Cefalexin
Also called CEX, Ceporexin, Cepastar and Cepexin.
A first-generation cephalosporin antibiotic sold as Keflex, used for skin, bone, ear and urinary infections.
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.
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 carbon carrying both a C=O and an O-H, written COOH. In water it gives up that hydrogen, which is what makes the molecule an acid.
From: standard chemistry.
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.
A nitrogen carrying one or two hydrogens. Its spare pair of electrons can pick up a hydrogen ion, so an 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.
Properties and sources
Calculated by PubChem
- Molecular formula
- C16H17N3O4S
- Molecular weight
- 347.4 g/mol
- XLogP3octanol/water, log units
- 0.6
- Polar surface areatopological
- 138 Ų
- H-bond donors
- 3
- H-bond acceptors
- 6
- Rotatable bonds
- 4
- Complexity
- 600
Reported Hazard label (GHS), ECHA via PubChem
Danger Irritant pictogram (GHS07) and Health hazard pictogram (GHS08); hazard statements H317, H334
Reported Licence
The US Food and Drug Administration licenses Cefalexin for human use (ANDA 062702, authorized February 13, 1987). Drugs@FDA
Groups it belongs to
- Category
- Prescription medicine
- Family
- Antibiotics
- Chemical groups
- Carboxylic Acids, Amines, Aromatics, Amides
- Hazard classes
- Irritant, Health hazard, GHS Danger
CC1=C(N2[C@@H]([C@@H](C2=O)NC(=O)[C@@H](C3=CC=CC=C3)N)SC1)C(=O)OPubChem CID 27447 · Wikidata Q411417 · InChIKey ZAIPMKNFIOOWCQ-UEKVPHQBSA-N · Data refreshed
Questions
- What is Cefalexin?
- A first-generation cephalosporin antibiotic sold as Keflex, used for skin, bone, ear and urinary infections.
- How toxic is Cefalexin?
- Its GHS hazard label carries the signal word Danger and the hazard pictograms Irritant and Health hazard. from source
- What kind of molecule is Cefalexin?
- Cefalexin has the formula C16H17N3O4S and a molecular weight of 347.4 g/mol. MoleculeFinder files it under antibiotics, in the prescription medicine group. from sourcefrom sourcefrom sourcefrom source
- What else is Cefalexin called?
- Cefalexin is also called CEX, Ceporexin, Cepastar and Cepexin. from source
- Who licenses Cefalexin as a medicine?
- The US Food and Drug Administration licenses Cefalexin for human use (ANDA 062702, authorized February 13, 1987). 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
Sources and notes
- 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