Drug & supplement interaction

Tiratricol + Vismodegib

Vismodegib brand name: Erivedge.

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 Vismodegib 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 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 Vismodegib

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 Vismodegib 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 Vismodegib and Tiratricol? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Vismodegib

Interactions in our licensed database are recorded against drug classes, not just single drug names. Vismodegib is filed under 4 classifications — including cytochrome p450 2c19 (cyp2c19) inhibitors, cytochrome p450 2c9 (cyp2c9) inhibitors, p-glycoprotein substrates. 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 Vismodegib’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 — Vismodegib 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. Vismodegib)
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 Vismodegib 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.

  • Weight loss / Reduced appetite 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

    Vismodegib

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

  • Tiredness 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.

    Vismodegib

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

  • Diarrhea 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

    Vismodegib

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

Reported for Tiratricol but not commonly for Vismodegib: an irregular heartbeat, stomach pain, muscle weakness and a change in thyroid levels.

Effects for Vismodegib come from the ADVERSE REACTIONS section of its FDA label; effects for Tiratricol come from the Natural Medicines adverse-effect record, quoted above. 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

Everything else you take

See Every Supplement That Interacts With Vismodegib

This page covers Tiratricol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Vismodegib page lists 57 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), St. John's Wort (major), Bitter Melon (moderate), Black Pepper (moderate) and Bulbine Natalensis (moderate).

By severity: 2 major · 38 moderate · 17 minor.

From our pharmacist’s overview on the Vismodegib page

“St. John's wort can quietly undercut vismodegib (Erivedge), the pill for advanced basal cell carcinoma, by speeding up the gut pump that clears the drug from the body, and a cancer treatment that silently loses potency is the worst kind of interaction.”

Reviewed by 2 · Jul 18, 2026

Open the Vismodegib interaction page

How much people look this up

Where Tiratricol and Vismodegib 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

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

29 days ago today
Medication Vismodegib
Top 25%

#344 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 Vismodegib 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 Vismodegib

What Is Vismodegib Used For?

Brand name: Erivedge

Erivedge (vismodegib) is used to treat adults with basal cell carcinoma — the most common type of skin cancer — in two specific situations: when the cancer has spread to other parts of the body (metastatic basal cell carcinoma), or when it is locally advanced and has returned after surgery, or when surgery and radiation are not options.

It is not approved for use in children.

Most-Reported Side Effects for Vismodegib

From FAERS, the FDA’s public side-effect reporting system (8,850 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Muscle spasms 2,065 reports
Alopecia 1,401 reports
Ageusia 1,011 reports
Fatigue 970 reports
Dysgeusia 747 reports
See full Vismodegib 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 Vismodegib, 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 Vismodegib Together: Common Questions

Is it safe to take Tiratricol with Vismodegib?
We do not list a known interaction between Tiratricol and Vismodegib. 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 Vismodegib have any of the same side effects?
Yes — our sources link each of them separately to 4 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.
How was the Tiratricol and Vismodegib combination checked?
Interactions in our licensed database are recorded against drug classes. Vismodegib is filed under 4 classifications, and Tiratricol has documented interactions with 4 drug classes — none of Vismodegib'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 — Vismodegib 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 Vismodegib interact with any supplements?
Yes. Vismodegib has documented interactions with 57 supplements in our database — Tiratricol is not one of them. The Vismodegib 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 Vismodegib drug information The full plain-English guide to this medication Vismodegib supplement interactions Every supplement checked against Vismodegib, 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 Vismodegib 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.