Unrestricted Access

Plugins required


PubMed, available via the National Center for Biotechnology Information (NCBI) Entrez life sciences retrieval system, was developed at the  National Library of Medicine (NLM), located at the U.S. National Institutues of Health (NIH). Entrez is the text-based search and retrieval system used at NCBI for services including PubMed, Nucleotide and Protein Sequences, Protein Structures, Complete Genomes, Taxonomy, OMIM, and many others. PubMed provides access to bibliographic information that includes MEDLINE and OLDMEDLINE.PubMed coverage also includes the following:

  • The out-of-scope citations (e.g., articles on plate tectonics or astrophysics) from certain MEDLINE journals, primarily general science and chemistry journals for which the life sciences articles are indexed for MEDLINE.
  • Citations that precede the date that a journal was selected for MEDLINE indexing.
  • Some additional life science journals that submit full text to PubMedCentral and receive a qualitative review by NLM


PubMed Tutorial page.

Adobe Acrobat Reader may be necessary when linking to some full-text articles.

For help using these indexes see: How do I find an article on my topic?

User tools and features

Alert Service.

Dates covered

MEDLINE contains over 17 million bibliographic citations and author abstracts from more than 5,000 biomedical journals dating back to the early 1950s.

Updating frequency



PubMed source journals may be found in a searchable database.

Type of coverage

PubMed contains bibliographic citations, indexing and abstracts with links to full-text journal articles of participating publishers. It also provides access and links to the integrated molecular biology databases included in NCBI's Entrez retrieval system.

Print counterpart or
related resources

The print counterparts of MEDLINE are Index Medicus, International Nursing Index and the Index to Dental Literature.

Producer/content provider

National Center for Biotechnology Information (NCBI)

Vendor/electronic presentation provider

National Center for Biotechnology Information (NCBI)