Preprints: A brief history and recommendations from the NIH for authors citing preprints

What is a preprint? 

Per Committee on Publication Ethics (COPE), a preprint is:  

  • A complete written description of scientific work that contains data and methods
  • Posted by an author to an openly accessible repository
  • Not yet submitted for peer review to a journal
  • Not formally published

Origin of preprints 

Preprints can be traced back to the Information Exchange Group (IEG) started by NIH in 1961. There were over 2,500 IEG memos disseminated via postal mail by 3,600 participants from 46 countries. The IEG was discontinued in 1967 after the release of an article published in Nature. The article discussed a series of decisions made by a group of journal publishers to not accept a manuscript that was previously released as an IEG memorandum and that IEG memoranda could not be cited in a published paper. To learn more, refer to The prehistory of biology preprints: A forgotten experiment from the 1960s.

NIH and preprints 

The NIH encourages investigators to use interim research products, such as preprints, to speed the dissemination and enhance the rigor of their work. 

NIH expects awardees to: 

  • Make the preprint publicly accessible
  • Follow recommended guidelines for selecting a preprint repository that abides by FAIR principles
  • Acknowledge NIH support/funding
  • Clearly state the work is not peer-reviewed
  • Declare any competing interests

NIH awardees are strongly encouraged to:  

NIH awardees can:  

  • Add citations for preprints in My Bibliography. (My Bibliography offers a template for adding preprints if a record for the preprint is not available from PubMed. See: Adding Citations Manually)
  • Associate awards to preprints in My Bibliography
  • *Claim preprints as products of their award on an RPPR
  • Cite preprints in a biosketch

*Note: Preprints are exempt from the NIH Public Access Policy as they are not peer-reviewed. 

PubMed Central

PubMed Central is continuing the preprint pilot and to date has over 3,000 preprint records in PubMed. As of 2021, there were 2,800 preprint records in PubMed and these were cited by more than 18,000 papers which in turn have been cited by approximately 130,000 papers. To learn more, see: A Captivating future:  The vital need for curation, access, preservation, and transparency in scientific communications. Presentation given by Kathryn Funk, Program Manager for PubMed Central, on November 17, 2021.  


  • Cobb M. The prehistory of biology preprints: A forgotten experiment from the 1960s. PLoS Biol. 2017 Nov 16;15(11):e2003995.
  • Dr. Michael Mullins from the Emergency Medicine Department recently authored an opinion piece on preprints: The Problem with Preprints. Per Dr. Mullins: “If the preprint becomes the end product (or a “no-print,” or no formal publication) for some authors, we risk being awash in a large quantity of publications of low quality.” Opinion: The Problem with Preprints. The Scientist, November 2021. 
  • Dr. Mitchell Scott from the Pathology and Immunology Department served as a moderator for a session about preprints held in 2017. Annesley T, Scott M, Bastian H, Fonseca V, Ioannidis JP, Keller MA, Polka J. Biomedical Journals and Preprint Services: Friends or Foes? Clin Chem. 2017 Feb;63(2):453-458.
  • Kodvanj I, Homolak J, Virag D, et al. Publishing of COVID-19 preprints in peer-reviewed journals, preprinting trends, public discussion and quality issues. Scientometrics. 2022.  
  • Brierley L, Nanni F, Polka JK, Dey G, Pálfy M, Fraser N, Coates JA. Tracking changes between preprint posting and journal publication during a pandemic. PLoS Biol. 2022 Feb 1;20(2):e3001285.  
  • Nicholson DN, Rubinetti V, Hu D, et al. Examining linguistic shifts between preprints and publications. PLoS Biol. 2022 Feb 1;20(2):e3001470.