Pharmaceuticals Data Provider: 22 Cataloged Datasets · Head-to-head
PubChem PUG REST API vs RxNorm / RxNav Browser and APIs
Which pharmaceuticals data provider: 22 cataloged datasets data fits your job: PubChem PUG REST API, or RxNorm / RxNav Browser and APIs. API, files, or your warehouse. Daily, weekly, or hourly.
PubChem PUG REST API
RxNorm / RxNav Browser and APIs
Where the fields line up
No shared field names. These two answer different questions.
| Field | PubChem PUG REST API | RxNorm / RxNav Browser and APIs |
|---|---|---|
CID | documented | not in this set |
MolecularFormula | documented | not in this set |
MolecularWeight | documented | not in this set |
SMILES | documented | not in this set |
ConnectivitySMILES | documented | not in this set |
InChIKey | documented | not in this set |
IUPACName | documented | not in this set |
XLogP | documented | not in this set |
TPSA | documented | not in this set |
HBondDonorCount | documented | not in this set |
HBondAcceptorCount | documented | not in this set |
RotatableBondCount | documented | not in this set |
Coverage, side by side
| PubChem PUG REST API | RxNorm / RxNav Browser and APIs | |
|---|---|---|
| Geographic | Global - chemistry drawn from worldwide depositors and literature; not geographically scoped | United States - the US-market drug vocabulary |
| Temporal | Continuous; daily incremental directories observed for each recent day in August 2026 | Monthly full release with weekly updates; live release identified as 03-Aug-2026 |
| Granularity | One record per compound (CID), substance (SID) or assay (AID) | One record per drug concept (RXCUI) across ingredient, branded drug, clinical drug and pack levels |
What each contains
They tie on 1 attribute. Pick by fit, not by loyalty.
| PubChem PUG REST API | RxNorm / RxNav Browser and APIs | |
|---|---|---|
| Publisher | NCBI PubChem (US National Library of Medicine) | NLM RxNav (Lister Hill National Center for Biomedical Communications) |
| Subject lens | Structural chemistry archive: compounds, substances, bioassays, genes, proteins, patents, taxonomy | Clinical drug vocabulary: normalized names, strengths, dose forms, NDC mappings and class hierarchies for the US market |
| Unit of analysis | One record per compound (CID), substance (SID) or assay (AID) | One record per drug concept (RXCUI) across ingredient, branded drug, clinical drug and pack levels |
| Scale | Tens of millions of compound records; full SDF dumps run ~280-320 MB per 500,000 compounds | ~120k+ concepts per monthly release, spanning SBD, SBP, IN, BPCK, GPCK and PSN term types |
| Geographic coverage | Global - chemistry drawn from worldwide depositors and literature; not geographically scoped | United States - the US-market drug vocabulary |
| Temporal cadence of releases | Continuous; daily incremental directories observed for each recent day in August 2026 | Monthly full release with weekly updates; live release identified as 03-Aug-2026 |
| Documented fields | 12 verified compound-property and structure fields | 12 verified concept, strength, dose-form and classification fields |
| Formats delivered | JSON, XML, CSV, TXT, SDF and PNG | JSON and XML |
| Rubric rating | 9 out of 10 (catalog average 7.81 across 1,744 datasets) | 9 out of 10 (catalog average 7.81 across 1,744 datasets) |
| Best for | Structure-first chemistry: properties, synonyms, substructure search, structure images | Prescription-reality vocabulary: normalize any drug string to a coded concept with strength and form |
Where they're equivalent
More than the molecule-versus-medicine split implies.
- Both are NLM-stewarded reference archives - government infrastructure behind each record, not a vendor's proprietary compilation.
- Both score 9 out of 10 on the rubric, tied at the top of the Pharmaceuticals slice against a 7.81 catalog-wide average.
- Both ship verified field dictionaries, every definition checked rather than inferred - a standard met by roughly 86 percent of the 1,744 cataloged datasets.
- Both update on a published rhythm - continuous daily incrementals on the chemistry side, monthly releases with weekly updates on the vocabulary side - so neither is a frozen snapshot.
- Neither covers the other's half: no strengths, brands or NDCs in PubChem; no structures, formulas or computed properties in RxNorm. Workflows wanting both halves use both records.
Fair questions
Do the two field dictionaries overlap?
Only where chemistry meets commerce: a name. PubChem keys everything on CID and documents twelve computed-and-structural fields per compound; RxNorm keys everything on RXCUI and documents fields like brandName, strength, rxtermsDoseForm, route and genericRxcui per drug concept. No field is shared, no key is shared - aspirin's CID 2244 and atorvastatin's RXCUI 262095 could never collide. The bridge is a lookup, not a join column.
Which record covers more of the world's molecules?
PubChem, by orders of magnitude. It aggregates deposited substances and standardized compounds from global chemistry - tens of millions of compounds, delivered in full SDF chunks of roughly 280-320 MB per 500,000 compounds. RxNorm deliberately scopes itself to the US market: about 120k+ concepts per monthly release covering clinical drugs, brands, packs and ingredients actually prescribed there. A compound that exists only as literature chemistry lives in PubChem; a capsule sold in American pharmacies lives in RxNorm.
Can one project use both records together?
Yes - as an identifier spine rather than a merged table. Resolve a drug string to its RXCUI on the RxNorm side, take the ingredient-level concept, then cross into PubChem through the ingredient name or CAS-style synonym to pull molecular properties for absorption, permeability or formulation models. The seam is real: naming conventions differ, salts and esters complicate the match, so resolve identifiers once and keep the two dictionaries separate downstream.
Can I get both records from Datadory?
Yes - sample both, pick by fit, or take both in one feed. Each arrives normalized to its documented field dictionary with sample rows attached for validation, delivered daily, weekly, or hourly - your call - alongside the rest of the pharmaceuticals catalog.