Last reviewed 2026-06-01 · How we verify

Mepidon (NORMETHADONE)

Phase 2 active Small molecule ✓ Verified Jun 2026

Mepidon (generic name: NORMETHADONE) is a normethadone drug. It is currently in Phase 2 development.

Mepidon works by binding to the mu-type opioid receptor in the brain, which can help to reduce pain perception.

Mepidon is a small molecule with synonyms including EUCOPON, HOECHST 10582, and ISOMETHADONE I.

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	NORMETHADONE
Drug class	normethadone
Target	D(2) dopamine receptor, D(3) dopamine receptor, Mu-type opioid receptor
Modality	Small molecule
Therapeutic area	Pain
Phase	Phase 2

Mechanism of action

Imagine your brain has special locks that control how much pain you feel. Mepidon is a key that fits into one of these locks, which helps to turn down the pain signal. This can provide relief from pain, but it's a complex process that involves many different parts of the brain and body.

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:

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

Frequently asked questions about Mepidon

What is Mepidon?

Mepidon (NORMETHADONE) is a normethadone drug.

How does Mepidon work?

Mepidon works by binding to the mu-type opioid receptor in the brain, which can help to reduce pain perception.

What is the generic name of Mepidon?

NORMETHADONE is the generic (nonproprietary) name of Mepidon.

What drug class is Mepidon in?

Mepidon belongs to the normethadone class. See all normethadone drugs at /class/normethadone.

What development phase is Mepidon in?

Mepidon is in Phase 2.

What does Mepidon target?

Mepidon targets D(2) dopamine receptor, D(3) dopamine receptor, Mu-type opioid receptor and is a normethadone.

Drug class: All normethadone drugs
Target: All drugs targeting D(2) dopamine receptor, D(3) dopamine receptor, Mu-type opioid receptor
Therapeutic area: All drugs in Pain

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