moleculefinder

Lorazepam

C15H10Cl2N2O2321.2 g/mol Calculated

Also called Ativan, O-Chlorooxazepam and O-Chloroxazepam.

The benzodiazepine sold as Ativan, used for anxiety, seizures and sedation before procedures. Lorazepam (C15H10Cl2N2O2, 321 g/mol) is a benzodiazepine dispensed on prescription.

Sources and notes
  • The introductionfrom sourceMoleculeFinder curated
  • Other namesfrom sourceWikidataIts English label and aliases on 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. Lorazepam on the product labels we hold.

Medicines

AtivanAdded by the makerActive ingredient

Every product and list we hold

Sources and notes
  • The product labels and their strengthsfrom sourceDailyMed (FDA label)Each label lists the molecule as an ingredient, and an active ingredient at the strength shown.
  • How it gets therefrom sourceMoleculeFinder curatedEach mark is set by hand on our lists, never inferred; a label's ingredient is added by the maker. A row with no mark data says Not marked.
  • The line abovefrom sourceMoleculeFinder curatedFrom the group the molecule belongs to.

Explore its structure

Choose a part to light it up.

A C=O bonded to a nitrogen, the same link that joins amino acids in a protein. It is sturdy, and its nitrogen is not a base the way an amine's is.

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

Diazepam

Lorazepam

Three differences: a methyl group on diazepam, and a hydroxyl group and a chlorine on lorazepam.

Diazepam breaks down into several active metabolites that build up with repeated use, while lorazepam produces none, so its effect ends more cleanly.

Diazepam vs Lorazepam, 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
C15H10Cl2N2O2
Molecular weight
321.2 g/mol
XLogP3octanol/water, log units
2.4
Polar surface areatopological
61.7 Ų
H-bond donors
2
H-bond acceptors
3
Rotatable bonds
1
Complexity
443

Reported Hazard label (GHS), ECHA via PubChem

Warning Health hazard pictogram (GHS08); hazard statements H361

Reported Licence

The US Food and Drug Administration licenses Lorazepam for human use (NDA 017794, authorized September 30, 1977). Drugs@FDA

Groups it belongs to

Category
Prescription medicine
Family
Benzodiazepines
Chemical groups
Alcohols, Aromatics, Amides, Halogenated
Elements
Chlorine, Nitrogen
Hazard classes
Health hazard, GHS Warning
SMILESC1=CC=C(C(=C1)C2=NC(C(=O)NC3=C2C=C(C=C3)Cl)O)Cl

PubChem CID 3958 · Wikidata Q408265 · InChIKey DIWRORZWFLOCLC-UHFFFAOYSA-N · Data refreshed

How MoleculeFinder sources and labels its data

Questions
What is Lorazepam?
The benzodiazepine sold as Ativan, used for anxiety, seizures and sedation before procedures. Lorazepam (C15H10Cl2N2O2, 321 g/mol) is a benzodiazepine dispensed on prescription.
How toxic is Lorazepam?
Its GHS hazard label carries the signal word Warning and the hazard pictogram Health hazard. from source
What kind of molecule is Lorazepam?
Lorazepam has the formula C15H10Cl2N2O2 and a molecular weight of 321.2 g/mol. MoleculeFinder files it under benzodiazepines, in the prescription medicine group. from sourcefrom sourcefrom sourcefrom source
What else is Lorazepam called?
Lorazepam is also called Ativan, O-Chlorooxazepam and O-Chloroxazepam. from source
Who licenses Lorazepam as a medicine?
The US Food and Drug Administration licenses Lorazepam for human use (NDA 017794, authorized September 30, 1977). from source
Sources and notes
  • Calculated valuescomputedPubChemComputed from the structure, so no laboratory conditions apply; complexity is PubChem's own structural score.
  • Hazard labelfrom sourceECHA 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

Three differences: a methyl group on diazepam, and a hydroxyl group and a chlorine on lorazepam.DiazepamC16H13ClN2OAlso a benzodiazepineOxazepamC15H11ClN2O2Also a benzodiazepineTemazepamC16H13ClN2O2Also a benzodiazepineClonazepamC15H10ClN3O3
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.
  • The drawingscomputedPubChem structures, drawn by RDKit