The short answer
Concentrated piperine raised theophylline exposure in a small human study. Ask the prescriber before adding a piperine supplement.
What this answer covers
Isolated piperine, including standardized enhancer supplements; ordinary culinary black pepper is not the studied exposure.
- Supplement or preparation
- Piperine
- Medication ingredient
- theophylline
What the study found
Six volunteers received oral theophylline with or without piperine taken daily for a week. Piperine increased peak concentration, total exposure and elimination half-life. The experiment was too small to determine clinical toxicity risk.
Concentrated piperine is the relevant exposure
The study used 20 mg of isolated piperine daily. It does not establish the effect of pepper used as seasoning, nor does it make that study amount an appropriate dose for you.
Use a monitored plan
Keep theophylline dosing and formulation consistent with your prescription. Tell the prescriber about supplement starts, stops and dose changes. Separating products by a few hours has not been shown to prevent changes in drug clearance, and a study dose is not a recommended supplement dose.
Recognize possible toxicity
Contact the prescriber promptly for repeated nausea or vomiting, new insomnia or tremor after a product change. A seizure, fainting or a sustained rapid or irregular heartbeat needs urgent assessment. A blood theophylline measurement may be needed; symptoms alone cannot determine the level.
Evidence and practical considerations
Absorption & effectiveness
Direct human evidence supports increased systemic theophylline exposure with repeated isolated piperine. A gut-absorption-only mechanism and equivalence to black pepper foods are not established.
- Exact scope
- Isolated piperine, including standardized enhancer supplements; ordinary culinary black pepper is not the studied exposure. with Exact theophylline anhydrous extended-release tablets and oral solution. Exact RxNorm IN10438. Oral anhydrous theophylline formulations distinguished; intravenous and aminophylline study exposures are identified separately.
- Medication form and route
- oral
- Timing or duration
- Source-specific single-dose, repeated-dose and observational exposures distinguished.
What remains uncertain
- Six subjects, single oral theophylline dose and seven-day piperine regimen; no clinical toxicity rate or proven safe interval.
Factors that may matter: preparation and plant part; clinical indication; dose; other medicines; baseline alertness.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed theophylline.
Variable clearance, narrow therapeutic range and serum concentration monitoring; toxicity can include arrhythmias and seizures; label specifically warns about St John’s wort and ephedrine.
How this applies: Exact RxNorm IN10438. Oral anhydrous theophylline formulations distinguished; intravenous and aminophylline study exposures are identified separately.
No universal supplement dose, interval, event rate or untested formulation equivalence.
Source 2: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed theophylline.
Variable clearance, narrow therapeutic range and serum concentration monitoring; toxicity can include arrhythmias and seizures; label specifically warns about St John’s wort and ephedrine.
How this applies: Exact RxNorm IN10438. Oral anhydrous theophylline formulations distinguished; intravenous and aminophylline study exposures are identified separately.
No universal supplement dose, interval, event rate or untested formulation equivalence.
Source 3: original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Six volunteers in the theophylline crossover group.
Higher theophylline peak concentration, AUC and elimination half-life with piperine.
How this applies: Only the named drug, preparation, route and measured endpoints apply.
Small single-dose study, no measured clinical toxicity rate or validated spacing. Isolated piperine is not culinary pepper; higher exposure does not by itself prove increased gut absorption.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Research summary published | |
| Article prepared | |
| Current exact available claims adjudicated using original captures and explicit identity and comparator limits. |
Article revision: 414924a35e3ac5a6
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.