Methimazole

Summary

Methimazole (CHEMBL1515) is an approved small-molecule antithyroid drug (ATC H03BB52) targeting TPO and TAS2R38; indicated across 8 conditions including thyroid gland disorder and hyperthyroidism.

At a glance

• Status: Approved (max clinical phase 4)
• Modality: Small molecule
• ATC class: H03BB52 (+1 more)
• Targets: 2 (TPO, TAS2R38)
• Indications: 8 conditions
• Clinical trials: 23
• Chemistry: 114.17 Da · C4H6N2S

Identifiers

Drug identity and classification

Field	Value
ChEMBL ID	CHEMBL1515
Name	Methimazole
Type	Small molecule
Max phase	4
FDA approved	yes
PubChem CID	1349907
ChEBI	CHEBI:50673
ATC	H03BB52, H03BB02
Molecular formula	C4H6N2S
Molecular weight	114.17
InChIKey	PMRYVIKBURPHAH-UHFFFAOYSA-N

SMILES: CN1C=CNC1=S

IUPAC name: 3-methyl-1H-imidazole-2-thione

ChEBI definition: A member of the class of imidazoles that it imidazole-2-thione in which a methyl group replaces the hydrogen which is attached to a nitrogen.

Pharmacological roles (ChEBI): antithyroid drug.

Also known as: Favistan, Mercaptizole, Methimazole, NSC-38608, Tapazole, Thiamazol, Thiamazole, Tiamazol, Methimazol, methimazole, SID11112158, SID8139973

Patent coverage: 6,129 distinct patent families (18,943 SureChEMBL compound mentions), from 2 matched compound structure(s). Mentions count patents naming the compound (not distinct inventions), so promiscuous / reference molecules inflate the mention figure — families are the dedup metric.

Targets

Targets

Primary targets (GtoPdb curated mechanism): the Cancer dependency column is the DepMap CRISPR fitness signal (% of screened cell lines dependent on the target).

Gene	Target	Action	pAffinity	Cancer dependency	UniProt
TPO	thyroid peroxidase	Inhibition			P07202
TAS2R38	TAS2R38	Agonist	4.01	0.1%	P59533

Broader ChEMBL bioactivity targets: 10 (assay-derived). Sample: Nuclear receptor ROR-gamma, Survival motor neuron protein, Prelamin-A/C, 4’-phosphopantetheinyl transferase ffp, Menin/Histone-lysine N-methyltransferase MLL, Prostaglandin G/H synthase 1, Lactoperoxidase, Aldehyde dehydrogenase 1A1, Dopamine beta-hydroxylase, Lactoperoxidase.

Bioactivity

ChEMBL activities: 5 potent at pChembl ≥ 5 of 12 total. Top 30 by potency (10 = 0.1 nM, 6 = 1 µM):

Target	pChembl	Type	Value	Unit	Activity ID
LMNA	8.7	Potency	2	nM	CHEMBL_ACT_3666151
LPO	6.29	IC50	510	nM	CHEMBL_ACT_25881959
PTGS1	6.27	AC50	541.1	nM	CHEMBL_ACT_25205630
SMN1	6.15	Potency	707.9	nM	CHEMBL_ACT_3869996
P80025	5.08	IC50	8400	nM	CHEMBL_ACT_12579897

Target pathways

Aggregated over 2 target gene(s): TPO, TAS2R38.

Top Reactome pathways

10 total, by targets touching each:

Pathway	Targets	Genes
Signal Transduction	1	TAS2R38
Thyroxine biosynthesis	1	TPO
Signaling by GPCR	1	TAS2R38
GPCR downstream signalling	1	TAS2R38
G alpha (i) signalling events	1	TAS2R38
Class C/3 (Metabotropic glutamate/pheromone receptors)	1	TAS2R38
GPCR ligand binding	1	TAS2R38
Sensory Perception	1	TAS2R38
Sensory perception of taste	1	TAS2R38
Sensory perception of sweet, bitter, and umami (glutamate) taste	1	TAS2R38

Dominant GO biological processes

GO term	Targets
thyroid hormone generation	1
response to oxidative stress	1
embryonic hemopoiesis	1
hormone biosynthetic process	1
hydrogen peroxide catabolic process	1
cellular oxidant detoxification	1
detection of chemical stimulus involved in sensory perception of bitter taste	1
signal transduction	1
G protein-coupled receptor signaling pathway	1
sensory perception of taste	1

Indications & clinical

Indications

8 indications (2 at ChEMBL trial phase 4). Phase below is the highest clinical-trial phase recorded for this drug against each disease — not the molecule’s overall approval status (that is in the Summary).

Indication	Trial phase	MONDO	EFO
thyroid gland disorder	4	MONDO:0003240	HP:0000820
hyperthyroidism	4	MONDO:0004425	EFO:0009189
dermatomyositis	2	MONDO:0016367	EFO:0000398
glioblastoma	2	MONDO:0018177	EFO:0000519
polymyositis	2	MONDO:0019127	EFO:0003063
Graves disease	2	MONDO:0005364	EFO:0004237
gliosarcoma	0	MONDO:0016681	EFO:1001465

1 further indication record had no mapped disease name (EFO/MeSH-only) or were duplicates, and are omitted.

Clinical trials

Total trials: 23.

Phase distribution

Phase	Trials
Not specified	8
PHASE4	5
PHASE2	4
PHASE3	2
PHASE2/PHASE3	1
PHASE1/PHASE2	1
PHASE1	1
EARLY_PHASE1	1

Top trials by phase / activity

NCT	Phase	Status	Title
NCT05461820	PHASE4	RECRUITING	Effects of Different Treatment Schemes on the Regulation and Recurrence of Graves’ Disease
NCT00150124	PHASE4	COMPLETED	Block-replacement Therapy During Radioiodine Therapy
NCT00150137	PHASE4	COMPLETED	Antithyroid Drugs During Radioiodine Therapy
NCT01458600	PHASE4	COMPLETED	Adjuvant Treatment of Graves´ Ophthalmopathy With NSAID (aGO Study)
NCT01849861	PHASE4	UNKNOWN	Cardiopulmonary Capacity in Elderly With Different Ranges of Serum Thyroid Stimulating Hormone
NCT06068179	PHASE2/PHASE3	RECRUITING	Graves’ Disease Remission Study: MycoMeth Combo
NCT04776993	PHASE3	UNKNOWN	A Conservative vs an Ablative Approach for Treatment of Hyperthyroidism in Patients With Graves’ Orbitopathy
NCT05118542	PHASE3	COMPLETED	Effect of Hyperthyroidism and Its Treatment in Graves’ Disease to Early Marker of Atherosclerosis
NCT05607407	PHASE2	RECRUITING	Methimazole in Patients With Progressive Glioblastoma
NCT07369063	PHASE2	RECRUITING	Impact of Vitamin D Therapy on Thyroid Function and Antibody Levels in Pediatric Graves’ Disease
NCT00001421	PHASE2	COMPLETED	Methimazole to Treat Polymyositis and Dermatomyositis
NCT00150111	PHASE1/PHASE2	COMPLETED	Rituximab in the Treatment of Graves’ Disease
NCT06240455	PHASE2	SUSPENDED	Phase 2 Study to Assess Efficacy & Safety of WP1302 Prevent Relapse of MMI w/Draw in Subj. w/ Graves’ dz
NCT04346901	PHASE1	COMPLETED	Comparative Study of mMASI Before and After Hyperthyroid Therapy in Hyperthyroid Subjects With Melasma
NCT05017610	EARLY_PHASE1	WITHDRAWN	Inducing a Hypothyroxinemic State in Patients With Recurrent Glioblastoma or Gliosarcoma
NCT01560299	Not specified	COMPLETED	Evaluation of Optimal Time of Methimazole Discontinuation Before Radio-iodine Therapy in Hyperthyroid Grave’s Patients
NCT01893450	Not specified	TERMINATED	Bromocriptine and Pentoxifylline in Ophthalmopathy Autoimmune Treatment
NCT02376088	Not specified	COMPLETED	Characteristics of Islet β-cell Functions in Chinese Patients With Graves’ Disease
NCT02727738	Not specified	COMPLETED	Treatment of Graves’ Hyperthyroidism With Selenium Plus Methimazole
NCT03390582	Not specified	UNKNOWN	Gut Microbiota is Associated With Autoimmune Thyroid Disease
NCT03433352	Not specified	UNKNOWN	Intestinal Microbiota and Treatment of GD
NCT03447093	Not specified	UNKNOWN	The Oral Microbiota is Associated With Autoimmune Thyroiditis
NCT05964452	Not specified	TERMINATED	Efficacy of Methimazole Dosing Algorithm

Clinical evidence (CIViC)

No CIViC predictive evidence (expected for non-precision-medicine drugs).

Pharmacology

Pharmacogenomics

No CPIC/DPWG dosing guideline, but PharmGKB curates 1 clinical and 6 variant annotation(s) for this drug (gene-keyed; see PharmGKB).

Related molecules

Related molecules

Molecules sharing ≥1 of this drug’s curated primary targets, merged from two biobtree sources and ranked by shared-target count, then clinical phase: ChEMBL clinical-stage candidates (development phase ≥2) and PubChem drug-class bioactivity (approved / known drugs acting on the target). Deduplicated by drug name; the drug’s own salt forms are excluded. Note: for a drug with few primary targets a shared-target match can reflect off-target / promiscuous binding rather than the same therapeutic mechanism — the phase ordering surfaces bona-fide therapeutics first.

3 molecules share ≥1 primary target. Top 3 by shared-target count:

Molecule	Source	Status	Shared targets
PROPYLTHIOURACIL	ChEMBL + PubChem	Phase 4 (approved)	TAS2R38, TPO
ISOPROTERENOL	ChEMBL	Phase 4 (approved)	TAS2R38
MITIPERSTAT	ChEMBL	Phase 2	TPO