PubPeer

PubPeer

PubPeer is an independent, web-based platform where anyone can post public comments — anonymously or under their own name — on papers already published in the scholarly literature, identified by DOI, PubMed ID, or a title/author search. It is a venue for open, informal post-publication commentary, not a peer-review, editorial, or investigative body: it has no authority to correct, retract, or adjudicate a paper, and the mere existence of a PubPeer comment thread on a paper is not, by itself, evidence of research misconduct.

ByCASRAI Editorial Board

· Last updated 17 Jul 2026

Worked examples

Is an instance

A PubPeer comment thread, attached to a paper's DOI, that identifies apparent duplication between two supposedly-distinct western blot images in a figure — the kind of concern most commonly raised on the platform.

Is an instance

A retraction notice that credits, with the commenter's permission, an anonymous PubPeer user for having first raised the concern that led to the investigation — the crediting practice COPE's retraction guidance recommends.

Looks similar, but isn't

Not an instance

The journal's own expression of concern or retraction notice — the formal editorial record issued only after a publisher or journal investigation, distinct from the public PubPeer discussion that may have prompted it.

Not an instance

A university's confidential research-misconduct investigation report — a procedurally governed inquiry with defined findings and appeal rights, categorically different from an open, largely unmoderated public comment thread.

PubPeer is an independent website that hosts public, post-publication commentary on scholarly papers — comments can be attached to almost any paper identified by its DOI, PubMed ID (PMID), or via a title/author search, and can be posted anonymously or under a real name. It operates completely independently of any publisher, journal, funder, or standards body, CASRAI included, and has no formal editorial, investigative, or corrective authority over the papers discussed on it.

Who runs it

PubPeer was launched in 2012 by neuroscientist Brandon Stell as an online successor to the in-person “journal club” — a place where anyone, not just a paper’s original peer reviewers, could discuss a published article publicly. Anonymous commenting, formalized in March 2013, became the site’s defining and most consequential feature. Stell and two co-founders, George Smith and Richard Smith, ran the site anonymously until August 31, 2015, when they publicly revealed their identities and announced the PubPeer Foundation, a California-registered nonprofit public-benefit corporation that has since obtained 501(c)(3) status in the United States and now operates the site. CASRAI has no institutional, financial, or governance relationship with PubPeer or the PubPeer Foundation — it is cited here strictly as an external resource, the same way CASRAI content cites other independent research-integrity bodies such as Retraction Watch or COPE.

How commenting works

Comments are attached to a paper by its DOI or PMID, or found via a title/author search, and can target the paper as a whole or a specific figure or panel within it — a substantial share of PubPeer discussion concerns apparent image manipulation or duplication in figures, alongside statistical anomalies and other data concerns. Since 2016, PubPeer’s moderation policy has required that comments “use only facts that can be publicly verified” rather than unsubstantiated accusation. First-time and pseudonymous commenters are moderated before their comments appear publicly; established, registered users’ comments generally post immediately. A free browser extension, available since 2014, flags papers with existing PubPeer discussion while a reader browses a publisher’s site or PubMed, without requiring a manual PubPeer search.

PubPeer’s role in the research-integrity ecosystem

PubPeer sits at the informal end of a much longer pathway that CASRAI’s guide to post-publication peer review covers in full. A concern raised there — like one raised directly to an editor, an institutional research-integrity office, or a journal’s own screening — is one possible input into a formal editorial process, not a substitute for it. Bodies working in research integrity, including the Committee on Publication Ethics, whose decision framework CASRAI covers in COPE Flowcharts Explained, set out how that process should run once a concern is credible enough to investigate: an editor’s initial assessment, an investigation often involving the author’s institution, and — only if substantiated — a formal outcome such as a correction (corrigendum), an expression of concern, or a retraction, as described in CASRAI’s guide to how a retraction actually happens. COPE’s current retraction guidance explicitly recommends crediting a third party — including a PubPeer commenter — who raised a valid concern, with their permission, once a retraction is issued. Academic studies of retracted papers have repeatedly found meaningful overlap between papers later retracted and papers that had prior PubPeer discussion, though the exact proportion varies considerably by study design, discipline, and time period studied, and a prior PubPeer thread is far from universal among retracted papers. See also CASRAI’s guides on paper mills and tortured phrases and how a research misconduct investigation actually works, and the dictionary entries for image duplication and paper mill — recurring subjects of PubPeer discussion.

What a PubPeer thread is not

Two distinctions matter for accurate and fair use of PubPeer as a source. First, PubPeer comments are not themselves peer-reviewed: the site’s post-2016 moderation policy screens for publicly verifiable factual content, not for accuracy, completeness, or fairness to a paper’s authors, and a comment can be technically accurate about a figure while still misjudging its cause — image errors, for instance, range from innocent mislabeling to deliberate fabrication, and a PubPeer comment does not distinguish between them. Second, and more consequentially, a PubPeer discussion existing on a paper is not equivalent to a finding of research misconduct. A misconduct finding requires a formal institutional or publisher investigation, conducted under defined procedure with the accused author’s right to respond — exactly the process CASRAI’s guide to how a research misconduct investigation actually works and research misconduct case studies guide both describe. The stakes of conflating the two are not hypothetical: in Sarkar v. Doe, a Wayne State University researcher sued anonymous PubPeer commenters for defamation after losing a job offer; a Michigan trial court initially ordered PubPeer to unmask one commenter, but the Michigan Court of Appeals reversed that order in December 2016, protecting commenter anonymity while allowing the underlying defamation claim to proceed against the one already-identified commenter — see the ACLU’s case summary. Treat a PubPeer thread as a starting point for a question, not as a conclusion.