The short answer
Possibly. In a small study from Jammu, six healthy volunteers took a single dose of theophylline on its own, and again after a week of daily piperine, the compound that gives pippali (long pepper) and black pepper their bite. With piperine, theophylline reached a higher peak, stayed in the body longer and total exposure rose.
The study used purified piperine, not pippali churna or capsules, and the piperine in pippali products varies. Theophylline has a narrow therapeutic index, and too much can cause persistent vomiting, an irregular heartbeat or seizures. If you take theophylline, tell your prescribing doctor before you start anything with pippali, black pepper extract or piperine, and ask whether your theophylline level should be checked.
At a glance
| What was seen | How it may work | Direction | Evidence |
|---|---|---|---|
| Higher peak level, higher total exposure and longer half-life of theophylline[1] | Not established | More theophylline in the blood, for longer | Small clinical study |
No listing is not a clearance. A missing interaction here never means a combination is safe.
The evidence, study by study
Trial in healthy volunteers, Jammu, 1991 Small clinical study
Six healthy volunteers took a single 150 mg dose of theophylline alone, and again after taking 20 mg of piperine daily for seven days. With piperine, theophylline's peak level and total exposure (AUC) were higher, and it took longer to leave the body. The abstract does not say how large the changes were. Nobody in the study had asthma or was on long-term theophylline.[1]
What your doctor may watch for
- Your theophylline blood level. The US drug regulator classes theophylline as a narrow therapeutic index drug.[3]
- Persistent vomiting, a racing or irregular heartbeat, or a seizure. The theophylline label lists these among the effects of too much theophylline.[2]
What to tell your prescribing doctor
You can read this out, or show them this page:
“I am taking, or planning to take, a product that contains pippali, black pepper or piperine (name of product, dose) along with theophylline. A small study found piperine raised theophylline levels. Should my theophylline level be checked?”
Withheld until review
Questions people ask
I take a cough churna that contains pippali. Does this apply?
Pippali contains piperine, but this study did not measure how much piperine a churna gives, or test a churna with theophylline. Show the product label to your prescribing doctor.[1]
Does black pepper in food count?
We found no study of pepper in food with theophylline. The volunteers here took purified piperine every day for a week, which is a different exposure from pepper in a meal.[1]
Will taking them a few hours apart prevent it?
The study did not test timing, so there is no evidence that spacing them apart helps. Ask your prescribing doctor.[1]
Related
Pippali, black pepper and propranolol
In one small study, a week of piperine, the compound in pippali and black pepper, raised propranolol levels in healthy volunteers.
FormulationSitopaladi Churna
A classical cough powder, about half sugar by weight. It contains pippali; piperine, a pepper compound, raised phenytoin levels in a small study.
FormulationTalisadi Churna
A classical cough and digestion powder, two-thirds sugar by weight, with pippali and black pepper. We have not found a study of it in people.
Sources
- Bano G, Raina RK, Zutshi U, Bedi KL, Johri RK, Sharma SC. Effect of piperine on bioavailability and pharmacokinetics of propranolol and theophylline in healthy volunteers. Eur J Clin Pharmacol. 1991;41(6):615-617. PMID 1815977.
- Theophylline extended-release tablets, US prescribing information, Clinical Pharmacology and Adverse Reactions (DailyMed).
- US Food and Drug Administration. Draft guidance on theophylline extended-release capsules, August 2020.
Awaiting review by The Good Vaidya Medical Board. Prepared from the sources below and checked against each one.
Published 4 November 2026 · Last updated 4 November 2026
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