Drug & supplement interaction

Pu-erh Tea + 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 Pu-erh Tea can interact with; the most serious is rated moderate. Theoretically, concomitant use might increase the levels and adverse effects of caffeine.

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

Pu-erh Tea and Ethinyl Estradiol, Norethindrone

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

Why Are There 3 Interactions?

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

Moderate

CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS

1 of 3

Why this applies to Ethinyl Estradiol, Norethindrone

Ethinyl Estradiol, Norethindrone falls under CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS — the group Pu-erh Tea interacts with.

Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Pu-erh tea contains caffeine. Caffeine is metabolized by CYP1A2. Theoretically, drugs that inhibit CYP1A2 may decrease the clearance rate of caffeine from pu-erh tea and increase caffeine levels.
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 a twist worth knowing: with this combo, your birth control pill (the ethinyl estradiol part) is actually the player that can slow down caffeine. Estrogen-containing pills gently block an enzyme called CYP1A2, which is the same enzyme that breaks down the caffeine in your pu-erh tea. So the tea isn't acting on your medication. Instead, your pill can make caffeine linger longer in your body.

In real life, that might mean your usual cup or two of pu-erh hits a little harder: think jitteriness, a racing heart, trouble sleeping, or feeling wired. This is a theoretical, mild concern, not something that hurts how well your pill works. If caffeine seems to bother you more than before, just ease back on it and mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Weisburger JH. Tea and health: the underlying mechanisms. Proc Soc Exp Biol Med 1999;220:271-5. PubMed
  2. Hagg S, Spigset O, Mjorndal T, Dahlqvist R. Effect of caffeine on clozapine pharmacokinetics in healthy volunteers. Br J Clin Pharmacol 2000;49:59-63. PubMed
  3. Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin Pharmacokinet 2000;39:127-53. PubMed
  4. Kot, M. and Daniel, W. A. Effect of diethyldithiocarbamate (DDC) and ticlopidine on CYP1A2 activity and caffeine metabolism: an in vitro comparative study with human cDNA-expressed CYP1A2 and liver microsomes. Pharmacol Rep. 2009;61(6):1216-1220. PubMed
  5. Wojcikowski, J. and Daniel, W. A. Perazine at therapeutic drug concentrations inhibits human cytochrome P450 isoenzyme 1A2 (CYP1A2) and caffeine metabolism--an in vitro study. Pharmacol Rep. 2009;61(5):851-858. PubMed
  6. Wang, X. and Yeung, J. H. Effects of the aqueous extract from Salvia miltiorrhiza Bunge on caffeine pharmacokinetics and liver microsomal CYP1A2 activity in humans and rats. J Pharm Pharmacol 2010;62(8):1077-1083.
  7. Kot M, Daniel WA. Caffeine as a marker substrate for testing cytochrome P450 activity in human and rat. Pharmacol Rep 2008;60:789-97.
  8. Kjaerstad MB, Nielsen F, Nohr-Jensen L, et al. Systemic uptake of miconazole during vaginal suppository use and effect on CYP1A2 and CYP3A4 associated enzyme activities in women. Eur J Clin Pharmacol 2010;66:1189-97. PubMed
  9. Goh BC, Reddy NJ, Dandamudi UB, et al. An evaluation of the drug interaction potential of pazopanib, an oral vascular endothelial growth factor receptor tyrosine kinase inhibitor, using a modified Cooperstown 5+1 cocktail in patients with advanced solid t
  10. Chen Y, Kang Z, Yan J, et al. Liu wei di huang wan, a well-known traditional Chinese medicine induces CYP1A2 while suppressing CYP2A6 and N-acetyltransferase 2 acivities in man. J Ethnopharmacol 2010;132:213-8.
  11. Suzuki S, Murayama Y, Sugiyama E, et al. Estimating pediatric doses of drugs metabolized by cytochrome P450 (CYP) isozymes, based on physiological liver development and serum protein levels. Yakugaku Zasshi 2010;130:613-20. PubMed
  12. Chien CF, Wu YT, Lee WC, et al. Herb-drug interaction of Andrographis paniculata extract and andrographolide on the pharmacokinetics of theophylline in rats. Chem Biol Interact 2010;184:458-65. PubMed
  13. Mills BM, Zaya MJ, Walters RR, et al. Current cytochrome P450 phenotyping methods applied to metabolic drug -drug interaction prediction in dogs. Drug Metab Dispos 2010;38:396-404. PubMed
  14. Turpault S, Brian W, Van Horn R, et al. Pharmacokinetic assessment of a five-probe cocktail for CYPs 1A2, 2C9, 2C19, 2D6, and 3A. Br J Clin Pharmacol 2009;68:928-35. PubMed
  15. Filimonova AA, Ziganshina LE, Ziganshin AU, Chichirov AA. On the possibility of patient phenotyping on the basis of cytochrome p-450 1A2 isoenzyme activity using caffeine as the test substrate. Eksp Klin Farmakol 2009;72:61-5.
  16. Jenkins J, Williams D, Deng Y, et al. Eltrombopag, an oral thrombopoietin receptor agonist, has no impact on the pharmacokinetic profile of probe drugs for cytochrome P450 isoenzymes CYP3A4, CYP1A2, CYP2C9 and CYP2C19 in healthy men: a cocktail analysis.
  17. Perera, V., Gross, A. S., and McLachlan, A. J. Caffeine and paraxanthine HPLC assay for CYP1A2 phenotype assessment using saliva and plasma. Biomed.Chromatogr. 2010;24(10):1136-1144. PubMed
  18. Izzo, A. A. and Ernst, E. Interactions between herbal medicines and prescribed drugs: an updated systematic review. Drugs 2009;69(13):1777-1798. PubMed
Moderate

ESTROGENS

2 of 3

Ethinyl Estradiol, Norethindrone also falls under ESTROGENS.

Theoretically, estrogens might increase the levels and adverse effects of caffeine.
Pu-erh tea contains caffeine. Estrogen inhibits caffeine metabolism.
Severity Moderate Likelihood Probable Evidence B

Interaction 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..

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

Here's the interesting twist with this combo: it's not your birth control pill that gets affected, it's the caffeine in your pu-erh tea. The estrogen part of your pill (ethinyl estradiol) can slow down how fast your body clears caffeine. That means the caffeine can hang around longer and feel stronger than usual.

In real life, that might show up as feeling jittery, a racing heart, trouble sleeping, or an upset stomach, especially if you drink several cups a day. Your contraceptive itself still works the same way, so this isn't about losing protection. If you notice you're more wired than normal, simply cutting back on caffeinated tea usually does the trick. Chat with your pharmacist if you have questions.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Pollock BG, Wylie M, Stack JA, et al. Inhibition of caffeine metabolism by estrogen replacement therapy in postmenopausal women. J Clin Pharmacol 1999;39:936-40. PubMed
Minor

CONTRACEPTIVE DRUGS

3 of 3

Ethinyl Estradiol, Norethindrone also falls under CONTRACEPTIVE DRUGS.

Theoretically, concomitant use might increase the effects and adverse effects of caffeine found in pu-erh tea.
Pu-erh tea contains caffeine. Oral contraceptive drugs can decrease caffeine clearance by 40% to 65%.
Severity Minor Likelihood Possible Evidence B

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 a small thing worth knowing if you drink pu-erh tea while taking your birth control pill (Loestrin, Ovcon, and similar combos of ethinyl estradiol and norethindrone). The pill doesn't change much about the tea itself, but it does slow down how fast your body clears caffeine, sometimes by 40 to 65 percent. That means the caffeine from your tea hangs around longer than it normally would.

In plain terms, you might feel the caffeine a bit more strongly: things like jitteriness, a faster heartbeat, trouble sleeping, or feeling wired. This is considered minor and is mostly theoretical, so there's no need to give up your tea. If caffeine tends to bother you, just go a little easier on it and chat with your pharmacist if you have questions.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Pollock BG, Wylie M, Stack JA, et al. Inhibition of caffeine metabolism by estrogen replacement therapy in postmenopausal women. J Clin Pharmacol 1999;39:936-40. PubMed
  2. Abernethy DR, Todd EL. Impairment of caffeine clearance by chronic use of low-dose oestrogen-containing oral contraceptives. Eur J Clin Pharmacol 1985;28:425-8. 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

Pu-erh Tea Also Interacts With Other Medications

Pu-erh Tea has 9 major, 447 moderate, 210 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.

Major 9 Moderate 447 Minor 210 No known interaction 2,164 (incl. Ethinyl Estradiol, Norethindrone)
Taking anything else?

Check Another of Your Medications Against Pu-erh Tea

Covers the 2,830 medications we’ve checked against Pu-erh Tea. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Ethinyl Estradiol, Norethindrone

This page covers Pu-erh Tea 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

How much people look this up

Where Pu-erh Tea 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 Pu-erh Tea
Steady interest

#1,340 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Ethinyl Estradiol, Norethindrone
Top 10%

#237 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 Pu-erh Tea

What is Pu-erh Tea?

  • Weight management
  • Cholesterol and heart health
  • Digestion after meals
  • Mental alertness
  • General antioxidant support

Pu-erh tea is a fermented, aged form of tea made from the same plant as green and black tea. It is enjoyed worldwide as a beverage and is sometimes promoted for weight loss, cholesterol, and digestion, but human evidence for these uses is limited. As a normal drink it is generally well tolerated, though it does contain caffeine.

Read the full Pu-erh Tea monograph & all interactions
Keep checking

Other Drugs & Pu-erh Tea

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

9Major
447Moderate
210Minor
2,163No known interaction
9 Major 447 Moderate 210 Minor 2,163 No interaction
Major

9 interactions

Moderate

447 interactions

Showing 60 of 447 moderate interactions — see all 447 on the Pu-erh Tea page.

Minor

210 interactions

Showing 60 of 210 minor interactions — see all 210 on the Pu-erh Tea page.

No interaction 2,163 drugs checked — show the list

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

Showing the 60 most looked-up of 2,163 medications checked with no known interaction — see the full Pu-erh Tea list.

See the full Pu-erh Tea 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
Pu-erh Tea 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 Pu-erh Tea and Ethinyl Estradiol, Norethindrone Together: Common Questions

Can you take Pu-erh Tea 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 Pu-erh Tea and Ethinyl Estradiol, Norethindrone?
Ethinyl Estradiol, Norethindrone belongs to more than one drug category, and Pu-erh Tea 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 Pu-erh Tea 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.