medRxiv (pronounced "med-archive") is an online disciplinary repository publishing preprints in all disciplines of the health sciences.

[1][2][3][4] It distributes papers in the areas of medicine and clinical research without charge to the reader.

[5] The site was founded in 2019 by John Inglis and Richard Sever of Cold Spring Harbor Laboratory (CSHL), Theodora Bloom and Claire Rawlinson of BMJ (the medical publisher), and Joseph Ross and Harlan Krumholz of Yale University.

medRxiv, and its sister site, bioRxiv, have been major sources for the dissemination of research on COVID-19.

In addition preprints reporting research funded by the National Institutes of Health are indexed by PubMed.