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SHEET /m/cyclobenzaprine · PubChem CID 2895 · CAS 303-53-7 · REV 2026.07

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Cyclobenzaprine

from source

C20H21N · 275.4 g/mol

Fexmid · Lisseril · Proeptatriene · Proheptatrien

What is Cyclobenzaprine?

A muscle relaxant sold as Flexeril, used short term for muscle spasm. Its skeleton is a tricyclic antidepressant's, one double bond apart from amitriptyline. from source

Chemical familyAromatics
LeaderboardsBiggestDeadliest

Fig. 1 · 2D structure RDKit

SMILESCN(C)CCC=C1C2=CC=CC=C2C=CC3=CC=CC=C31

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
425 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.

Toxicity & hazards

Toxicity · LD50

425 mg/kg · low toxicity · LD50 rat oral from source

4 more reported values
  • 250 mg/kgLD50 · oral · mouse
  • 338 mg/kgLD50 · oral · mouse
  • 36 mg/kgLD50 · iv · mouse
  • 90 mg/kgLD50 · other · mouse
DangerToxicIrritantH301, H312, H332from source

Keep roaming

Where Cyclobenzaprine leads

Sources & methodology

PubChem CID
2895
Wikidata
Q5198674
Structure
PubChem → RDKit
LD50
PubChem
Similar molecules
MoleculeFinder fingerprint similarity
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