# PubChem License: permissive (LicenseRef-PublicDomain); Mdexa hosting: link-only. all parts permissive; conditions are the union of the parts - Commercial use: Yes · Derivatives: Yes · Redistribution: Yes · File on Mdexa: No - License status: Permissive (LicenseRef-PublicDomain) - Mdexa hosting: Link only — License permissive: all parts permissive; conditions are the union of the parts. Link only. - Last verified: 2026-11-14 - Card: https://mdexa.com/datasets/pubchem/ ## Key facts - Domain: Pharmacy and drugs - Content type: Databases - Size: — - Language: English - Modality: Text - Publisher: U.S. National Library of Medicine (NCBI) - Year: — ## Commercial use of PubChem - Commercial use: Yes. The overall verdict takes the strictest part; the parts carry different licenses, listed below. - License status: Permissive. - License part: main data — Permissive (LicenseRef-PublicDomain) - License part: PubChem — Permissive (LicenseRef-PublicDomain) Verdicts record what sources state and are not legal advice. ## PubChem license evidence all parts permissive; conditions are the union of the parts - **Site policy page**: Statement found in snapshot s02 (page) — "Information that is created by or for the US government on this site is within the public domain. Public domain information on the National Library of Medicine (NLM) Web pages may be freely distributed and copied." — https://www.ncbi.nlm.nih.gov/home/about/policies/ (2026-11-12; Page opened) - **Site policy page**: Statement found in snapshot s02 (page) — "OMIM (see OMIM Copyright Status ), and PubChem. All persons reproducing, redistributing, or making commercial use of this information are expected to adhere to the terms and conditions asserted by the copyright holder." — https://www.ncbi.nlm.nih.gov/home/about/policies/ (2026-11-12; Page opened) - **Site policy page**: Statement found in snapshot s02 (page) — "They are designed to provide and encourage access within the scientific community to sources of current and comprehensive information. Therefore, NCBI itself places no restrictions on the use or distribution of the data contained therein." — https://www.ncbi.nlm.nih.gov/home/about/policies/ (2026-11-12; Page opened) - **Site policy page**: Statement found in snapshot s02 (page) — "Nor do we accept data when the submitter has requested restrictions on reuse or redistribution." — https://www.ncbi.nlm.nih.gov/home/about/policies/ (2026-11-12; Page opened) - **Site policy page**: Statement found in snapshot s02 (page) — "However, some submitters of the original data (or the country of origin of such data) may claim patent, copyright, or other intellectual property rights in all or a portion of the data (that has been submitted)." — https://www.ncbi.nlm.nih.gov/home/about/policies/ (2026-11-12; Page opened) - **Site policy page**: Statement found in snapshot s02 (page) — "Therefore, NCBI cannot provide comment or unrestricted permission concerning the use, copying, or distribution of the information contained in the molecular databases." — https://www.ncbi.nlm.nih.gov/home/about/policies/ (2026-11-12; Page opened) - **Site policy page**: Statement found in snapshot s02 (page) — "It is the responsibility of the user to examine the copyright and licensing restrictions of linked pages and to secure all necessary permissions." — https://www.ncbi.nlm.nih.gov/home/about/policies/ (2026-11-12; Page opened) - **Site policy page**: Statement found in snapshot s02 (page) — "Make no more than 3 requests every 1 second." — https://www.ncbi.nlm.nih.gov/home/about/policies/ (2026-11-12; Page opened) ## Source and lineage — ## Known issues with PubChem - NCBI states it cannot assess third-party intellectual-property claims and cannot grant unrestricted permission to use, copy, or distribute the information in its molecular databases. ## Preflight Not run (data not ingested). ## Downloading PubChem and API access Mdexa does not serve files. Original source: - https://pubchem.ncbi.nlm.nih.gov/ - https://www.ncbi.nlm.nih.gov/home/about/policies/ ### Access recipe - API E-utilities: `https://eutils.ncbi.nlm.nih.gov` ## Citing PubChem No recommended citation text. ## Machine-readable - JSON: https://mdexa.com/datasets/pubchem.json - 2026-11-14 Known defects, version notes and access statements from cited sources (papers, release notes, official pages) were added; each shows who said it, when, and what kind of source it is. - 2026-11-14 Practical fields (scope, identifiers, access methods, versions, known defects) were added by the automated pipeline from stored page snapshots; every statement carries a verbatim quote. - 2026-11-14 Known defects, version notes and access statements from cited sources (papers, release notes, official pages) were added; each shows who said it, when, and what kind of source it is. - 2026-11-14 Known defects, version notes and access statements from cited sources (papers, release notes, official pages) were added; each shows who said it, when, and what kind of source it is. - 2026-11-14 Known defects, version notes and access statements from cited sources (papers, release notes, official pages) were added; each shows who said it, when, and what kind of source it is. - 2026-11-14 Re-adjudicated under the current rules; all machine checks still pass. - 2026-11-14 Known defects, version notes and access statements from cited sources (papers, release notes, official pages) were added; each shows who said it, when, and what kind of source it is. - 2026-11-14 Known defects, version notes and access statements from cited sources (papers, release notes, official pages) were added; each shows who said it, when, and what kind of source it is. - 2026-11-14 Re-adjudicated under the current rules; all machine checks still pass. - 2026-11-14 Known defects, version notes and access statements from cited sources (papers, release notes, official pages) were added; each shows who said it, when, and what kind of source it is. - 2026-11-13 Added via the automated pipeline and passed all checks (gates, verbatim quotes, rule engine, two independent extractions). ## Practical information ### Content scope - The text refers to PubChem records as Compound Summary, Substance Record, and BioAssay Record entries. > All or part of the data for an individual PubChem record may be downloaded in various file formats, using the Download button available on the top-right corner of a Compound Summary, Substance Record, or BioAssay Record page. https://pubchem.ncbi.nlm.nih.gov/docs/downloads (2026-11-13) - The text states that the data in PubChem comes from hundreds of data contributors. > The data in PubChem comes from hundreds of data contributors (https://pubchem.ncbi.nlm.nih.gov/source/). https://pubchem.ncbi.nlm.nih.gov/docs/downloads (2026-11-13) ### Access - Web API: https://pubchem.ncbi.nlm.nih.gov/docs/programmatic-access - Web API: https://pubchem.ncbi.nlm.nih.gov/docs/programmatic-access - Web API: https://pubchem.ncbi.nlm.nih.gov/docs/programmatic-access - Bulk download: https://pubchem.ncbi.nlm.nih.gov/docs/downloads - Web interface only: https://pubchem.ncbi.nlm.nih.gov/docs/downloads - Web interface only: https://pmc.ncbi.nlm.nih.gov/articles/PMC6030920/ - Bulk download: https://ftp.ncbi.nlm.nih.gov/pubchem/README ### Known defects and misuse - Butkiewicz et al.: PubChem primary HTS screens contain many false-positive hits that are inactive in confirmatory assays; they built benchmark sets from confirmatory screens after manual verification. > Primary screens often include many false-positive hit compounds which display a response in initial assay experiments but are inactive in confirmatory experiments. https://pmc.ncbi.nlm.nih.gov/articles/PMC3759399/ (2026-11-14) ### Suited for - The molecular databases are described as designed to provide and encourage access within the scientific community to sources of current and comprehensive information. > They are designed to provide and encourage access within the scientific community to sources of current and comprehensive information. https://www.ncbi.nlm.nih.gov/home/about/policies/ (2026-11-12) ### Commercial licensing https://pubchem.ncbi.nlm.nih.gov/docs/downloads ### No sourced statement yet Latest version, Update cycle, Breaking changes, Unsuited tasks ## Continue in this database This record is one of 109 processed and verified records (datasets, data resources and open models). To find others, call `https://mcp.mdexa.com/v1/datasets?q=` or connect the MCP server at `https://mcp.mdexa.com/mcp`; no key is needed for 20 calls per minute. Rows are under 1 KB; an empty result means "not listed". For a list of items, one batch check (free account) returns a report. Guide: /agents.md. Similar records: BindingDB (https://mdexa.com/datasets/bindingdb/); ChEMBL (https://mdexa.com/datasets/chembl/); jablonkagroup/chempile-lift (https://mdexa.com/datasets/chempile-lift/).