Iodine + Propylthiouracil, PTU
Propylthiouracil, PTU brand name: Propylthiouracil.
Iodine has a moderate interaction with Propylthiouracil, PTU. Iodine might alter the effects of antithyroid drugs.
Read the full interaction reportIodine and Propylthiouracil, PTU
Here is the interaction we found between these two, with the evidence behind it.
ANTITHYROID DRUGS
Why this applies to Propylthiouracil, PTU
Propylthiouracil, PTU falls under ANTITHYROID DRUGS — the group Iodine interacts with.
Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking iodine while using antithyroid drugs could alter the effects of the antithyroid drugs.
Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..
Here's the thing to keep in mind: propylthiouracil (PTU) works by lowering how much thyroid hormone your overactive thyroid makes. Iodine is the raw material your thyroid uses to build those hormones, so adding a concentrated iodine supplement can work against what your PTU is trying to do. In some people it can throw thyroid levels off in either direction, which makes your medication harder to balance.
If your thyroid swings back up, you might notice a racing heart, shakiness, sweating, or feeling wound up again. This concern is mostly theoretical and based on how iodine behaves, not strong studies, and the iodine you get from food and iodized salt is usually fine. Still, before starting any high-dose iodine product, please check with your doctor or pharmacist first.
- Goodman GA, Rall TW, Nies AS, Taylor P. The Pharmacological Basis of Therapeutics, 9th ed.
- 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
What These Ratings Mean
Every interaction above is graded three ways — here’s the key to each label.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
- ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
- PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
- UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
- AHigh-quality meta-analysis (quantitative systematic review).
- BCase-control study.
- CConsensus.
- DAnecdotal evidence.
These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.
Iodine Also Interacts With Other Medications
Iodine has 6 moderate known drug interactions in our database — the Propylthiouracil, PTU one above is 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.
Questions About Iodine or Propylthiouracil, PTU
These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Iodine or Propylthiouracil, PTU, 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.
See Every Supplement That Interacts With Propylthiouracil, PTU
This page covers Iodine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Propylthiouracil, PTU page lists 64 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Ascophyllum Nodosum (moderate).
By severity: 4 major · 51 moderate · 9 minor.
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. Your product may carry other ingredients that interact with Propylthiouracil, PTU too, on top of Iodine — and those would not show on this page. Find your product and we’ll check every ingredient on its label:
Where Iodine and Propylthiouracil, PTU 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.
#19 of 1,452 supplements looked up here in the last 7 days
#985 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.
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.
About Propylthiouracil
What Is Propylthiouracil Used For?
Brand name: Propylthiouracil
Propylthiouracil tablets are used to treat hyperthyroidism — a condition where the thyroid gland makes too much thyroid hormone. It is specifically indicated for patients with Graves' disease or toxic multinodular goiter who cannot tolerate methimazole (another antithyroid drug) and for whom surgery or radioactive iodine is not a suitable option.
It is also used to bring thyroid hormone levels under control before a patient undergoes thyroidectomy (thyroid surgery) or radioactive iodine therapy, again in patients who cannot tolerate methimazole. Because of its serious liver risks, propylthiouracil is generally a second-choice treatment — used when other options are not appropriate.
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 “”.
6 interactions
No interaction 2,823 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 ›
- Testosterone ›
- Losartan Potassium ›
- Metoprolol ›
- Aspirin ›
- Ivermectin ›
- Rivaroxaban ›
- Rosuvastatin ›
- Escitalopram ›
- Tadalafil ›
- Acetaminophen ›
- Clopidogrel ›
- Valacyclovir ›
- Atorvastatin ›
- Docusate ›
- Hydroxyurea ›
- Abemaciclib ›
- Methamphetamine ›
- Ibuprofen ›
- Sumatriptan ›
- Semaglutide ›
- Tirzepatide ›
- Warfarin Sodium ›
- Prednisone ›
- Propranolol ›
- Lisdexamfetamine ›
- Acyclovir ›
- Bupropion ›
- Metformin ›
- Amoxicillin ›
- Lisinopril ›
- Bendamustine ›
- Amitriptyline ›
- Doxycycline ›
- Lamotrigine ›
- Fluoxetine ›
- Methotrexate ›
- Acetaminophen, Codeine ›
- Gabapentin ›
- Amphetamine ›
- Pregabalin ›
- Isotretinoin ›
- Dextroamphetamine ›
- Azithromycin ›
- Clonazepam ›
- Quetiapine ›
- Omeprazole ›
- Amlodipine Besylate ›
- Methylene Blue ›
- Duloxetine ›
- Letrozole ›
- Buspirone ›
- Citalopram ›
- Ciprofloxacin ›
- Naproxen ›
Showing the 60 most looked-up of 2,823 medications checked with no known interaction — see the full Iodine list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.
Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Taking Iodine and Propylthiouracil, PTU Together: Common Questions
Can you take Iodine with Propylthiouracil, PTU?
How serious is the Iodine and Propylthiouracil, PTU interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Still Have a Question About Propylthiouracil, PTU and Iodine?
Our pharmacists answer your medication & supplement questions — free.
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.