Last reviewed 2026-05-24 · How we verify

Iothiouracil (IODOTHIOURACIL)

Phase 2 active Small molecule ✓ Verified May 2026

Iothiouracil (generic name: IODOTHIOURACIL) is a iodothiouracil drug. It is currently in Phase 2 development.

Iothiouracil works by inhibiting the synthesis of thyroid hormones.

Iothiouracil is a small molecule with synonyms including IODOTHIOURACIL, IODOTIOURACILO, and IOTHIOURACIL.

Likelihood of approval

15.3% vs 15.3% industry baseline

If approved by FDA: likely 2031–2034

Steps remaining: Phase 3 → NDA/BLA submission

Confidence: Medium

Why this estimate

Baseline phase 2 → approval rate +15.3pp
Industry-wide phase 2 drugs reach approval ~15.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas).

Predicted approval windows by jurisdiction (conditional on FDA approval)

Regulator	Country	Likely year	Lag vs FDA
FDA	US	2031–2034	—
EMA	EU	2032–2035	+0.7 yr
MHRA	GB	2032–2035	+0.7 yr
Health Canada	CA	2032–2036	+0.9 yr
TGA	AU	2032–2036	+1.2 yr
PMDA	JP	2032–2036	+1.5 yr
NMPA	CN	2033–2037	+2.3 yr
MFDS	KR	2032–2036	+1.4 yr
CDSCO	IN	2032–2037	+1.8 yr
ANVISA	BR	2033–2037	+2.3 yr

Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).

Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.

At a glance

Generic name	IODOTHIOURACIL
Drug class	iodothiouracil
Modality	Small molecule
Therapeutic area	Metabolic
Phase	Phase 2

Mechanism of action

Think of it like a brake on a car - iodothiouracil puts the brakes on the thyroid gland's ability to make thyroid hormones, which are like the 'gas pedal' for the body's metabolism. By slowing down hormone production, iodothiouracil can help reduce the symptoms of hyperthyroidism, a condition where the thyroid gland produces too many hormones.

Approved indications

No approved indications tracked.

Common side effects

No common side effects on file.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

Iothiouracil CI brief — competitive landscape report
Iothiouracil updates RSS · CI watch RSS

Frequently asked questions about Iothiouracil

What is Iothiouracil?

Iothiouracil (IODOTHIOURACIL) is a iodothiouracil drug.

How does Iothiouracil work?

Iothiouracil works by inhibiting the synthesis of thyroid hormones.

What is the generic name of Iothiouracil?

IODOTHIOURACIL is the generic (nonproprietary) name of Iothiouracil.

What drug class is Iothiouracil in?

Iothiouracil belongs to the iodothiouracil class. See all iodothiouracil drugs at /class/iodothiouracil.

What development phase is Iothiouracil in?

Iothiouracil is in Phase 2.

Drug class: All iodothiouracil drugs
Therapeutic area: All drugs in Metabolic

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing