it can act against estrogen, both by blocking aromatase and by showing some anti-estrogen activity. In theory, that could nudge down the estrogen part of your pill and weaken what you're taking it for.

I want to be honest about how thin this evidence is. It comes only from lab and animal work, not from people, and chrysin is barely absorbed when swallowed, so a real-world effect is far from certain. Still, since steady hormone levels matter for things like reliable cycle control, it's worth a quick chat with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Han, D. H., Denison, M. S., Tachibana, H., and Yamada, K. Relationship between estrogen receptor-binding and estrogenic activities of environmental estrogens and suppression by flavonoids. Biosci.Biotechnol.Biochem 2002;66(7):1479-1487. PubMed
  2. Collins, B. M., McLachlan, J. A., and Arnold, S. F. The estrogenic and antiestrogenic activities of phytochemicals with the human estrogen receptor expressed in yeast. Steroids 1997;62(4):365-372. PubMed
  3. Kuiper, G. G., Lemmen, J. G., Carlsson, B., Corton, J. C., Safe, S. H., van der Saag, P. T., van der Burg, B., and Gustafsson, J. A. Interaction of estrogenic chemicals and phytoestrogens with estrogen receptor beta. Endocrinology 1998;139(10):4252-4263. PubMed
Moderate

CONTRACEPTIVE DRUGS

2 of 3

Ethinyl Estradiol, Norethindrone also falls under CONTRACEPTIVE DRUGS.

Theoretically, chrysin might reduce the efficacy of estrogen-containing contraceptive drugs.
In vitro research suggests that chrysin might have antiestrogenic activity.
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 for your birth control pill, which combines ethinyl estradiol (an estrogen) with norethindrone (a progestin). In test-tube studies, chrysin shows some anti-estrogen activity, meaning it may work against the estrogen part of your pill. The worry is that this could, in theory, weaken how well the pill prevents pregnancy. Keep in mind this is purely theoretical, based on lab research, not real people, and chrysin is barely absorbed by the body to begin with.

So I wouldn't lose sleep over it, but I also wouldn't gamble with an unproven supplement and your contraception. If you're considering chrysin, chat with your pharmacist or doctor first, and never adjust your pill on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Han, D. H., Denison, M. S., Tachibana, H., and Yamada, K. Relationship between estrogen receptor-binding and estrogenic activities of environmental estrogens and suppression by flavonoids. Biosci.Biotechnol.Biochem 2002;66(7):1479-1487. PubMed
  2. Collins, B. M., McLachlan, J. A., and Arnold, S. F. The estrogenic and antiestrogenic activities of phytochemicals with the human estrogen receptor expressed in yeast. Steroids 1997;62(4):365-372. PubMed
  3. Kuiper, G. G., Lemmen, J. G., Carlsson, B., Corton, J. C., Safe, S. H., van der Saag, P. T., van der Burg, B., and Gustafsson, J. A. Interaction of estrogenic chemicals and phytoestrogens with estrogen receptor beta. Endocrinology 1998;139(10):4252-4263. PubMed
Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

3 of 3

Ethinyl Estradiol, Norethindrone also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, chrysin might increase levels of drugs metabolized by CYP1A2.
In vitro research suggests that chrysin inhibits CYP1A2 isozymes. However, chrysin does not appear to inhibit CYP1A2-dependent caffeine metabolism in animals. Due to chrysin's low bioavailability and rapid metabolism to glucuronide and sulfate conjugates, this interaction is unlikely.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist for your birth control pill (the ethinyl estradiol and norethindrone combo): in test-tube studies, chrysin can slow down a liver enzyme called CYP1A2, which helps process the estrogen part. In theory, slowing that enzyme could let estrogen levels creep up a little, which might mean more of the usual estrogen-related side effects like nausea, breast tenderness, bloating, or headaches.

The good news is this is very much a paper concern. It's based only on lab work, not real people, and chrysin is barely absorbed by the body, so it's broken down fast. Animal studies didn't even show this effect. I wouldn't lose sleep over it, but since this pill matters for both your hormones and reliable contraception, run any chrysin supplement past your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Galijatovic A, Otake Y, Walle UK, Walle T. Extensive metabolism of the flavonoid chrysin by human Caco-2 and Hep G2 cells. Xenobiotica 1999;29:1241-56. PubMed
  2. Lee H, Yeom H, Kim YG, et al. Structure-related inhibition of human hepatic caffeine N3-demethylation by naturally occurring flavonoids. Biochem Pharmacol 1998;55:1369-75. PubMed
  3. Galijatovic A, Walle UK, Walle T. Induction of UDP-glucuronosyltransferase by the flavonoids chrysin and quercetin in Caco-2 cells. Pharm Res 2000;17:21-6.
  4. Walle UK, Galijatovic A, Walle T. Transport of the flavonoid chrysin and its conjugated metabolites by the human intestinal cell line Caco-2. Biochem Pharmacol 1999;58:431-8. PubMed
  5. Walle T, Otake Y, Brubaker JA, et al. Disposition and metabolism of the flavonoid chrysin in normal volunteers. Br J Clin Pharmacol 2001;51:143-6. DOI
  6. Lautraite S, Musonda AC, Doehmer J, et al. Flavonoids inhibit genetic toxicity produced by carcinogens in cells expressing CYP1A2 and CYP1A1. Mutagenesis 2002;17:45-53. PubMed
  7. Simons, A. L., Renouf, M., Hendrich, S., and Murphy, P. A. Human gut microbial degradation of flavonoids: structure-function relationships. J Agric.Food Chem 5-18-2005;53(10):4258-4263. PubMed
  8. Kim, H. J., Lee, S. B., Park, S. K., Kim, H. M., Park, Y. I., and Dong, M. S. Effects of hydroxyl group numbers on the B-ring of 5,7-dihydroxyflavones on the differential inhibition of human CYP 1A and CYP1B1 enzymes. Arch Pharm Res 2005;28(10):1114-1121 PubMed
  9. Moon, Y. J., Wang, X., and Morris, M. E. Dietary flavonoids: effects on xenobiotic and carcinogen metabolism. Toxicol In Vitro 2006;20(2):187-210. PubMed
  10. Tsyrlov, I. B., Mikhailenko, V. M., and Gelboin, H. V. Isozyme- and species-specific susceptibility of cDNA-expressed CYP1A P-450s to different flavonoids. Biochim.Biophys Acta 4-13-1994;1205(2):325-335. PubMed
  11. Noh K, Oh do G, Nepal MR, et al. Pharmacokinetic interaction of chrysin with caffeine in rats. Biomol Ther (Seoul) 2016;24(4):446-52. 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

Chrysin Also Interacts With Other Medications

Chrysin has 178 moderate, 179 minor known drug interactions in our database — the Ethinyl Estradiol, Norethindrone one above is among them. If you take anything else, check it against the full list below.

Moderate 178 Minor 179 No known interaction 2,473 (incl. Ethinyl Estradiol, Norethindrone)
Taking anything else?

Check Another of Your Medications Against Chrysin

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

Everything else you take

See Every Supplement That Interacts With Ethinyl Estradiol, Norethindrone

This page covers Chrysin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ethinyl Estradiol, Norethindrone page lists 240 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 · 196 moderate · 38 minor.

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

“If you take a birth control pill or hormone therapy containing ethinyl estradiol and norethindrone (Loestrin, Femhrt, and others), a few supplements can genuinely undermine it, so read this page with care. Six of the 240 ingredients on file are rated major, and those six come first.”

Reviewed by 2 · Jul 18, 2026

Open the Ethinyl Estradiol, Norethindrone interaction page

One more smart check

Taking Chrysin as Part of a Dietary Supplement Product? Check It for Interactions

We hold 272 real supplement products containing Chrysin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chrysin. Your product may carry other ingredients that interact with Ethinyl Estradiol, Norethindrone too, on top of Chrysin — 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 Chrysin and Ethinyl Estradiol, Norethindrone 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 Chrysin
Top 25%

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

29 days ago today
Medication Ethinyl Estradiol, Norethindrone
Top 25%

#355 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 Chrysin

What is Chrysin?

  • Bodybuilding and testosterone support
  • Anxiety and stress
  • Anti-inflammatory
  • Antioxidant support
  • Prostate health

Chrysin is a plant flavonoid sold mainly as a bodybuilding supplement claimed to raise testosterone or block estrogen, but human studies have not shown these benefits, largely because the body absorbs very little of it. Evidence for its other proposed uses is mostly limited to laboratory and animal research, so its real-world value is unclear. Talk with your pharmacist or doctor before using it.

Read the full Chrysin monograph & all interactions
Keep checking

Other Drugs & Chrysin

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

0Major
178Moderate
179Minor
2,472No known interaction
178 Moderate 179 Minor 2,472 No interaction
Moderate

178 interactions

Showing 60 of 178 moderate interactions — see all 178 on the Chrysin page.

Minor

179 interactions

Showing 60 of 179 minor interactions — see all 179 on the Chrysin page.

No interaction 2,472 drugs checked — show the list

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

Showing the 60 most looked-up of 2,472 medications checked with no known interaction — see the full Chrysin list.

See the full Chrysin interactions page
See every supplement checked against Ethinyl Estradiol, Norethindrone, 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
Chrysin monograph › Uses, safety, and every drug interaction in one place Ethinyl Estradiol, Norethindrone supplement interactions › Every supplement checked against Ethinyl Estradiol, Norethindrone, 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 Chrysin and Ethinyl Estradiol, Norethindrone Together: Common Questions

Can you take Chrysin with Ethinyl Estradiol, Norethindrone?
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 3 interactions listed for Chrysin and Ethinyl Estradiol, Norethindrone?
Ethinyl Estradiol, Norethindrone belongs to more than one drug category, and Chrysin 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 Chrysin and Ethinyl Estradiol, Norethindrone 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.