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Fact Sheet

MEDLINE® (Medical Literature, Analysis, and Retrieval System Online) is the U.S. National Library of Medicine's (NLM) premier bibliographic database that contains over 12 million references to journal articles in life sciences with a concentration on biomedicine. It can be searched via PubMed® or the NLM Gateway.

Time coverage: 1966 to the present.

Source: Citations from over 4,600 worldwide journals currently in 30 languages; 40 languages for older journals cited back to 1966. About 52% of current cited articles are published in the U.S.; for the time period 1997-2001, nearly 89% of cited articles are published in English and about 76% have English abstracts written by authors of the articles. Citations for MEDLINE are created by the NLM, international partners, and collaborating organizations.

Updates: Beginning in 2002 over 2,000 completed references are added daily each Tuesday through Saturday, January through October (over 460,000 added last year). Updates are irregular in November and December as NLM makes the transition to a new year of Medical Subject Headings (MeSH®) vocabulary used to index the articles.

Broad coverage: Basic biomedical research and the clinical sciences since 1966 including nursing, dentistry, veterinary medicine, pharmacy, allied health, and pre-clinical sciences. MEDLINE also covers life sciences that are vital to biomedical practitioners, researchers, and educators, including some aspects of biology, environmental science, marine biology, plant and animal science as well as biophysics and chemistry. Increased coverage of life sciences began in 2000. By the end of 2001, most citations previously included in separate NLM specialty databases had also been added to MEDLINE.

Availability: MEDLINE, the primary subset of PubMed, is available on the Internet through the NLM home page at and can be searched free of charge. No registration is required. MEDLINE services are also provided by organizations that lease the database from NLM. Access to various MEDLINE services is often available from medical libraries, many public libraries, and commercial sources.

The MEDLINE/PubMed link from the Welcome statement on NLM's home page takes you to the web-based service, PubMed® which allows you to begin your MEDLINE search. MEDLINE can be searched using NLM's controlled vocabulary MeSH, or by author name, title word, text word, journal name, phrase, or any combination of these. The result of a search is a list of citations (including authors, title, source, and often an abstract) to journal articles. PubMed also searches MEDLINE in-process citations that are added daily, as well as some citations that come electronically directly from publishers. MEDLINE's in-process and the publisher-supplied citations are not indexed with MeSH. MEDLINE/PubMed may also be searched using the NLM Gateway, a single Web interface that searches multiple NLM retrieval systems. The Gateway also includes a search of OLDMEDLINE, which contains journal citations published largely before 1966.

The "Loansome Doc®" feature in PubMed lets you easily and quickly place an electronic order through the National Network of Libraries of Medicine® (NN/LM) for the full-text copy of an article found in MEDLINE. Registration is required and local fees may apply for this service. For over 3,000 journals, and the number continues to increase, you can also link from a MEDLINE reference to the publisher's web site to request or view the full article. User registration, a subscription fee, or some other type of fee may be required by the publisher to access the full-text of articles in some journals.

MedlinePlus®, another service offered by the NLM, provides consumer-oriented health information. Health consumers are encouraged to discuss search results with their health care provider.

For further information about MEDLINE send e-mail to or contact NLM toll-free at 1-888-346-3656. For the nearest local medical library in your area contact the NN/LM at 1-800-338-7657.

Related NLM Fact Sheets on the web at are:

Sample Record: PubMed MEDLINE Citation display format

Sample PubMed record in Citation display format

Sample Record: PubMed MEDLINE display format

Sample PubMed record in MEDLINE display format

First published: 18 September 2002
Last updated: 18 September 2002
Date Archived: 01 December 2004
Metadata | Permanence level: Permanent: Stable Content
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Last updated: 18 September 2002
First published: 18 September 2002
Metadata| Permanence level: Permanent: Stable Content