Public record

Methimazole: the public record

6 tables from US federal sources. Latest data date: Nov 11, 2026.

Each table is computed from the named federal dataset as of its data date; the method is under each one.

Label

FDA label facts for methimazole

The FDA label read for methimazole (Methimazole, application ANDA040547) was last revised on 2026-08-20. It carries no boxed warning. Of the 4 population sections checked, 3 are present: pregnancy, lactation, pediatric use.

FDA label facts for methimazole: the figures
MeasureValueNote
Label revision date2026-08-20
Label readMethimazoleANDA040547, generic application
Boxed warningNo
Pregnancy sectionPresent
Lactation sectionPresent
Pediatric use sectionPresent
Geriatric use sectionNot present

Source: FDA drug label via openFDA, viewable on NIH DailyMed, data as of Nov 11, 2026

How this was calculated

Selected the most recently revised prescription label for this single ingredient from an original manufacturer, preferring a brand-name application. Checked which sections exist and quoted headings and sentences exactly as printed.

Scope: One label: the newest prescription label for single-ingredient methimazole from an original manufacturer

Read from one label. Labels for other brands, strengths or forms of the same ingredient can differ. A missing section heading does not mean there is no guidance. Read the full label before relying on it.

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Approvals

FDA approval history for methimazole

The earliest FDA approval on file for a methimazole product is 1950-06-21. Drugs@FDA lists 12 applications for it and 53 approved supplements, the most recent on 2025-08-26.

FDA approval history for methimazole: the figures
MeasureValueNote
Earliest FDA approval on file1950-06-21
Applications with an approval on file12
New drug applications (NDA)1
Generic applications (ANDA)11
Approved supplements53label, manufacturing and efficacy changes
Most recent supplement approval2025-08-26
Sponsoring companies12

Source: FDA, Drugs@FDA, data as of Nov 11, 2026

How this was calculated

Selected applications with a product whose only active ingredient is this substance, then counted approved original and supplemental submissions. The earliest approved original submission is the first approval.

Scope: Applications with a single-ingredient methimazole product in Drugs@FDA, all sponsors and strengths

Older approvals can be missing dates, and tentative approvals are not counted. An approved application does not mean the product is currently marketed.

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Patents and generics

Patents and generic approvals for methimazole

The FDA Orange Book lists 11 approved generic applications for methimazole, the first approved on 2000-03-29. No unexpired patents are listed for it.

Patents and generic approvals for methimazole: the figures
MeasureValueNote
Brand-name applications (NDA)1
Approved generic applications (ANDA)11first approved 2000-03-29
Companies with a generic not marked discontinued8
Listed patents not yet expired0
Earliest approval date on filebefore 1982
Products not marked discontinued16 of 25

Source: FDA, Orange Book (Approved Drug Products with Therapeutic Equivalence Evaluations), data as of Oct 9, 2026

How this was calculated

Selected Orange Book products whose only active ingredient is this substance, then counted applications by type and the distinct patents and exclusivities listed against them. Expired patents are left out.

Scope: All single-ingredient methimazole products in the Orange Book, every brand and strength, files dated 2026-10-09

An approved generic or an expired patent does not show that a generic is on sale. Launch timing also depends on litigation, settlements and supply. Biologics and compounded products are not in the Orange Book.

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Medicare Part D

Medicare Part D spending on methimazole

Medicare Part D spending on methimazole products was $10.6M in 2024 across 943,504 claims, compared with $13.3M in 2023 (-20.2%). Average spending per claim was $11.24, before rebates.

Medicare Part D spending on methimazole: the figures
MeasureValue
Total spending, 2024$10.6M
Total spending, 2023$13.3M
Change in spending, 2023 to 2024-20.2%
Claims (prescription fills), 2024943,504
Average spending per claim, 2024$11.24

Source: CMS, Medicare Part D Spending by Drug, data as of 2024

How this was calculated

Summed total spending and claims over every brand and generic row with this generic name in the CMS file, using the Overall manufacturer rows. Combination products excluded. Average per claim is spending divided by claims.

Scope: Every single-ingredient methimazole product in Part D (Methimazole), 2024.

Gross drug cost before manufacturer rebates, so net cost is lower. Part D excludes some uses by law (for example erectile dysfunction, weight loss and hair growth), so claims reflect covered uses only. Compounded products are not included.

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Adverse event reports

Most reported events in FDA adverse event reports for methimazole

Through 2026-10-28, FDA had received 9,380 adverse event reports for methimazole, 7,048 of them marked serious by the reporter. The symptom terms named most often were fatigue (524), hyperthyroidism (489) and nausea (447).

Most reported events in FDA adverse event reports for methimazole: the figures
MeasureValueNote
All reports received9,380
Reports the reporter marked serious7,048death, hospitalisation, disability or similar outcome
Fatigue524 reports
Hyperthyroidism489 reports
Nausea447 reports
Diarrhoea419 reports
Headache382 reports

Source: FDA Adverse Event Reporting System (FAERS) via openFDA, data as of Oct 28, 2026

How this was calculated

Counted FAERS reports listing this active substance, then the reaction terms named most often. A report can name several reactions, and a term can describe the illness being treated and not an effect of the drug. Terms about product use or complaints rather than symptoms (for example drug ineffective) were left out of the list.

Scope: Reports where FDA recorded methimazole as a single-ingredient active substance (any brand), all years to 2026-10-28

FAERS reports are unverified and do not prove the drug caused the event. Reporting rises with use, publicity and lawsuits, so these counts cannot give rates or risks and cannot be compared between drugs.

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Clinical studies

Registered clinical studies of methimazole

ClinicalTrials.gov lists 40 registered studies that name methimazole as an intervention as of 2026-11-11. Of these, 4 are recruiting, 16 are completed and 4 are phase 3 studies.

Registered clinical studies of methimazole: the figures
MeasureValue
Registered studies40
Recruiting now4
Not yet recruiting2
Completed16
Terminated, withdrawn or suspended6
Phase 3 (including phase 2/3)4
Phase 2 (including phase 1/2)7
Phase 12

Source: NIH National Library of Medicine, ClinicalTrials.gov, data as of Nov 11, 2026

How this was calculated

Searched the ClinicalTrials.gov intervention field for the name, downloaded every matching record and counted by overall status and phase. Combined phases are counted under the higher phase. Phase not applicable covers observational, device and behavioural studies.

Scope: Studies whose intervention field matches methimazole, any condition, any country, all statuses

A registered study is not a result. Counts include studies where the drug is a comparator or background treatment, and studies that never finished or reported.

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Articles on Methimazole