Iodine + Methenamine Mandelate
Methenamine Mandelate brand names: Mandelamine, Methimazole.
Iodine has a moderate interaction with Methenamine Mandelate. Iodine might alter the effects of antithyroid drugs.
Read the full interaction reportIodine and Methenamine Mandelate
Here is the interaction we found between these two, with the evidence behind it.
ANTITHYROID DRUGS
Why this applies to Methenamine Mandelate
Methenamine Mandelate 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..
Quick heads-up on names here: the drug you asked about is listed as methimazole (brand Tapazole), which is an antithyroid medicine used to calm down an overactive thyroid. Its whole job is to slow your thyroid's hormone production, so symptoms like a racing heart, shakiness, weight loss, and feeling overheated settle down.
Iodine is the raw material your thyroid uses to make those hormones. So adding iodine, especially in concentrated supplement doses, can work against methimazole and make it harder to keep your thyroid controlled. This is a theoretical concern based on how these two behave, not something proven in big studies, and the everyday iodine in food or iodized salt is unlikely to be the problem. Before adding any iodine supplement, please check with your doctor or pharmacist so they can keep an eye on your thyroid levels.
- 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 Methenamine Mandelate 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.
See Every Supplement That Interacts With Methenamine Mandelate
This page covers Iodine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methenamine Mandelate page lists 91 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 · 77 moderate · 10 minor.
From our pharmacist’s overview on the Methenamine Mandelate page
“People take methenamine mandelate (Mandelamine) day after day to keep urinary tract infections at bay, and that long habit is exactly why the 91 supplements on this page deserve genuine vigilance. Four carry a major rating, and most of those point at the liver: Siberian cocklebur has been linked to outright liver failure, and heavy bee…”
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. Your product may carry other ingredients that interact with Methenamine Mandelate 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 Methenamine Mandelate 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
#1,467 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 Methimazole
What Is Methimazole Used For?
Brand names: Mandelamine, Methimazole
Methimazole tablets are used in adults and children with hyperthyroidism (an overactive thyroid) due to Graves' disease or toxic multinodular goiter when surgery or radioactive iodine is not the right option. They work to lower thyroid hormone levels and ease symptoms.
Methimazole tablets are also used to bring thyroid hormone levels down before a patient undergoes thyroidectomy (thyroid surgery) or radioactive iodine treatment, making those procedures safer.
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 ›
- Acetaminophen ›
- Tadalafil ›
- Clopidogrel ›
- Atorvastatin ›
- Docusate ›
- Abemaciclib ›
- Hydroxyurea ›
- Valacyclovir ›
- Methamphetamine ›
- Ibuprofen ›
- Semaglutide ›
- Sumatriptan ›
- Warfarin Sodium ›
- Tirzepatide ›
- Prednisone ›
- Propranolol ›
- Bupropion ›
- Lisdexamfetamine ›
- Metformin ›
- Amoxicillin ›
- Lisinopril ›
- Acyclovir ›
- Bendamustine ›
- Amitriptyline ›
- Doxycycline ›
- Methotrexate ›
- Lamotrigine ›
- Fluoxetine ›
- Amphetamine ›
- Acetaminophen, Codeine ›
- Pregabalin ›
- Gabapentin ›
- Dextroamphetamine ›
- Azithromycin ›
- Isotretinoin ›
- Methylene Blue ›
- Clonazepam ›
- Omeprazole ›
- Quetiapine ›
- Amlodipine Besylate ›
- Duloxetine ›
- Letrozole ›
- Buspirone ›
- Naproxen ›
- Citalopram ›
- Ciprofloxacin ›
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
Methenamine Mandelate Is Linked to Lower Levels of 7 Nutrients
Natural Medicines records Methenamine Mandelate as a medicine that can lower these. This is not an interaction with Iodine — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Read the full Methenamine Mandelate nutrient depletion report ›
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Iodine and Methenamine Mandelate Together: Common Questions
Can you take Iodine with Methenamine Mandelate?
How serious is the Iodine and Methenamine Mandelate interaction?
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.