Chemistry and drugs · Database
ChEMBL
A curated database of bioactive molecules and protein targets for drug discovery and chemogenomics research.
What ChEMBL is
ChEMBL is a manually curated resource that brings together chemical, bioactivity, and genomic data. It holds information on drug-like molecules and their activity against biological targets, supporting the translation of genomic data into effective therapeutics. The database contains over 2.4 million compounds.
The database originated as StARlite at the biotechnology company Inpharmatica Ltd. (subsequently acquired by Galapagos NV) before being acquired for the European Molecular Biology Laboratory (EMBL) in 2008 through Wellcome Trust funding. Today, it is maintained by the Chemical Biology Resources team at the European Bioinformatics Institute (EMBL-EBI) in Hinxton, United Kingdom, and serves as an ELIXIR Core Data Resource and Global Core Biodata Resource.
How it is organised
ChEMBL extracts and standardises bioactivity data manually from peer-reviewed medicinal chemistry literature across multiple journals, as well as integrating confirmatory assays from external repositories such as PubChem. Reported quantitative bioactivity metrics include inhibition constants (Ki), dissociation constants (Kd), half-maximal inhibitory concentrations (IC50), and half-maximal effective concentrations (EC50).
To facilitate comparative analysis and computational data mining, the database normalises activity measurements across differing publications and assay formats. Researchers can query the database via a web interface, programmatic web services, or complete downloads via File Transfer Protocol (FTP).
Key facts
- Maintainer
- European Bioinformatics Institute (EMBL-EBI)
- Initial developer
- Inpharmatica Ltd.
- Total compounds
- 2.4 million
- Bioactivity metrics
- Ki, Kd, IC50, EC50
- Access methods
- Web interface, REST web services, FTP download
- Associated resources
- UniChem, SureChEMBL, ChEMBL-NTD, Kinase SARfari, GPCR SARfari, ADME SARfari
What you can use it for
- Lead identification and screening library design
- Filtering and analysing quantified bioactivity measurements to select candidate molecules and construct focused compound screening sets.
- Target-focused chemogenomics
- Investigating family-specific pharmacology and cross-species target profiles using specialised workbenches such as Kinase SARfari, GPCR SARfari, and ADME SARfari.
- Neglected tropical disease research
- Accessing and contributing open-access primary screening and medicinal chemistry datasets through the dedicated ChEMBL-NTD portal and malaria data services.
Query it here
The research agent queries ChEMBL directly — no account, no API key — and every answer links back to the record it came from. Ask in plain language and it writes the query.
Strengths and limits
Good at
- Standardises bioactivity endpoints across thousands of literature sources to enable computerised comparative analysis.
- Directly integrates chemical structures with quantitative bioactivity metrics and curated genomic target data.
- Maintains cross-references across broader chemical databases via UniChem and integrations with PubChem and ChemSpider.
Watch out for
- Bioactivity data extraction requires manual curation from literature, creating inherent dependencies on publication coverage.
- Focuses primarily on drug-like compounds and curated targets rather than entire synthetic chemical spaces.
Questions
Can I search ChEMBL without writing code?
Yes. The research agent queries ChEMBL directly, with no account or API key, and cites the record behind every answer. Ask in plain language — for a gene, a protein, a compound or a study — and it builds the query for you.
Can I reuse data from ChEMBL?
CC BY-SA 3.0. Share-alike: a derived database redistributed onward carries the same licence. Terms: https://chembl.gitbook.io/chembl-interface-documentation/about
Which quantitative bioactivity metrics are recorded in ChEMBL?
ChEMBL extracts and standardises binding affinity and potency endpoints, specifically Ki, Kd, IC50, and EC50 values.
How can researchers access ChEMBL data?
Data can be searched via the online web portal, accessed programmatically using ChEMBL web services, or downloaded in bulk via FTP.
What is ChEMBL-NTD?
ChEMBL-NTD is an associated open-access repository for primary screening and medicinal chemistry data targeting neglected tropical diseases.
How to cite it
Barbara Zdrazil, Eloy Felix, Fiona Hunter, Emma J Manners, James Blackshaw, Sybilla Corbett, Marleen de Veij, Harris Ioannidis, David Mendez Lopez, Juan F Mosquera, Maria Paula Magarinos, Nicolas Bosc, Ricardo Arcila, Tevik Kizilören, Anna Gaulton, A Patrícia Bento, Melissa. F Adasme, Pater Monecke, Gregory A Landrum, Andrew R Leach - Nucleic Acids Res. 2023: gkad1004. doi: 10.1093/nar/gkad1004
Written from ChEMBL's own website and reference material. Statements citing a figure that does not appear there are removed before publication. Licence and running details come from our registry.