Drug & supplement interaction

Indian Long Pepper + Levothyroxine

Levothyroxine brand names: Euthyrox, Levothroid, Unithroid, Synthroid, Levoxyl, and others.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Indian Long Pepper and Levothyroxine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Levothyroxine states a food rule worth keeping to.

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Interaction report

Indian Long Pepper and Levothyroxine

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Levothyroxine and Indian Long Pepper in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Indian Long Pepper safety at a glance

Indian Long Pepper overall Use caution Likely fine as a food spice, but concentrated supplements lack strong safety data and piperine can affect how other substances are absorbed.
Pregnancy Avoid Medicinal amounts are not well studied and traditionally discouraged, so avoid supplement doses during pregnancy.
Breastfeeding Avoid There is not enough safety information, so avoid medicinal amounts while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Levothyroxine and Indian Long Pepper? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Levothyroxine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Levothyroxine is filed under 3 classifications — including thyroid hormone, oral drugs. Indian Long Pepper has documented interactions with 14 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), antidiabetes drugs (moderate) and cyclosporine (neoral, sandimmune) (moderate) — and none of Levothyroxine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Indian Long Pepper Does Interact With Other Medications

Indian Long Pepper has 893 moderate, 3 minor known drug interactions in our database — Levothyroxine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 893 Minor 3 No known interaction 1,934 (incl. Levothyroxine)
Taking anything else?

Check Another of Your Medications Against Indian Long Pepper

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

What to actually watch for

What Levothyroxine’s Own FDA Label Lists

This is not an interaction — none of it involves Indian Long Pepper. These are the most notable effects listed in the ADVERSE REACTIONS section of Levothyroxine’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • A change in thyroid levels Worth acting on
  • Bone thinning Worth acting on
  • Muscle weakness Worth acting on
  • A heart attack Worth acting on
  • Heart failure Worth acting on
  • Wheezing Worth acting on
  • Seizures Worth acting on
  • Chest pain Worth acting on
  • Shortness of breath Worth acting on
  • A severe allergic reaction Worth acting on

Showing the 10 most notable of 32 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Levothyroxine. Read the label on DailyMed › Indian Long Pepper’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Indian Long Pepper side to compare — that is a limit of the record, not a statement that Indian Long Pepper has no side effects.

How to take them

Some Levothyroxine Products Have a Food Rule — Indian Long Pepper Should Not Break It

At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach. Most supplements — Indian Long Pepper included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Levothyroxine on its own and move Indian Long Pepper to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Levothyroxine products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Levothyroxine Is Prescribed For, and What Indian Long Pepper Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Levothyroxine is a prescription medicine with approved uses on its FDA label. Indian Long Pepper is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Levothyroxine is prescribed for: Levothyroxine replaces or supplements the thyroid hormone your body isn't making enough of. It's used for hypothyroidism — an underactive thyroid — in adults, children, and even newborns, whether the cause is the thyroid gland itself, the pituitary gland, or the hypothalamus in the brain. It's also used alongside surgery and radioiodine treatment in people with certain types of thyroid cancer, to help suppress the hormone that can stimulate cancer growth. It is not meant for weight loss, treating benign thyroid nodules in people who have enough iodine, or for hypothyroidism during recovery from a temporary condition called subacute thyroiditis.

Indian Long Pepper has been studied for:

  • Depression studied, not established Indian Long Pepper has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Indian Long Pepper for depression

    Although there has been interest in using oral Indian long pepper for depression, there is insufficient reliable information about the clinical effects of Indian long pepper for this purpose.

  • Hypothyroidism studied, not established Indian Long Pepper has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Indian Long Pepper for hypothyroidism

    It is unclear if oral Indian long pepper is beneficial in patients with hypothyroidism.

  • Cancer studied, not established Indian Long Pepper has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Indian Long Pepper for cancer

    Although there has been interest in using oral Indian long pepper for cancer, there is insufficient reliable information about the clinical effects of Indian long pepper for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Levothyroxine on your own; if you are taking Indian Long Pepper for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Indian Long Pepper or Levothyroxine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Indian Long Pepper or Levothyroxine, 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 Levothyroxine

This page covers Indian Long Pepper only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levothyroxine page lists 50 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Tiratricol (major), Acetyl-l-carnitine (moderate), Alpha-lipoic Acid (moderate) and Ascophyllum Nodosum (moderate).

By severity: 2 major · 39 moderate · 9 minor.

From our pharmacist’s overview on the Levothyroxine page

“Levothyroxine replaces a hormone your body measures in tiny amounts, so small shifts in its blood level show up in how you feel, and I treat this list with genuine care. Nearly everything on it does one of two things: blocks the pill from being absorbed in the gut, the way everyday minerals like calcium do by binding it into complexes,…”

Reviewed by 2 · Jul 18, 2026

Open the Levothyroxine interaction page

One more smart check

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

We hold 597 real supplement products containing Indian Long Pepper, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Indian Long Pepper. Even though Indian Long Pepper itself has no known interaction with Levothyroxine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Indian Long Pepper and Levothyroxine 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 Indian Long Pepper
Top 25%

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

29 days ago today
Medication Levothyroxine
Top 10

#2 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Indian Long Pepper reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Indian Long Pepper and Levothyroxine records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Indian Long Pepper

What is Indian Long Pepper?

Indian Long Pepper
  • Digestive upset
  • Respiratory and cough complaints
  • Boosting absorption of other supplements
  • Pain and inflammation
  • General wellness in Ayurveda

Indian long pepper (pippali) is a spice long used in Ayurvedic medicine and is best known for its piperine content, which may increase how well the body absorbs certain other substances. Modern human research on its health benefits is limited, so use it cautiously and let your pharmacist or doctor know if you take it regularly.

Piper longum · Piperaceae · Dried fruit (and sometimes the root) · Dried fruit (spice), powder, capsules, extracts, and traditional Ayurvedic formulas

An interaction check asks whether these two react with each other — it does not ask whether Indian Long Pepper is a good idea for someone in your situation. Here is what our Indian Long Pepper record says about it on its own.

Indian Long Pepper: dosing

There is no well-established standard dose of Indian long pepper for any health condition. Traditional Ayurvedic use and modern supplement products vary widely.The safest approach is to follow the directions on the product label and not exceed them.

From our Indian Long Pepper monograph — the full record covers uses, side effects and every documented interaction.

Read the full Indian Long Pepper monograph & all interactions
Medication

About Levothyroxine

What Is Levothyroxine Used For?

Brand names: Euthyrox, Levothroid, Unithroid, Synthroid, Levoxyl, Levo-T, Eltroxin, Estre, Levothyroxine, Novothyrox, Levolet

Levothyroxine replaces or supplements the thyroid hormone your body isn't making enough of. It's used for hypothyroidism — an underactive thyroid — in adults, children, and even newborns, whether the cause is the thyroid gland itself, the pituitary gland, or the hypothalamus in the brain.

It's also used alongside surgery and radioiodine treatment in people with certain types of thyroid cancer, to help suppress the hormone that can stimulate cancer growth. It is not meant for weight loss, treating benign thyroid nodules in people who have enough iodine, or for hypothyroidism during recovery from a temporary condition called subacute thyroiditis.

See full Levothyroxine drug information
Keep checking

Other Drugs & Indian Long Pepper

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

0Major
893Moderate
3Minor
1,933No known interaction
893 Moderate 3 Minor 1,933 No interaction
Moderate

893 interactions

Showing 60 of 893 moderate interactions — see all 893 on the Indian Long Pepper page.

Minor

3 interactions

No interaction 1,933 drugs checked — show the list

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

Showing the 60 most looked-up of 1,933 medications checked with no known interaction — see the full Indian Long Pepper list.

See the full Indian Long Pepper interactions page
See every supplement checked against Levothyroxine, ranked by severity
Evidence & sources

Indian Long Pepper References

The 12 references that drive our Indian Long Pepper monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Bano G, Amla V, Raina RK, et al. The effect of piperine on pharmacokinetics of phenytoin in healthy volunteers. Planta Med 1987;53:568-9. PubMed
  2. Bano G, et al. Effect of piperine on bioavailability and pharmacokinetics of propranolol and theophylline in healthy volunteers. Eur J Clin Pharmacol 1991;41;615-7. PubMed
  3. Bhardwaj RK, Glaeser H, Becquemont L, et al. Piperine, a major constituent of black pepper, inhibits human P-glycoprotein and CYP3A4. J Pharmacol Exp Ther 2002;302:645-50. PubMed
  4. Pattanaik S, Hota D, Prabhakar S, et al. Pharmacokinetic interaction of a single dose of piperine with steady-state carbamazepine in epilepsy patients. Phytother Res 2009;23:1281-6.
  5. Kasibhatta, R. and Naidu, M. U. Influence of piperine on the pharmacokinetics of nevirapine under fasting conditions: a randomised, crossover, placebo-controlled study. Drugs R.D. 2007;8(6):383-391. PubMed
  6. Mujumdar, A. M., Dhuley, J. N., Deshmukh, V. K., Raman, P. H., Thorat, S. L., and Naik, S. R. Effect of piperine on pentobarbitone induced hypnosis in rats. Indian J Exp.Biol. 1990;28(5):486-487.
  7. Panda, S. and Kar, A. Piperine lowers the serum concentrations of thyroid hormones, glucose and hepatic 5'D activity in adult male mice. Horm.Metab Res. 2003;35(9):523-526. PubMed
  8. Hiwale, A. R., Dhuley, J. N., and Naik, S. R. Effect of co-administration of piperine on pharmacokinetics of beta-lactam antibiotics in rats. Indian J Exp.Biol. 2002;40(3):277-281.
  9. Han, Y., Chin Tan, T. M., and Lim, L. Y. In vitro and in vivo evaluation of the effects of piperine on P-gp function and expression. Toxicol.Appl.Pharmacol. 8-1-2008;230(3):283-289. PubMed
  10. Sharma, P., Varma, M. V., Chawla, H. P., and Panchagnula, R. In situ and in vivo efficacy of peroral absorption enhancers in rats and correlation to in vitro mechanistic studies. Farmaco 2005;60(11-12):874-883. PubMed
  11. Zutshi, R. K., Singh, R., Zutshi, U., Johri, R. K., and Atal, C. K. Influence of piperine on rifampicin blood levels in patients of pulmonary tuberculosis. J Assoc.Physicians India 1985;33(3):223-224.
  12. Yadav V, Krishnan A, Vohora D. A systematic review on Piper longum L.: Bridging traditional knowledge and pharmacological evidence for future translational research. J Ethnopharmacol. 2020;247:112255. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Indian Long Pepper and Levothyroxine Together: Common Questions

Is it safe to take Indian Long Pepper with Levothyroxine?
We do not list a known interaction between Indian Long Pepper and Levothyroxine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Should I take Indian Long Pepper and Levothyroxine at the same time of day?
At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Levothyroxine on its own and move Indian Long Pepper to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
Are Indian Long Pepper and Levothyroxine used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Indian Long Pepper in each. That is a conversation for your prescriber, especially if Levothyroxine is being adjusted to a target.
How was the Indian Long Pepper and Levothyroxine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine is filed under 3 classifications, and Indian Long Pepper has documented interactions with 14 drug classes — none of Levothyroxine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Indian Long Pepper interact with any other medications?
Yes. Indian Long Pepper has 896 documented drug interactions in our database — Levothyroxine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Levothyroxine interact with any supplements?
Yes. Levothyroxine has documented interactions with 50 supplements in our database — Indian Long Pepper is not one of them. The Levothyroxine interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Indian Long Pepper monograph Uses, safety profile, and every drug interaction in one place Levothyroxine drug information The full plain-English guide to this medication Levothyroxine supplement interactions Every supplement checked against Levothyroxine, 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 References The 12 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levothyroxine and Indian Long Pepper?

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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.