Methimazole

Sold as Tapazole. Every FDA application for this active ingredient: 1 branded and 11 generic.

As of Nov 13, 2026, FDA lists 12 applications for Methimazole (sold as Tapazole), first approved Jun 21, 1950, with 0 new uses approved and 0 published complete response letters.

First approved: Jun 21, 1950
Applications: 12
New uses approved: 0
Complete response letters: 0
Medicare spending, 2025: $10.8M

Medicare Spending

CMS Part D and Part B, 2025, before manufacturer rebates; matched by generic name

Product	Part	Spending, 2025	Change	Beneficiaries
Methimazole	Part D	$10.8M	+2%	237,638

Clinical Trials

7 open or ongoing studies name this ingredient as an intervention, including as a comparator; newest first. See all


AI-Based Wearable Monitoring (Glandy HYPER) for Antithyroid Drug Dose Adjustment in Graves' DiseaseHyperthyroidism, Graves Disease · THYROSCOPE INC.	Not applicable	Not yet recruiting	Oct 5, 2026
Impact of Vitamin D Therapy on Thyroid Function and Antibody Levels in Pediatric Graves' DiseaseGraves Disease, Graves' Disease · Northwell Health	Phase 2	Active, not recruiting	Jan 27, 2026
A Clinical Follow-up Study on Drug Therapy for Graves' Disease Patients in ChinaGraves´ Disease · First Hospital of China Medical University	—	Recruiting	Jun 27, 2025
Prospective Evaluation of OptiThyDoseThyroid Diseases, Congenital Hypothyroidism · University Children's Hospital Basel	Not applicable	Recruiting	Mar 7, 2025
A Clinical Study of Hyperthyroidism in ChildrenHyperthyroidism · Shengjing Hospital	—	Recruiting	Aug 26, 2024
Iodine Supplementation in Graves' HyperthyroidismGraves Disease, Hyperthyroidism · Shandong Provincial Hospital	Not applicable	Not yet recruiting	Aug 6, 2024
Effects of Different Treatment Schemes on the Regulation and Recurrence of Graves' DiseaseGraves Disease, Relapse · The First Affiliated Hospital with Nanjing Medical University	Phase 4	Recruiting	Jul 18, 2022

Applications

NDAs, BLAs and generic ANDAs for this ingredient, oldest first; each opens its full history


Jun 21, 1950	TapazoleNDA 7517 · New molecular entity	King Pharms	17	Discontinued
Mar 29, 2000	MethimazoleANDA 40350	Mylan	10	Marketed
Mar 31, 2000	TapazoleANDA 40320	King Pharms LLC	6	Discontinued
Mar 27, 2001	MethimazoleANDA 40411	Chartwell Rx	8	Marketed
Feb 18, 2005	MethimazoleANDA 40547	Aiping Pharm Inc	2	Marketed
Jul 12, 2005	MethimazoleANDA 40619	Discovery Therap	2	Discontinued
Sep 25, 2007	MethimazoleANDA 40870	Sun Pharm Inds Inc	2	Discontinued
Dec 14, 2007	MethimazoleANDA 40734	Heritage Pharma	3	Marketed
Mar 7, 2012	MethimazoleANDA 202068	Rising	3	Marketed
May 24, 2023	MethimazoleANDA 209827	Macleods Pharms	0	Marketed
Sep 25, 2023	MethimazoleANDA 218149	Bionpharma	0	Marketed
Feb 5, 2025	MethimazoleANDA 218830	Square Pharms PLC	0	Marketed

Applications, approvals and products come from FDA's Drugs@FDA data files, refreshed weekly, grouped by active ingredient as FDA spells it. Complete response letters are FDA's published letters. Medicare spending is CMS's Part D and Part B dashboard, matched to this ingredient by generic name; shortages are FDA's shortage list, matched by application number; clinical trials are ClinicalTrials.gov studies naming the ingredient as an intervention, refreshed daily; safety programs are FDA's REMS list, matched by application number or, for shared programs, by ingredient. Drugs@FDA