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SHEET /m/methadone · PubChem CID 4095 · CAS 76-99-3 · REV 2026.07

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Methadone

from source

C21H27NO · 309.4 g/mol

Adanon · Algovetin · Amidone · Diaminon

What is Methadone?

A long-acting opioid used for opioid use disorder and for chronic pain. Its long stay in the body is the point: one dose covers a day. from source

Chemical familyAromaticsKetones
LeaderboardsBiggestDeadliest

Fig. 1 · 2D structure RDKit

SMILESCCC(=O)C(CC(C)N(C)C)(C1=CC=CC=C1)C2=CC=CC=C2

Where you'll find it

Dispensed on prescription, not sold on a shelf. See the rest of the prescription medicine group.

Relative acute toxicity from source

Animal study data · LD50

Reported LD50
86 mg/kg · moderately toxic
Species
rat
Route
oral

An LD50 describes acute toxicity under experimental conditions and is not a safe or dangerous dose for a person.

Toxicity & hazards

Toxicity · LD50

86 mg/kg · moderately toxic · LD50 rat oral from source

3 more reported values
  • 11 mg/kgLD50 · iv · rat
  • 18 mg/kgLD50 · other · rat
  • 30 mg/kgLD50 · other · rat
DangerToxicIrritantH300, H336, H412from source

Sources & methodology

PubChem CID
4095
Wikidata
Q179996
Structure
PubChem → RDKit
LD50
PubChem
Data refreshed

How MoleculeFinder sources and labels its data