bioRxiv preprints are not peer-reviewed. Every submission passes a basic screening process — checked for plagiarism, offensive or non-scientific content, and research-integrity or biosecurity concerns — before posting, usually within 24-48 hours. That screening confirms a manuscript is a genuine, appropriately scoped scientific report; it does not evaluate whether the methods are sound, the data support the conclusions, or the findings are correct. Formal peer review only happens later, if and when the manuscript is submitted to a journal or an independent review service.
bioRxiv is a free preprint server for the life sciences, operated by the non-profit openRxiv and founded by Cold Spring Harbor Laboratory in 2013, that lets researchers post manuscripts publicly before or during journal submission.
- What bioRxiv’s screening process actually checks
- Screening vs peer review: what’s the difference
- Is medRxiv peer-reviewed too?
- What happens to a preprint after it’s screened
- Common questions about bioRxiv and peer review
What bioRxiv’s screening process actually checks
bioRxiv runs a documented two-step screen on every submission. The first pass is done by in-house staff with scientific and editorial backgrounds, who confirm the manuscript is complete, correctly formatted, and within the server’s life-sciences scope. This stage automatically checks for plagiarism and rules out content that is not a research article — news items, advertisements, policy statements, narrative reviews, and protocols without new data are all excluded.
The second pass is carried out by bioRxiv Affiliates, a network of volunteer principal investigators, who confirm the work is genuine biological research and flag anything that could pose a public-health or biosecurity risk, including what the US National Institutes of Health defines as dual-use research of concern. Overtly identifying patient information is also removed at this stage.
- Plagiarism detection against published and preprint literature
- Confirmation the submission is a scientific research article, not opinion, protocol, or promotional content
- Dual-use and public-health risk screening by volunteer affiliates
- Removal of overt patient- or participant-identifying material
- Scope check — routing clinical-research submissions to medRxiv where appropriate
bioRxiv’s own documentation states that roughly 5% of submissions do not clear this screen and are not posted. Screening typically completes within 24-48 hours — a fraction of the weeks or months a journal’s peer review takes, which is the entire point of a preprint server.
Screening vs peer review: what’s the difference
Screening is a gatekeeping check on form and conduct. Peer review is an expert evaluation of scientific substance — whether the experimental design supports the stated conclusions, whether statistics are applied correctly, and whether the work advances the field. bioRxiv is explicit that no endorsement of an article’s methods, assumptions, conclusions, or scientific quality is implied by its appearance on the server.
| Dimension | bioRxiv screening | Formal peer review |
|---|---|---|
| Who performs it | In-house staff + volunteer affiliates | Independent subject-matter expert reviewers |
| What it checks | Plagiarism, scope, ethics, biosecurity, format | Methodology, data integrity, validity of conclusions |
| Typical duration | 24-48 hours | Weeks to several months |
| Outcome | Posted or rejected (~5% rejected) | Accept, revise, or reject a specific journal submission |
| Result on the record | A citable preprint with a DOI | A certified, published journal article |
Some preprints do receive structured external review while still hosted as preprints — eLife launched its Preprint Review service on bioRxiv in May 2020, and services such as Review Commons operate similarly. These are useful signals, but they are separate, named services layered on top of bioRxiv, not a function of bioRxiv’s own screening.
Independent research (Abdill & Blekhman, cited widely including on Wikipedia) has found that roughly two-thirds of bioRxiv preprints are eventually published in a peer-reviewed journal, and bioRxiv automatically links to the published version once a match is found. That figure is a useful proxy for eventual quality, but it says nothing about the third that are never formally reviewed, and it cannot be applied to any single preprint you are reading today.
Is medRxiv peer-reviewed too?
No. medRxiv, bioRxiv’s sister server for clinical and health-related research, follows the same principle: manuscripts are screened, not peer-reviewed. Because medRxiv covers clinical and public-health topics, its screening is deliberately stricter — submissions undergo additional review for content that could directly influence patient behaviour or clinical practice, and certain categories (such as case reports without a clear scientific contribution) are restricted or excluded outright.
The same “originator, not owner” caution applies here as everywhere in preprint literature: a medRxiv posting is not evidence of clinical validation and should not be treated as equivalent to a peer-reviewed clinical trial report or a regulatory submission.
What happens to a preprint after it’s screened and posted
Once posted, a bioRxiv preprint is permanent and citable. It receives a DOI immediately, cannot be withdrawn once published, and authors can post revised versions that retain the same DOI. Authors typically submit the same manuscript to a journal in parallel or afterwards, where it then enters that journal’s own peer-review process.
bioRxiv operates a “bioRxiv-to-journal” (B2J) transfer service with more than 300 partner journals — including Cell Reports, PLOS Biology, Genetics in Medicine, and Molecular Biology of the Cell — allowing authors to send a screened preprint directly into a journal’s submission and peer-review pipeline without re-uploading files. This accelerates the path from preprint to certified publication but does not shortcut peer review itself.
- Readers can post public comments, moderated to professional standards
- bioRxiv reserves the right to remove plagiarised material or work found to breach research-integrity standards after posting
- A link to the eventual published version is added automatically, usually within a few weeks of journal publication
Common questions about bioRxiv and peer review
Is bioRxiv credible?
bioRxiv is a credible, widely used distribution channel run by a respected non-profit, but credibility of the platform is separate from validity of any individual manuscript. Screening filters out plagiarism and ethical breaches; it does not certify scientific quality, so each preprint must be read critically on its own merits.
Is it okay to cite bioRxiv?
Yes — bioRxiv preprints receive a DOI and are formally citable as part of the scientific record. Most style guides and journals require the citation to note explicitly that the source is an unrefereed preprint, so readers understand it has not passed formal peer review.
Is a preprint a reliable source?
A preprint can be a reliable indicator of ongoing research but is not a validated source in the way a peer-reviewed article is. Reliability depends on the specific manuscript — its methods, transparency, and any subsequent independent review — not on the preprint server’s basic screening alone.
Is bioRxiv considered published?
bioRxiv preprints are publicly posted and citable, but they are not “published” in the traditional peer-reviewed sense used by journals, funders, and most academic assessment exercises. Many institutions and funders explicitly distinguish preprints from peer-reviewed publications in reporting requirements.
Implications for authors, readers, and institutions
For authors, bioRxiv’s fast, lightly gated screening is the trade-off that makes rapid dissemination possible — but it also means responsibility for accuracy sits with the authors, not the platform, until formal peer review occurs. For readers and journalists, the practical rule is definitive: treat unreviewed bioRxiv claims as provisional, check whether a published, peer-reviewed version exists via the automatic journal link, and note preprint status explicitly whenever citing or reporting on one. For institutions building research-integrity or preprint-citation policies, bioRxiv’s own screening criteria — plagiarism, scope, dual-use risk, and patient confidentiality — are a useful documented baseline to reference, precisely because they are narrow and clearly bounded rather than a substitute for peer review.
As preprint volume continues to grow across the life sciences, the distinction between “screened” and “peer-reviewed” is likely to matter more, not less — particularly as overlay review services like eLife’s Preprint Review and Review Commons expand the space between the two.
