Drug & supplement interaction

Tiratricol + Nivolumab

Nivolumab brand name: Opdivo.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Tiratricol and Nivolumab 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 Nivolumab states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Tiratricol and Nivolumab

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 Nivolumab and Tiratricol 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.

Tiratricol safety at a glance

Tiratricol overall Avoid It is a potent thyroid-active drug that the FDA has warned against using in supplements.
Pregnancy Possibly Safe When used orally under medical supervision for treating fetal hypothyroidism. Read the full pregnancy detail
Breastfeeding Avoid It is unsafe and may pass thyroid effects to the infant, so avoid completely.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Nivolumab and Tiratricol? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Nivolumab

Interactions in our licensed database are recorded against drug classes, not just single drug names. Nivolumab is filed under a single classification — antineoplastics. Tiratricol has documented interactions with 4 drug classes — the most serious being thyroid hormone (major), anticoagulant/antiplatelet drugs (moderate) and antidiabetes drugs (moderate) — and none of Nivolumab’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

Tiratricol Does Interact With Other Medications

Tiratricol has 16 major, 209 moderate known drug interactions in our database — Nivolumab isn’t one of them. If you take anything else, check it against the full list below.

Major 16 Moderate 209 No known interaction 2,605 (incl. Nivolumab)
Taking anything else?

Check Another of Your Medications Against Tiratricol

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

What to actually watch for

No Interaction Found — But Data Suggests Tiratricol and Nivolumab May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 4 of them are worth acting on rather than waiting out — marked below.

  • A change in thyroid levels Worth acting on Additional detail

    Tiratricol

    “Orally, tiratricol is associated with symptoms of both thyrotoxicosis and hypothyroidism. Two young adults presented with symptoms of hypothyroidism, including lethargy, muscle weakness, and weight gain despite loss of appetite, after taking tiratricol 3000-4000 mcg daily for 5 weeks or 6000 mcg daily for 3 weeks.”

    Tiratricol · Natural Medicines adverse-effect record, reported in fatigue.

    3 sources cited
    1. 98213. Scally MC, Hodge A. A report of hypothyroidism induced by an over-the-counter fat loss supplement (Tiratricol). Int J Sport Nutr Exerc Metab 2003;13(1):112-6. PubMed
    2. 98214. Bauer BA, Elkin PL, Erickson D, Klee GG, Brennan MD. Symptomatic hyperthyroidism in a patient taking the dietary supplement tiratricol. Mayo Clin Proc 2002;77(6):587-90. PubMed
    3. 1620. Chow WS, Lam KS. An overweight woman with galactorrhoea. Postgrad Med J 1998;74:121-2. PubMed

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab. Read the label on DailyMed ›

  • A heart attack Worth acting on Additional detail

    Tiratricol

    “Orally, tiratricol is well tolerated.

    Most Common Adverse Effects:

    Orally: Diarrhea, fatigue, insomnia, lethargy, nervousness, tachycardia, tremors, and weight changes.

    Serious Adverse Effects (Rare):

    Orally: Cardiac arrhythmia, heart attack paralysis, stroke.”

    Tiratricol · Natural Medicines adverse-effect record, reported in arrhythmia.

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab. Read the label on DailyMed ›

  • An irregular heartbeat Worth acting on Additional detail

    Tiratricol

    “Orally, tiratricol has been associated with increased pulse and blood pressure, tachycardia, chest pain, cardiac arrhythmias, and heart attacks.”

    Tiratricol · Natural Medicines adverse-effect record, reported in arrhythmia.

    1 source cited
    1. 1605. US Food and Drug Administration (FDA). Dietary Supplements Containing Tiratricol: FDA Warns Consumers Against Consuming Tiratricol. Potent Thyroid Hormone Promoted as Dietary Supplement, Nov 21, 2000. Available at: https://www.fda.gov/inspections-complian

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab. Read the label on DailyMed ›

  • Chest pain Worth acting on Additional detail

    Tiratricol

    Recorded for Tiratricol in the same Natural Medicines adverse-effect record shown under An irregular heartbeat above.

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab. Read the label on DailyMed ›

  • Weight loss / Reduced appetite Additional detail

    Tiratricol

    Recorded for Tiratricol in the same Natural Medicines adverse-effect record shown under A change in thyroid levels above.

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab. Read the label on DailyMed ›

  • Trouble sleeping / Tiredness reported in 4.3% of FDA reports for Nivolumab Additional detail

    Tiratricol

    Recorded for Tiratricol in the same Natural Medicines adverse-effect record shown under A heart attack above.

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Stomach pain Additional detail

    Tiratricol

    “Orally, tiratricol has been associated with diarrhea and abdominal cramps.”

    Tiratricol · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 1605. US Food and Drug Administration (FDA). Dietary Supplements Containing Tiratricol: FDA Warns Consumers Against Consuming Tiratricol. Potent Thyroid Hormone Promoted as Dietary Supplement, Nov 21, 2000. Available at: https://www.fda.gov/inspections-complian

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab. Read the label on DailyMed ›

  • Diarrhea reported in 5.4% of FDA reports for Nivolumab Additional detail

    Tiratricol

    Recorded for Tiratricol in the same Natural Medicines adverse-effect record shown under A heart attack above.

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Tiratricol but not commonly for Nivolumab: muscle weakness, anxiety or restlessness, a fast or pounding heartbeat and weight gain.

Effects for Nivolumab come from the ADVERSE REACTIONS section of its FDA label; effects for Tiratricol come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 96,645 voluntary FDA FAERS reports for Nivolumab that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Tiratricol in Pregnancy & Breastfeeding

Pregnancy Possibly Safe

When used orally under medical supervision for treating fetal hypothyroidism.

Pregnancy Likely Unsafe

When used orally without medical supervision due to possible risk of fetal heart damage; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

Some Nivolumab Products Have a Food Rule — Tiratricol Should Not Break It

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

Table 2: Recommended Dosages of Intravenous OPDIVO in Combination with Other Therapeutic Agents Indication Recommended OPDIVO Dosage Duration of Therapy Unresectable or metastatic melanoma 1 mg/kg every 3 weeks with ipilimumab 3 mg/kg In combination with ipilimumab for a maximum of 4 doses or until unacceptable toxicity, whichever occurs earlier Adult patients and pediatric patients aged 12 years

From the Dosage and Administration section of the FDA label we read for Nivolumab — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

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.

Everything else you take

See Every Supplement That Interacts With Nivolumab

This page covers Tiratricol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nivolumab page lists 1 supplement it has a documented interaction with, worst first, each one explained.

The most serious there right now: American Pawpaw (minor).

By severity: 1 minor.

From our pharmacist’s overview on the Nivolumab page

“Nivolumab (Opdivo) is an immunotherapy infusion that trains the body's own immune system to recognize and attack cancer cells, the kind of drug you might expect to carry a long list of supplement warnings. It does not.”

Reviewed by 2 · Jul 18, 2026

Open the Nivolumab interaction page

How much people look this up

Where Tiratricol and Nivolumab 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 Tiratricol
Top half

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

29 days ago today
Medication Nivolumab
Steady interest

#2,164 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 Tiratricol reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Tiratricol and Nivolumab records this page draws on were last updated July 11, 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 Tiratricol

What is Tiratricol?

  • Weight loss
  • Fat burning
  • Boosting metabolism
  • Bodybuilding and cutting
  • Thyroid-related supplementation

Tiratricol (also called TRIAC) is a powerful synthetic thyroid hormone metabolite, not a natural herb, and it has been illegally added to some weight-loss and bodybuilding supplements. It can cause serious heart and thyroid problems, and the U.S. FDA has warned consumers not to use products containing it. It is not a safe or approved dietary supplement, and you should avoid it.

Synthetic thyroid hormone metabolite (not a plant) · Tablets, capsules, powders (often sold in weight-loss or 'fat-burner' products)

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

Tiratricol: dosing

There is no safe, established dietary supplement dose for tiratricol, and we will not suggest one. It is not an approved supplement, and the FDA has warned against using products that contain it.Do not try to dose this on your own.

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

Read the full Tiratricol monograph & all interactions
Medication

About Nivolumab Injection

What Is Nivolumab Injection Used For?

Brand name: Opdivo

Opdivo (nivolumab) is used to treat many types of cancer in adults, and some in patients 12 years and older. It can be used alone or in combination with other therapies depending on the cancer type and stage. Cancers it treats include melanoma (including after surgery to reduce the chance of the cancer coming back), non-small cell lung cancer, malignant pleural mesothelioma, advanced renal cell carcinoma (kidney cancer), classical Hodgkin lymphoma, squamous cell carcinoma of the head and neck, urothelial carcinoma (bladder cancer), colorectal cancer with specific genetic features (MSI-H or dMMR), hepatocellular carcinoma (liver cancer), esophageal cancer, gastroesophageal junction cancer, and gastric (stomach) cancer.

Some uses require the tumor to test positive for a protein called PD-L1, and some are specific to certain stages of disease or prior treatments received. Your oncologist will determine which use applies to your situation.

Most-Reported Side Effects for Nivolumab

From FAERS, the FDA’s public side-effect reporting system (96,645 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Malignant neoplasm progression 9,878 reports
Diarrhea 5,251 reports
Fatigue 4,195 reports
Fever 3,721 reports
Nausea 3,182 reports
See full Nivolumab Injection drug information
Keep checking

Other Drugs & Tiratricol

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

16Major
209Moderate
0Minor
2,604No known interaction
16 Major 209 Moderate 2,604 No interaction
Major

16 interactions

Moderate

209 interactions

Showing 60 of 209 moderate interactions — see all 209 on the Tiratricol page.

No interaction 2,604 drugs checked — show the list

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

Showing the 60 most looked-up of 2,604 medications checked with no known interaction — see the full Tiratricol list.

See the full Tiratricol interactions page
See every supplement checked against Nivolumab, ranked by severity
Evidence & sources

Tiratricol References

The 12 references that drive our Tiratricol 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. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. US Food and Drug Administration (FDA). Dietary Supplements Containing Tiratricol: FDA Warns Consumers Against Consuming Tiratricol. Potent Thyroid Hormone Promoted as Dietary Supplement, Nov 21, 2000. Available at: https://www.fda.gov/inspections-complian
  3. Nicolini U, Venegoni E, Acaia B, et al. Prenatal treatment of fetal hypothyroidism: is there more than one option? Prenat Diagn 1996;16:443-8. DOI
  4. Asteria C, Rajanayagam O, Collingwood TN, et al. Prenatal diagnosis of thyroid hormone resistance. J Clin Endocrinol Metab 1999;84:405-10. PubMed
  5. Mueller-Gaertner HW, Schneider C. 3,5,3'-Triiodothyroacetic acid minimizes the pituitary thyrotrophin secretion in patients on levo-thyroxine therapy after ablative therapy for differentiated thyroid carcinoma. Clin Endocrinol (Oxf) 1988;28:345-51.
  6. Chow WS, Lam KS. An overweight woman with galactorrhoea. Postgrad Med J 1998;74:121-2. PubMed
  7. Lledo Carreres M, Lajo Garrido JL, Gonzalez Rico M, et al. Toxic internuclear ophthalmoplegia related to antiobesity treatment. Ann Pharmacother 1992;26:1457-8. PubMed
  8. Hawkey CM, Olsen EG, Symons C. Production of cardiac muscle abnormalities in offspring of rats receiving triiodothyroacetic acid (triac) and the effect of beta adrenergic blockade. Cardiovasc Res 1981;15:196-205. PubMed
  9. Olsen EG, Symons C, Hawkey C. Effect of triac on the developing heart. Lancet 1977;2:221-3. PubMed
  10. Scally MC, Hodge A. A report of hypothyroidism induced by an over-the-counter fat loss supplement (Tiratricol). Int J Sport Nutr Exerc Metab 2003;13(1):112-6. PubMed
  11. Bauer BA, Elkin PL, Erickson D, Klee GG, Brennan MD. Symptomatic hyperthyroidism in a patient taking the dietary supplement tiratricol. Mayo Clin Proc 2002;77(6):587-90. PubMed
  12. Cohen-Lehman J, Charitou MM, Klein I. Tiratricol-induced periodic paralysis: a review of nutraceuticals affecting thyroid function. Endocr Pract 2011;17(4):610-5. 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 Tiratricol and Nivolumab Together: Common Questions

Is it safe to take Tiratricol with Nivolumab?
We do not list a known interaction between Tiratricol and Nivolumab. 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.
Do Tiratricol and Nivolumab have any of the same side effects?
Yes — our sources link each of them separately to 10 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Should I take Tiratricol and Nivolumab at the same time of day?
At least one FDA label for a product containing Nivolumab 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 Nivolumab on its own and move Tiratricol 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.
How was the Tiratricol and Nivolumab combination checked?
Interactions in our licensed database are recorded against drug classes. Nivolumab is filed under 1 classification, and Tiratricol has documented interactions with 4 drug classes — none of Nivolumab'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 Tiratricol interact with any other medications?
Yes. Tiratricol has 225 documented drug interactions in our database — Nivolumab 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 Nivolumab interact with any supplements?
Yes. Nivolumab has documented interactions with 1 supplement in our database — Tiratricol is not one of them. The Nivolumab 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

Tiratricol monograph Uses, safety profile, and every drug interaction in one place Nivolumab Injection drug information The full plain-English guide to this medication Nivolumab supplement interactions Every supplement checked against Nivolumab, 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 Nivolumab and Tiratricol?

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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.