Drug & supplement interaction

White Pepper + Levonorgestrel

Levonorgestrel brand names: Plan B, Mirena, Levonelle One Step, Levonelle 1500, Norgeston, and others.

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

White Pepper has a moderate interaction with Levonorgestrel. In vitro evidence suggests that piperine, a constituent of white pepper, inhibits cytochrome P450 3A4 (CYP3A4).

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

White Pepper and Levonorgestrel

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Levonorgestrel

Levonorgestrel falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group White Pepper interacts with.

In vitro evidence suggests that piperine, a constituent of white pepper, inhibits cytochrome P450 3A4 (CYP3A4). Theoretically, concomitant use with white pepper might increase the effects and side effects of drugs metabolized by CYP3A4.
Some drugs metabolized by CYP3A4 include some calcium channel blockers (diltiazem, nicardipine, verapamil), chemotherapeutic agents (etoposide, paclitaxel, vinblastine, vincristine, vindesine), antifungals (ketoconazole, itraconazole), glucocorticoids, cisapride (Propulsid), alfentanil (Alfenta), fentanyl (Sublimaze), losartan (Cozaar), fluoxetine (Prozac), midazolam (Versed), omeprazole (Prilosec), ondansetron (Zofran), propranolol (Inderal), fexofenadine (Allegra), and numerous others.
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 levonorgestrel (the hormone in Plan B and IUDs like Mirena). Your liver uses an enzyme called CYP3A4 to help clear this hormone out of your body. Lab studies suggest piperine, the spicy compound in white pepper, can mildly slow that enzyme down. In theory, that could let a bit more levonorgestrel hang around, which might mean a slightly stronger effect or more of the usual nuisances like spotting, nausea, breast tenderness, or headache.

The important part: this is theoretical, based only on test-tube research, not real people. The white pepper you sprinkle on dinner is very unlikely to matter. If you're using a concentrated piperine supplement, just mention it to your pharmacist or doctor so they can weigh in.

Contact Dr. Brian directly if you have additional questions on this interaction

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

White Pepper Also Interacts With Other Medications

White Pepper has 976 moderate, 3 minor known drug interactions in our database — the Levonorgestrel one above is one of them. If you take anything else, check it against the full list below.

Moderate 976 Minor 3 No known interaction 1,851 (incl. Levonorgestrel)
Taking anything else?

Check Another of Your Medications Against White Pepper

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

From our Q&A

Questions About White Pepper or Levonorgestrel

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers White Pepper or Levonorgestrel, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Levonorgestrel

This page covers White Pepper only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levonorgestrel page lists 191 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 · 142 moderate · 43 minor.

From our pharmacist’s overview on the Levonorgestrel page

“St. John's wort tops my worry list for anyone using levonorgestrel (Plan B, Mirena, and other birth control).”

Reviewed by 2 · Jul 18, 2026

Open the Levonorgestrel interaction page

One more smart check

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

We hold 2 real supplement products containing White Pepper, each one broken down to its full ingredient list — and combination products often carry several ingredients besides White Pepper. Your product may carry other ingredients that interact with Levonorgestrel too, on top of White Pepper — 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 White Pepper and Levonorgestrel 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 White Pepper
Top half

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

29 days ago today
Medication Levonorgestrel
Top 25%

#437 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 White Pepper

What is White Pepper?

  • Digestive upset
  • Seasoning and appetite support
  • Cough and cold remedies (traditional)
  • Minor aches and pains (traditional)
  • Antimicrobial (traditional)

White pepper comes from the same plant as black pepper and is mostly used as a kitchen spice. In normal food amounts it is generally safe for most people, but there is little solid human research supporting its use as a medicine. Talk with your pharmacist or doctor before using concentrated supplements, especially if you are pregnant, breastfeeding, or have a health condition.

Read the full White Pepper monograph & all interactions
Medication

About Levonorgestrel

What Is Levonorgestrel Used For?

Brand names: Plan B, Mirena, Levonelle One Step, Levonelle 1500, Norgeston, Skyla, Liletta, Kyleena

Levonorgestrel is used in two very different ways, depending on the product.

The intrauterine systems (Mirena, Liletta, Kyleena and Skyla) prevent pregnancy for a set number of years. Mirena and Liletta are also used to treat heavy menstrual bleeding in women who choose intrauterine contraception. The oral tablets are used for emergency contraception, to reduce the chance of pregnancy after unprotected sex.

See full Levonorgestrel drug information
Keep checking

Other Drugs & White Pepper

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

0Major
976Moderate
3Minor
1,850No known interaction
976 Moderate 3 Minor 1,850 No interaction
Moderate

976 interactions

Showing 60 of 976 moderate interactions — see all 976 on the White Pepper page.

Minor

3 interactions

No interaction 1,850 drugs checked — show the list

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

Showing the 60 most looked-up of 1,850 medications checked with no known interaction — see the full White Pepper list.

See the full White Pepper interactions page
See every supplement checked against Levonorgestrel, 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
White Pepper monograph › Uses, safety, and every drug interaction in one place Levonorgestrel supplement interactions › Every supplement checked against Levonorgestrel, ranked by severity Levonorgestrel drug information › The full plain-English guide to this medication 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 White Pepper and Levonorgestrel Together: Common Questions

Can you take White Pepper with Levonorgestrel?
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.
How serious is the White Pepper and Levonorgestrel 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

Still Have a Question About Levonorgestrel and White Pepper?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.