SHEET /m/acetaminophen · PubChem CID 1983 · CAS 103-90-2 · REV 2026.07
Acetaminophen
from sourceC8H9NO2 · 151.16 g/mol
paracetamol · p-acetylaminophenol · p-hydroxyacetanilide · p-acetamidophenol
Also sold as Tylenol from source
What is Acetaminophen?
The pain and fever reliever sold as Tylenol and Panadol, and the most-visited page on MoleculeFinder. Outside the US it is usually called paracetamol. from source
Fig. 1 · 2D structure RDKit
CC(=O)NC1=CC=C(C=C1)OWhere you'll find it
Curated by MoleculeFinder from source
Still in the system computed
For a typical adult, Acetaminophen clears on a half-life of about 2 h: every 2 hours, half of what is left is gone. Try an amount:
An illustration of half-life, not a prediction of anyone's level.
Relative acute toxicity from source
Animal study data · LD50
- Reported LD50
- 1,944 mg/kg · low toxicity
- Species
- rat
- Route
- oral
An LD50 describes acute toxicity under experimental conditions and is not a safe or dangerous dose for a person.
Signature properties
Toxicity & hazards
Toxicity · LD50
1,944 mg/kg · low toxicity · LD50 rat oral from source
5 more reported values
- 338 mg/kgLD50 · oral · mouse
- 2,400 mg/kgLD50 · oral · rat
- 310 mg/kgLD50 · other · mouse
- 367 mg/kgLD50 · other · mouse
- 1,205 mg/kgLD50 · other · rat
Keep roaming
Where Acetaminophen leads
Compare with
Acetaminophen, sold as Tylenol or paracetamol, is the most common drug in the medicine cabinet and, in overdose, the leading cause of acute liver failure. It eases pain and fever without the stomach irritation of the NSAIDs, but its safety margin is narrower than most people assume.