Reference · RxNorm

RxNorm Concept Directory

RxNorm: 226,378 normalized drug concepts from ingredients and brand names through clinical drugs, dose forms, and packs. Cross-mapped to UMLS, SNOMED CT, and NDC.

Featured ingredients

1801150(((1-methyl-2-(5-methyl-3-oxazolidinyl)ethoxy)methoxy)methoxy)methanolIN 1599828((2s,3s,5s)-2-(2-(2,6-dimethylphenoxy)acetamido)-5-((s)-3-methyl-2-(2-oxotetrahydropyrimidin-1(2h)-yl)butanamido)-1,6-diphenylhexan-3-yl) 3-methyl-2-(2-oxotetrahydropyrimidin-1(2h)-yl)butanoate, (s)-IN 2599921((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)IN 2557381(-)-ambroxideIN 2262004(1,1-dimethylethyl)ureaIN 1989005(1,2,6,7-3H)-testosteroneIN 2058838(1-cyanocyclohexyl)acetic acidIN 2380376(2-(((2-(2-amino-3-hydroxy-2-(hydroxymethyl)propoxy)-1-hydroxypropyl)hydroxyphosphoryl)oxy)-1-hydroxypropyl)phosphonateIN 2634407(2-amino-5,6-dichloroquinazolin-3(4h )-yl)acetic acidIN 1314258(2-carbethoxyethyl)diethoxy(methyl)silaneIN 2475947(2-carbethoxyethyl)triethoxysilaneIN 2104168(2-chlorophenyl)methyl 4-hydroxybenzoateIN 2375705(2-hydroxyethyl)(hydroxymethyl)amineIN 2685740(2-naphthyloxy)acetic acidIN 2557900(2S)-3-phenylpropane-1,2-diolIN 2371035(3-aminopropyl)diethanolamineIN 2391134(3-bromopropyl)benzeneIN 2368125(3-chloropropyl)trimethoxysilaneIN 2557369(3Z)-hex-3-en-1-yl methyl carbonateIN 2169961(4-(trifluoromethoxy)phenyl)ureaIN 1995480(9Z)-9-octadecenyl acetateIN 1312357(C10-C30)alkyl methacrylate esterIN 2643432(N-(3-cholamidopropyl)-N-(3-lactobionamidopropyl))cholamideIN 1360626(all-Z)-4,7,10,13,16-docosapentaenoic acidIN

Browse by term type

SCDClinical drug

35,388

SCDCClinical drug component

28,078

SBDBranded drug

20,704

SBDGBranded drug form group

19,989

SBDCBranded drug component

19,206

SCDGClinical drug form group

16,318

SCDFClinical drug form

15,006

SBDFBranded drug form

SBDFPBranded drug pack

5,098

SCDGPClinical drug group pack

4,753

SYSynonym

4,449

SCDFPClinical drug pack

4,439

PSNPrescribable name

4,243

MINMultiple ingredient

3,812

PINPrecise ingredient

577

193

184

# same data, as API
GET /v1/reference/rxnorm/{rxcui}
GET /v1/reference/rxnorm/search?q=metformin

RxNorm, plainly answered

What is RxNorm?

RxNorm is the NLM's normalized naming system for clinical drugs and dose forms. It collapses brand variants, packaging differences, and source-vocabulary noise into a single, stable identifier (RxCUI) per concept, with explicit links to ingredients, brands, and clinical drug forms.

What are RxCUIs?

An RxCUI is the persistent ID for a single RxNorm concept. The same RxCUI keeps pointing at the same drug concept release after release, even when names or sources change. That stability is what makes RxNorm useful for medication reconciliation and analytics.

How does RxNorm relate to NDC codes?

NDC codes describe a specific package SKU at a specific manufacturer. RxNorm describes the clinically relevant drug. One RxCUI can map to dozens of NDCs (different manufacturers, different package sizes), and we list those NDC mappings on each concept page.

How does RxNorm cross-map to other standards?

RxNorm concepts carry direct links to UMLS CUIs and SNOMED CT product codes when available. Through the UMLS bridge they can also reach ICD-10 codes (for instance, for indication-based coding) and LOINC observations. Our API exposes all of this on the cross_references field.

Is the API free to use?

Browsing concepts is free. Programmatic access at /v1/reference/rxnorm/* requires an API key. RxNorm itself is in the public domain, so there is no upstream license fee, but our bandwidth and uptime are not.

How fresh is the RxNorm data?

RxNorm releases monthly. We rebuild within a few business days of each release, and the concept-id history is preserved so previous lookups continue to resolve.