Drug & supplement interaction

Guarana + Levonorgestrel, Ethinyl Estradiol

Levonorgestrel, Ethinyl Estradiol brand names: Nordette, Logynon ED, Microgynon 30, Ovranette, Trinordiol, and others.

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

Levonorgestrel, Ethinyl Estradiol falls into 3 drug categories that Guarana can interact with; the most serious is rated moderate. Theoretically, estrogens might increase the levels and adverse effects of caffeine.

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

Guarana and Levonorgestrel, Ethinyl Estradiol

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

Why Are There 3 Interactions?

Guarana interacts with whole categories of medication. Levonorgestrel, Ethinyl Estradiol falls into 3 of those categories, so it can interact with Guarana 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 Levonorgestrel, Ethinyl Estradiol

Levonorgestrel, Ethinyl Estradiol falls under ESTROGENS — the group Guarana interacts with.

Theoretically, estrogens might increase the levels and adverse effects of caffeine.
Guarana 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 a twist that surprises a lot of people: with this combo, it's your birth control pill that affects the guarana, not the other way around. The estrogen (ethinyl estradiol) in pills like Microgynon or Ovranette slows down how your liver clears caffeine. Since guarana is basically concentrated caffeine, it can hang around in your body longer and hit harder than you'd expect.

In real life, that can mean more jitteriness, a racing or pounding heart, trouble sleeping, headaches, or feeling anxious, especially if you also drink coffee or energy drinks. This won't change how well your pill prevents pregnancy. If you notice these effects, just ease back on caffeine and chat with your pharmacist or doctor about a comfortable amount.

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

CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS

2 of 3

Levonorgestrel, Ethinyl Estradiol also falls under CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS.

Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Guarana contains caffeine. Caffeine is metabolized by the CYP1A2 enzyme. Theoretically, drugs that inhibit CYP1A2 may decrease the rate of caffeine clearance and increase caffeine levels.
Severity Minor 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 is the thing to keep straight: this interaction works the other way around from what you might expect. Your birth control pill (the estrogen part especially) can mildly slow down the CYP1A2 enzyme that clears caffeine from your body. Guarana is basically concentrated caffeine, so pairing the two means caffeine may stick around a little longer than usual.

In real life that could feel like more jitteriness, a racing or pounding heart, trouble sleeping, or feeling wired and anxious. Your pill itself keeps working fine, this is about caffeine building up. The evidence here is weak (mostly lab-based) and the effect is considered minor, so a normal cup of coffee probably won't bother you. If guarana ramps up your caffeine side effects, just ease back on it and check with your pharmacist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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
  2. Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin Pharmacokinet 2000;39:127-53. PubMed
Minor

CONTRACEPTIVE DRUGS

3 of 3

Levonorgestrel, Ethinyl Estradiol also falls under CONTRACEPTIVE DRUGS.

Theoretically, concomitant use might increase the effects and adverse effects of caffeine found in guarana.
Guarana contains caffeine. Oral contraceptives decrease the rate of 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 the thing to know if you take a birth control pill like Nordette or Microgynon along with guarana: this isn't really about the pill becoming weaker or stronger. Your birth control still works the same. Instead, it's the caffeine in guarana that gets affected. The estrogen in your pill slows down how fast your body clears caffeine, by roughly half, so caffeine lingers longer than it normally would.

In plain terms, the guarana may hit you harder and stick around. You might notice more jitteriness, a racing heart, trouble sleeping, or feeling anxious. It's a minor, theoretical concern, not dangerous for most people, but if you're caffeine-sensitive you may simply want less guarana. Check with your pharmacist if you're unsure.

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

Guarana Also Interacts With Other Medications

Guarana has 8 major, 461 moderate, 185 minor known drug interactions in our database — the Levonorgestrel, Ethinyl Estradiol one above is among them. If you take anything else, check it against the full list below.

Major 8 Moderate 461 Minor 185 No known interaction 2,176 (incl. Levonorgestrel, Ethinyl Estradiol)
Taking anything else?

Check Another of Your Medications Against Guarana

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

Everything else you take

See Every Supplement That Interacts With Levonorgestrel, Ethinyl Estradiol

This page covers Guarana only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levonorgestrel, Ethinyl Estradiol page lists 241 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 · 197 moderate · 38 minor.

Open the Levonorgestrel, Ethinyl Estradiol interaction page

One more smart check

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

We hold 1,430 real supplement products containing Guarana, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Guarana. Your product may carry other ingredients that interact with Levonorgestrel, Ethinyl Estradiol too, on top of Guarana — 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 Guarana and Levonorgestrel, 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 Guarana
Top 10%

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

29 days ago today
Medication Levonorgestrel, Ethinyl Estradiol
Top half

#778 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 Guarana

What is Guarana?

Guarana
  • Energy and alertness
  • Reducing fatigue
  • Weight loss support
  • Athletic performance
  • Mental focus

Guarana is an Amazonian seed that is naturally high in caffeine, which explains most of its stimulant and energy effects. While it may give a short-term boost in alertness and reduce fatigue, strong evidence for weight loss or major performance gains is limited, and it carries the same risks as too much caffeine. Talk to your pharmacist or doctor before using it, especially if you have heart problems, anxiety, or are pregnant.

Read the full Guarana monograph & all interactions
Keep checking

Other Drugs & Guarana

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

8Major
461Moderate
185Minor
2,175No known interaction
8 Major 461 Moderate 185 Minor 2,175 No interaction
Major

8 interactions

Moderate

461 interactions

Showing 60 of 461 moderate interactions — see all 461 on the Guarana page.

Minor

185 interactions

Showing 60 of 185 minor interactions — see all 185 on the Guarana page.

No interaction 2,175 drugs checked — show the list

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

Showing the 60 most looked-up of 2,175 medications checked with no known interaction — see the full Guarana list.

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

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