moleculefinder

Allopurinol

C5H4N4O136.11 g/mol Calculated

A medicine that lowers uric acid, used to prevent gout attacks and kidney stones. Allopurinol (C5H4N4O, 136 g/mol) is a compound dispensed on prescription.

Sources and notes
  • The introductionfrom sourceMoleculeFinder curated
  • 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. Allopurinol on the product labels we hold.

Medicines

ZyloprimAdded 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.

Rings joined where they share atoms, or a single ring standing alone. Atoms in a ring are held in place, so this part keeps its shape while chains around it can bend.

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.

Properties and sources

Calculated by PubChem

Molecular formula
C5H4N4O
Molecular weight
136.11 g/mol
XLogP3octanol/water, log units
−0.5
Polar surface areatopological
65.9 Ų
H-bond donors
2
H-bond acceptors
2
Rotatable bonds
0
Complexity
275

Reported Licence

The US Food and Drug Administration licenses Allopurinol for human use (NDA 016084, authorized August 19, 1966). Drugs@FDA

Groups it belongs to

Category
Prescription medicine
Elements
Nitrogen
SMILESC1=C2C(=NC=NC2=O)NN1

PubChem CID 2094 · Wikidata Q412486 · InChIKey OFCNXPDARWKPPY-UHFFFAOYSA-N · Data refreshed

How MoleculeFinder sources and labels its data

Questions
What is Allopurinol?
A medicine that lowers uric acid, used to prevent gout attacks and kidney stones. Allopurinol (C5H4N4O, 136 g/mol) is a compound dispensed on prescription.
What kind of molecule is Allopurinol?
Allopurinol has the formula C5H4N4O and a molecular weight of 136.11 g/mol. MoleculeFinder files it in the prescription medicine group. from sourcefrom sourcefrom source
Who licenses Allopurinol as a medicine?
The US Food and Drug Administration licenses Allopurinol for human use (NDA 016084, authorized August 19, 1966). from source
Sources and notes
  • Calculated valuescomputedPubChemComputed from the structure, so no laboratory conditions apply; complexity is PubChem's own structural score.
  • Licencefrom sourceDrugs@FDARead 2026-10-21.
  • Data refreshedfrom sourceMoleculeFinder2026-11-09