What is PubMed?
Most researchers in the health and life sciences are familiar with PubMed, a free database maintained by the National Library of Medicine, part of the National Institutes of Health. It currently contains over 37 million citations and is made up of three components. The largest is MEDLINE, a dataset of references from journals that have been specifically selected for indexing. The second component is PubMed Central, or PMC, a free full text journal archive that also includes manuscripts and preprints related to research funded by the National Institutes of Health; some PMC journals are indexed in MEDLINE, but not all. Finally, there is the Bookshelf, which includes the full text of books and reports published by the U.S. federal government and other organizations.
So MEDLINE and PubMed aren’t the same?
No, although people often use the names interchangeably. MEDLINE is searchable freely via PubMed, but there are also database publishers that provide an alternate interface to the MEDLINE database. Those interfaces frequently offer much more sophisticated searching options, which can be valuable for finding information on complex topics and for comprehensive searching for evidence synthesis projects. Of these subscription options, we recommend Ovid MEDLINE.
Why would I search Ovid MEDLINE and not PubMed?
This may be a matter of personal preference. If you’re looking for powerful and flexible search options, you might choose Ovid MEDLINE. Or you might prefer PubMed’s straightforward interface and its integrated access to PMC.
It could also be an access issue. Over the weekend of March 1-2 of 2025, the performance of PubMed’s servers became erratic, making the database only intermittently available. In short-term situations like this, members of the Brown University community who generally prefer PubMed may wish to use Ovid MEDLINE temporarily instead.
Are there any other ways to search MEDLINE besides PubMed and Ovid MEDLINE?
Yes! Two excellent options are freely available:
Europe PMC integrates content from a range of sources, which include PubMed (both MEDLINE and PMC), Agricola, and 34 life science preprint servers including biorxiv, Research Square, and Preprints.org. As a result, it’s larger than Ovid MEDLINE or even PubMed.
The Lens aggregates data from a wide range of sources including, but not limited to, PubMed, Crossref, OpenAlex, ORCID, Microsoft Academic and several patent offices. That makes it larger than both PubMed and Europe PMC.
So PubMed and MEDLINE are great. Why would I use other databases at all?
There are a number of things to consider when selecting a database.
While PubMed is especially valuable as a free resource worldwide, its core dataset, MEDLINE, is produced and maintained by the U.S. federal government. Since January 2025, many federal websites, datasets, and publications have been removed, withdrawn, or modified. There are growing concerns about the stability, reliability, and authority of the MEDLINE dataset, which were amplified by the recent temporary access problems. Medical librarians and other researchers worldwide are monitoring developments in order to be prepared for coverage or access changes.
However, these concerns are certainly not the only reason to use other clinical databases! Each database offers its own unique content, and using multiple databases is important to comprehensive research. Brown University subscribes to several excellent and important medical and interdisciplinary databases beyond PubMed/MEDLINE.
Ok, so which ones do you recommend?
Embase is an international biomedical and pharmacological database. There is some overlap with MEDLINE, but it indexes thousands of journals not covered by MEDLINE. Embase is particularly good for drug and medical device research and pharmacovigilance.
Web of Science is a multidisciplinary database including significant coverage of the scientific literature, including the health and life sciences. It also offers forward and backward citation searching.
Scopus is another database that searches across many disciplines. It has significant overlap with Embase and MEDLINE, as well as unique content. Forward and backward citation searching are available in Scopus.
Where can I easily bookmark all these options?
Visit our guide to Alternatives to PubMed to find all the resources above.
Brown also offers a custom link to PubMed where you’ll see our Brown “Find it!” buttons for access to our full text articles. To streamline your full text experience even more, in PubMed and on publisher websites, we recommend installing the free LibKey Nomad browser extension. Once you’ve added it to your browser, select Brown University as your organization.
Questions? Contact Your HBLS Librarians!
Email us at HealthSciLibrarians@brown.edu!
Image credit: https://www.nlm.nih.gov/oet/ed/pubmed/mesh/mod00/01-000.html