Definition
Evaluation of a research manuscript by independent experts before publication in a scholarly journal.
Peer review is the process by which journals send submitted manuscripts to independent experts who assess the methods, analysis and conclusions before publication. Reviewers may recommend acceptance, revision or rejection, and editors make the final decision. Formats include single-blind, double-blind and open review. Peer review improves quality but does not guarantee that results are correct or reproducible, and it rarely includes reanalysis of raw data. Preprints, posted on servers such as bioRxiv before review, allow rapid sharing but have not yet been vetted. When evaluating peptide literature, it helps to check whether a claim comes from a peer-reviewed journal, a preprint, a conference abstract or marketing material.