Iodine + Pralsetinib
Pralsetinib brand name: Gavreto.
We found no known interaction between Iodine and Pralsetinib 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 Pralsetinib 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.
Iodine and Pralsetinib
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 Pralsetinib and Iodine 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.
Iodine safety at a glance
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.
Why No Interaction Is Listed for Pralsetinib
Interactions in our licensed database are recorded against drug classes, not just single drug names. Pralsetinib is filed under 5 classifications — including qt interval-prolonging drugs, p-glycoprotein substrates, hepatotoxic drugs. Iodine has documented interactions with 3 drug classes — the most serious being amiodarone (cordarone) (moderate), antithyroid drugs (moderate) and lithium (moderate) — and none of Pralsetinib’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.
Iodine Does Interact With Other Medications
Iodine has 7 moderate known drug interactions in our database — Pralsetinib isn’t one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Iodine
We haven’t checked that one against Iodine yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Iodine. Pick one to open its full report.
Iodine in Pregnancy & Breastfeeding
When used orally and appropriately. Iodine is safe in amounts that do not exceed the tolerable upper intake level (UL) of 1100 mcg daily in those 18 years and older or 900 mcg daily in those 14-18 years of age. Iodine needs increase during pregnancy and lactation and adequate intakes should begin as soon as a patient is aware of the pregnancy, or earlier in areas of potential deficiency. ...when used topically as a 2% solution. Iodine is an FDA-approved prescription product.
When used orally in doses exceeding the UL. Higher intake can cause thyroid dysfunction. Also, higher intakes during pregnancy cause increased iodine levels in breast milk and infant blood samples. Higher iodine intake during pregnancy has also been associated with an increased risk of congenital hypothyroidism and reduced mental and physical development in the offspring.
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
Some Pralsetinib Products Have a Food Rule — Iodine Should Not Break It
At least one FDA label for a product containing Pralsetinib says to take it on an empty stomach. Most supplements — Iodine included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Pralsetinib on its own and move Iodine 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 Pralsetinib 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.
( 2.1 , 14 ) The recommended dosage in adults and pediatric patients 12 years and older is 400 mg orally once daily on an empty stomach (no food intake for at least 2 hours before and at least 1 hour after taking GAVRETO).
From the Dosage and Administration section of the FDA label we read for Pralsetinib — 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.
What Pralsetinib Is Prescribed For, and What Iodine Has Been Studied For
These two come up together because they touch the same health topic — not because they do the same job. Pralsetinib is a prescription medicine with approved uses on its FDA label. Iodine is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.
Pralsetinib is prescribed for: Gavreto (pralsetinib) is used to treat adults with metastatic RET fusion-positive non-small cell lung cancer (NSCLC) — a type of lung cancer that has spread and carries a specific genetic alteration detected by an FDA-approved test. Gavreto is also approved for adults and children aged 12 and older with advanced or metastatic RET fusion-positive thyroid cancer who need systemic (whole-body) treatment and whose cancer no longer responds to radioactive iodine (when radioactive iodine is an appropriate option). This thyroid cancer use is under accelerated approval, meaning continued approval depends on results from confirmatory clinical trials.
Iodine has been studied for:
-
Thyroid cancer studied, not established Iodine has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows
Iodine for thyroid cancer
It is unclear if dietary iodine is associated with complications in patients with papillary thyroid cancer.
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 Pralsetinib on your own; if you are taking Iodine for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.
See Every Supplement That Interacts With Pralsetinib
This page covers Iodine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pralsetinib page lists 181 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).
By severity: 11 major · 134 moderate · 36 minor.
From our pharmacist’s overview on the Pralsetinib page
“With pralsetinib (Gavreto), a targeted therapy for RET-driven lung and thyroid cancers, I would treat this list as required reading rather than background noise. Most of the interactions change how much of the drug the body actually gets: grapefruit can push its levels higher, while St.”
Reviewed by 2 · Jul 18, 2026
Taking Iodine as Part of a Dietary Supplement Product? Check It for Interactions
We hold 14,226 real supplement products containing Iodine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Iodine. Even though Iodine itself has no known interaction with Pralsetinib, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:
Where Iodine and Pralsetinib 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.
#20 of 1,452 supplements looked up here in the last 7 days
#2,164 of 2,830 medications looked up here in the last 7 days
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 Iodine reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Iodine and Pralsetinib records this page draws on were last updated July 10, 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.
About Iodine
What is Iodine?
- Preventing iodine deficiency
- Supporting thyroid hormone production
- General energy and metabolism support
- Cognitive function
- Radiation emergency thyroid protection
Iodine is an essential mineral your body needs to make thyroid hormones, and most people get enough from iodized salt, dairy, and seafood. Supplements help when you are truly deficient, but taking too much can harm the thyroid, so high-dose products should only be used under medical supervision.
Mineral (element) · Tablets, capsules, liquid drops (Lugol's solution), potassium iodide (KI) tablets, kelp/seaweed supplements, iodized salt
An interaction check asks whether these two react with each other — it does not ask whether Iodine is a good idea for someone in your situation. Here is what our Iodine record says about it on its own.
Iodine: dosing
National health agencies have set general daily intake recommendations for iodine, and most healthy adults can meet their needs through a balanced diet and iodized salt.Standalone iodine products, such as Lugol's solution or high-dose tablets, can contain many times the amount your body needs in a day. These should not be used casually.
From our Iodine monograph — the full record covers uses, side effects and every documented interaction.
About Pralsetinib
What Is Pralsetinib Used For?
Brand name: Gavreto
Gavreto (pralsetinib) is used to treat adults with metastatic RET fusion-positive non-small cell lung cancer (NSCLC) — a type of lung cancer that has spread and carries a specific genetic alteration detected by an FDA-approved test.
Gavreto is also approved for adults and children aged 12 and older with advanced or metastatic RET fusion-positive thyroid cancer who need systemic (whole-body) treatment and whose cancer no longer responds to radioactive iodine (when radioactive iodine is an appropriate option). This thyroid cancer use is under accelerated approval, meaning continued approval depends on results from confirmatory clinical trials.
Most-Reported Side Effects for Pralsetinib
From FAERS, the FDA’s public side-effect reporting system (1,788 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
Other Drugs & Iodine
Browse every other medication we’ve checked against Iodine — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
7 interactions
No interaction 2,822 drugs checked — show the list
We also checked Iodine against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Losartan Potassium ›
- Testosterone ›
- Ivermectin ›
- Abemaciclib ›
- Aspirin ›
- Metoprolol ›
- Acetaminophen ›
- Rosuvastatin ›
- Rivaroxaban ›
- Escitalopram ›
- Clopidogrel ›
- Atorvastatin ›
- Tadalafil ›
- Docusate ›
- Tirzepatide ›
- Ibuprofen ›
- Methamphetamine ›
- Hydroxyurea ›
- Warfarin Sodium ›
- Valacyclovir ›
- Sumatriptan ›
- Semaglutide ›
- Prednisone ›
- Lisdexamfetamine ›
- Propranolol ›
- Metformin ›
- Amitriptyline ›
- Amoxicillin ›
- Lisinopril ›
- Isotretinoin ›
- Methotrexate ›
- Amlodipine Besylate ›
- Bendamustine ›
- Bupropion ›
- Amphetamine ›
- Fluoxetine ›
- Doxycycline ›
- Acyclovir ›
- Azithromycin ›
- Lamotrigine ›
- Pregabalin ›
- Dextroamphetamine ›
- Gabapentin ›
- Acetaminophen, Codeine ›
- Quetiapine ›
- Clonazepam ›
- Levothyroxine, Liothyronine ›
- Naproxen ›
- Omeprazole ›
- Letrozole ›
- Methylene Blue ›
- Duloxetine ›
- Buspirone ›
- Citalopram ›
Showing the 60 most looked-up of 2,822 medications checked with no known interaction — see the full Iodine list.
Iodine References
The 26 references that drive our Iodine 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.
- McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
- Goodman GA, Rall TW, Nies AS, Taylor P. The Pharmacological Basis of Therapeutics, 9th ed.
- Ghent WR, Eskin BA, Low DA, Hill LP. Iodine replacement in fibrocystic disease of the breast. Can J Surg 1993;36:453-60.
- Potassium iodide for nuclear exposure. Pharmacist's Letter/Prescriber's Letter 2001;17(12):171214.
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
- Cabezas C, Bustamante B, Holgado W, Begue RE. Treatment of cutaneous sporotrichosis with one daily dose of potassium iodide. Pediatr Infect Dis J 1996;15:352-4. PubMed
- Sterling JB, Heymann WR. Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications. J Am Acad Dermatol 2000;43:691-7. PubMed
- Yarrington CD, Pearce EN. Dietary iodine in pregnancy and postpartum. Clin Obstet Gynecol 2011;54:459-70. PubMed
- Goel, S., Mandhani, A., Srivastava, A., Kapoor, R., Gogoi, S., Kumar, A., and Bhandari, M. Is povidone iodine an alternative to silver nitrate for renal pelvic instillation sclerotherapy in chyluria? BJU.Int 2004;94(7):1082-1085. PubMed
- Teng, W., Shan, Z., Teng, X., Guan, H., Li, Y., Teng, D., Jin, Y., Yu, X., Fan, C., Chong, W., Yang, F., Dai, H., Yu, Y., Li, J., Chen, Y., Zhao, D., Shi, X., Hu, F., Mao, J., Gu, X., Yang, R., Tong, Y., Wang, W., Gao, T., and Li, C. Effect of iodine int
- Crawford, B. A., Cowell, C. T., Emder, P. J., Learoyd, D. L., Chua, E. L., Sinn, J., and Jack, M. M. Iodine toxicity from soy milk and seaweed ingestion is associated with serious thyroid dysfunction. Med J Aust. 10-4-2010;193(7):413-415. PubMed
- Ohkuma, M. Molluscum contagiosum treated with iodine solution and salicylic acid plaster. Int J Dermatol. 1990;29(6):443-445. PubMed
- Connelly KJ, Boston BA, Pearce EN, Sesser D, Snyder D, Braverman LE, Pino S, LaFranchi SH. Congenital hypothyroidism caused by excess prenatal maternal iodine ingestion. J Pediatr. 2012 Oct;161(4):760-2. PubMed
- Kasahara T, Narumi S, Okasora K, Takaya R, Tamai H, Hasegawa T. Delayed onset congenital hypothyroidism in a patient with DUOX2 mutations and maternal iodine excess. Am J Med Genet A. 2013 Jan;161A(1):214-7.
- Murcia M, Rebagliato M, Iñiguez C, Lopez-Espinosa MJ, Estarlich M, Plaza B, Barona-Vilar C, Espada M, Vioque J, Ballester F. Effect of iodine supplementation during pregnancy on infant neurodevelopment at 1 year of age. Am J Epidemiol. 2011 Apr 1;173(7):8 PubMed
- Sang Z, Wang PP, Yao Z, Shen J, Halfyard B, Tan L, Zhao N, Wu Y, Gao S, Tan J, Liu J, Chen Z, Zhang W. Exploration of the safe upper level of iodine intake in euthyroid Chinese adults: a randomized double-blind trial. Am J Clin Nutr. 2012 Feb;95(2):367-73 PubMed
- Speeckaert MM, Speeckaert R, Wierckx K, Delanghe JR, Kaufman JM. Value and pitfalls in iodine fortification and supplementation in the 21st century. Br J Nutr. 2011 Oct;106(7):964-73. PubMed
- Yun SE, Kang Y, Bae EJ, Hwang K, Jang HN, Cho HS, Chang SH, Park DJ. Iodine-induced thyrotoxic hypokalemic paralysis after ingestion of Salicornia herbace. Ren Fail. 2014 Apr;36(3):461-3.
- Iodine Hypersensitivity. Pharmacist's Letter/Prescriber's Letter 2011; 27(5):270504.
- Hammel JA, Selby JC. Pustular eruption in a patient with cancer treated with complementary and alternative medicine. JAMA Dermatology 2017 October; E1. doi: 10.1001/jamadermatol.2017.3749. [Epub ahead of print] PubMed
- Gil GS, Smith BW, Guerra JR, Williams WT. Acute Delirium in a Hypothyroid Patient Precipitated by Iodine Supplements Use. Am J Ther. 2018;25(6):e717-e718. PubMed
- Hamby T, Kunnel N, Dallas JS, Wilson DP. Maternal iodine excess: an uncommon cause of acquired neonatal hypothyroidism. J Pediatr Endocrinol Metab. 2018;31(9):1061-1064. PubMed
- Censi S, Watutantrige-Fernando S, Groccia G, et al. The Effects of Iodine Supplementation in Pregnancy on Iodine Status, Thyroglobulin Levels and Thyroid Function Parameters: Results from a Randomized Controlled Clinical Trial in a Mild-to-Moderate Iodine
- Rovner MS, Wolf BJ, Rubin M, et al. Instillation of 5% Povidone-Iodine Ophthalmic Drops Decreases the Respiratory Rate in Children Undergoing Strabismus Surgery: A Randomized Controlled Trial. J Pediatr Ophthalmol Strabismus. 2019;56(6):378-382. PubMed
- Guenezan J, Garcia M, Strasters D, et al. Povidone Iodine Mouthwash, Gargle, and Nasal Spray to Reduce Nasopharyngeal Viral Load in Patients With COVID-19: A Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg. 2021;147(4):400-401. PubMed
- Li F, Wan S, Zhang L, et al. A Meta-Analysis of the Effect of Iodine Excess on the Intellectual Development of Children in Areas with High Iodine Levels in their Drinking Water. Biol Trace Elem Res 2022;200(4):1580-1590. 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.
Taking Iodine and Pralsetinib Together: Common Questions
Is it safe to take Iodine with Pralsetinib?
Do Iodine and Pralsetinib have any of the same side effects?
Should I take Iodine and Pralsetinib at the same time of day?
Are Iodine and Pralsetinib used for the same thing?
How was the Iodine and Pralsetinib combination checked?
Does Iodine interact with any other medications?
Does Pralsetinib interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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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.