moleculefinder

Amitriptyline

C20H23N277.4 g/mol Calculated

Also called Adepril, Damilen, Flavyl and Lantron.

A tricyclic antidepressant now prescribed far more often at low strength for nerve pain, migraine prevention and sleep than for depression.

Sources and notes
  • The introductionfrom sourceMoleculeFinder curated
  • Other namesfrom sourcePubChem / Wikidata
  • Formula and weightcomputedPubChem
  • 2D drawingcomputedPubChem structure, drawn by RDKit
  • 3D modelfrom sourcePubChem 3D conformerLoaded after the page has painted, and on a phone only when you ask for it; the 2D drawing shows until it arrives.

Where you encounter it

Dispensed on prescription, not sold on a shelf.

Sources and notes
  • The line abovefrom sourceMoleculeFinder curatedFrom the group the molecule belongs to.

Explore its structure

Choose a part to light it up.

A nitrogen bonded to three carbons, with no hydrogen of its own. Its spare pair of electrons can still pick up a hydrogen ion, so a tertiary amine is a base.

From: standard chemistry.

Sources and notes
  • The drawingcomputedPubChem structure, drawn by RDKitThe page's one shipped drawing, with the chosen part lit in amber under it.
  • The partscomputedFound by ruleEach part is found by a chemical pattern, never picked by hand atom by atom; its words say where they come from.

Compare a related molecule

Amitriptyline

Nortriptyline

One methyl group apart.

Nortriptyline is amitriptyline minus one methyl group, made from it by the body, and it is the less sedating of the two tricyclics.

Amitriptyline vs Nortriptyline, side by side
Sources and notes
  • The sentencefrom sourceMoleculeFinder comparison notesThe pair's answer line.
  • The two drawingscomputedPubChem structures, drawn by RDKitDrawn the same way round; the amber marks where the two differ.
  • The captionfrom sourceMoleculeFinder curated

Properties and sources

Calculated by PubChem

Molecular formula
C20H23N
Molecular weight
277.4 g/mol
XLogP3octanol/water, log units
5
Polar surface areatopological
3.2 Ų
H-bond donors
0
H-bond acceptors
1
Rotatable bonds
3
Complexity
331

Measured LD50, HSDB via PubChem

140 mg/kg pure amitriptyline, mouse, oral

An LD50 is an animal study measurement, not a dose for a person.

Reported Hazard label (GHS), ECHA, HSDB via PubChem

Danger Corrosive pictogram (GHS05), Toxic pictogram (GHS06), Irritant pictogram (GHS07), Health hazard pictogram (GHS08) and Environmental pictogram (GHS09); hazard statements H301, H302, H311, H318, H331, H361, H410

Reported Licence

The US Food and Drug Administration licenses Amitriptyline for human use (ANDA 085970, authorized November 21, 1977). Drugs@FDA

Groups it belongs to

Category
Prescription medicine
Family
Tricyclic antidepressants
Chemical groups
Aromatics
Elements
Nitrogen
Hazard classes
Corrosive, Acutely toxic, Irritant, Health hazard, Environmental hazard, GHS Danger
SMILESCN(C)CCC=C1C2=CC=CC=C2CCC3=CC=CC=C31

PubChem CID 2160 · Wikidata Q58397 · InChIKey KRMDCWKBEZIMAB-UHFFFAOYSA-N · Data refreshed

How MoleculeFinder sources and labels its data

Questions
What is Amitriptyline?
A tricyclic antidepressant now prescribed far more often at low strength for nerve pain, migraine prevention and sleep than for depression.
How toxic is Amitriptyline?
The reported LD50 of Amitriptyline is 140 mg/kg (mouse, oral). An LD50 is an animal study measurement, not a dose for a person. Its GHS hazard label carries the signal word Danger and the hazard pictograms Corrosive, Toxic, Irritant, Health hazard and Environmental. from sourcefrom source
What kind of molecule is Amitriptyline?
Amitriptyline has the formula C20H23N and a molecular weight of 277.4 g/mol. MoleculeFinder files it under tricyclic antidepressants, in the prescription medicine group. from sourcefrom sourcefrom sourcefrom source
Who licenses Amitriptyline as a medicine?
The US Food and Drug Administration licenses Amitriptyline for human use (ANDA 085970, authorized November 21, 1977). from source
Sources and notes
  • Calculated valuescomputedPubChemComputed from the structure, so no laboratory conditions apply; complexity is PubChem's own structural score.
  • LD50from sourceHSDB via PubChemOther values the sources report: mouse, intravenous, 16 mg/kg; mouse, another route, 56 mg/kg; mouse, another route, 140 mg/kg. The page shows the one LD50 the site uses everywhere.
  • Hazard labelfrom sourceECHA, HSDB via PubChemThe label combines these classifications.
  • ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
  • Licencefrom sourceDrugs@FDARead 2026-10-21.
  • Data refreshedfrom sourceMoleculeFinder2026-11-09

Keep exploring

One methyl group apart.NortriptylineC19H21NAlso a tricyclic antidepressantDoxepinC19H21NOAlso a tricyclic antidepressantImipramineC19H24N2Both carry an aromatic ring.CyclobenzaprineC20H21N
Sources and notes
  • A group apartfrom sourceMoleculeFinder comparison captions
  • The same kind of moleculefrom sourceMoleculeFinder curated groupsA structural neighbour in the same family or type group; the line names the group in its own words.
  • Similar in shapecomputedRDKit Morgan/TanimotoNeighbours by structural fingerprint; the sentence names the chemical groups the two share.
  • The drawingscomputedPubChem structures, drawn by RDKit