Can Preprints Be Cited? Thesis Rules, APA Format and Checks

Can preprints be cited in a thesis? Yes. APA Style has a reference format for preprints, and bioRxiv says its preprints "can be cited using their digital object identifier". The catch is that arXiv, bioRxiv and medRxiv do not peer review what they post, so label each preprint clearly and check its status before you submit.

APA's own advice is short: "Ideally, use and cite the final, published version of a work." It adds that if you used the preprint version, you cite that version. The rest of this guide shows how to decide, how to format the reference, how to word the sentence around it, and what to check on each server.

Can preprints be cited? What the servers themselves say

You can. arXiv and bioRxiv both explain how to cite what they post, and each gives a preprint a lasting identifier. None of these servers peer reviews what it posts, and each says so plainly.

• arXiv: "the arXiv moderation process is not a peer-review process", according to its moderation page. Moderators review each submission's content and category against arXiv's policies.
• bioRxiv: "Articles are not peer-reviewed, edited, or typeset before being posted online", says its about page. The page also states there is no endorsement by Cold Spring Harbor Laboratory of an article's methods, conclusions or scientific quality.
• medRxiv: uses the same words about peer review, and adds that preprints "should not be relied on to guide clinical practice or health-related behavior", according to its about page.

So the answer to "can you cite a preprint" is yes, as long as your reader can see it is a preprint. University guidance makes the same point about status: the University of Oxford's Bodleian Libraries preprint guide states that "A preprint has not been peer reviewed".

Can you use preprints in a thesis? A decision table

Use a preprint when it is the best available evidence for a claim and you can name its status. Avoid it when a peer-reviewed source makes the same point, or when the claim carries real weight in your argument.

Situation	What to do
The preprint is the only source for a recent finding you need	Cite it and mark it as a preprint in the sentence and the reference. Avoid building a central claim on it alone
A published journal version now exists	Cite the published version, as APA advises, unless you relied on something only the preprint contains
The claim is clinical or about health behaviour	Look for peer-reviewed support first; medRxiv itself warns against relying on preprints for clinical practice
The preprint has been withdrawn	Do not rely on it; remove the claim or explain the withdrawal
It is your own preprint in a thesis made of papers	Follow your university's rules for publication format theses (see the Sheffield example below)
You are unsure	Ask your supervisor, and keep a note of the version you read and the date you read it

If a published version appears, check that your claim still matches it before you change anything. Our guide on how to cite a preprint once the published version is out covers the swap step by step.

What university rules say about preprints

University rules differ, so read your own graduate school's thesis regulations before relying on any example here. Two named examples show the kind of wording to look for.

The University of Sheffield's thesis formats page lets a publication format thesis include papers that "may have already been published, be accepted for publication, or be planned for submission for publication". On pagination, it notes this "might necessitate including separate versions of the papers, rather than inserting pre-prints". The sentence before it says that, where possible, page numbering should flow through the whole thesis. So a paper you posted as a preprint can still be part of the thesis, but you may need a separately formatted version of it.

Oxford's Bodleian guide, linked above, advises authors to "Identify a reputable preprint server suitable for your field". That is a test you can apply to the preprints you cite too. Neither page bans citing preprints or gives a blanket permission, so your handbook and your supervisor have the final word.

How to cite a preprint in APA 7

In APA's examples, the title is in italics and the archive name comes straight after it. Here is its PsyArXiv example, copied from APA Style:

Hampton, S., Rabagliati, H., Sorace, A., & Fletcher-Watson, S. (2017). Autism and bilingualism: A qualitative interview study of parents' perspectives and experiences. PsyArXiv. https://doi.org/10.31234/osf.io/76xfs

The in-text citations follow the usual author and date pattern, for example (Hampton et al., 2017) or Hampton et al. (2017). APA notes that you can "Follow the same format for other preprint archives". Neither APA example adds a bracketed label such as [Preprint]. APA also notes that preprints "may or may not be peer reviewed", so check the status of the one you cite.

Here is a fill-in template that follows the same pattern. Replace every placeholder in brackets with details from the preprint's own page:

[Surname], [Initial]., & [Surname], [Initial]. ([Year]). [Title of the preprint in sentence case]. [Archive name, such as arXiv, bioRxiv or medRxiv]. [https://doi.org/DOI or the archive URL]

Record the version you read

Preprints change, so write down which version you used. arXiv's versions page says authors "can cite each version with the full identifier that includes the version number", in the form arXiv:YYMM.NNNNNvX. On bioRxiv, revised versions keep the same DOI, and its FAQ says you can cite a specific version "by adding the version-specific URL".

Can you cite preprints in thesis text without weakening the argument

Yes, if the sentence tells the reader what kind of evidence it is. A short status phrase does the work, and it also prepares you for the question an examiner may ask in a viva.

Here are sentence patterns you can adapt. Fill in the brackets with your own details:

• "A preprint by [Author] ([Year]), not yet peer reviewed at the time of writing, reports [finding]."
• "Early evidence from a preprint ([Author], [Year]) suggests [finding]; this is consistent with the peer-reviewed work of [Author] ([Year])."
• "[Finding] has so far been reported only in a preprint ([Author], [Year]), so this thesis treats it as provisional."

If you are asked about a preprint in your viva, a clear answer has three parts. Say why you cited it, what its status was when you submitted, and whether your argument still stands without it. For example: "I cited it because it was the only study testing [X]. I checked it a week before submission and it was still unreviewed, so my claim does not depend on it alone."

Check every preprint before you submit

Preprints can be revised, published or withdrawn after you cite them. Run this check on each one in your reference list in the final month, and again before your viva.

1. Open the preprint page and note the latest version. On arXiv, each replacement creates a new version, and every earlier version stays public as "a permanent part of the scientific record".
2. Look for a published version. bioRxiv says it "will usually automatically add a link to the published version". On arXiv, authors add the journal reference themselves, and arXiv's journal reference page says this creates no new version. A missing link does not prove the paper is unpublished.
3. Search the title in a database. Crossref's preprint documentation says the preprint publisher will update its metadata to link the preprint to the DOI of the accepted manuscript or version of record.
4. Check for withdrawal. arXiv's withdrawal page says a withdrawal creates a new version stating that the paper "has been withdrawn, and by whom". bioRxiv adds a withdrawal statement and a "Withdrawn" watermark to the PDF.
5. Decide and record. Keep, swap for the published version, or remove. Write the date you checked next to each reference.

The same habit is worth applying to every reference, not only preprints. Our guide on how to verify references walks through it.

What Thesisroom does with this

Citation Check looks each reference up in eight registries: Crossref, OpenAlex, Semantic Scholar, PubMed, Retraction Watch, DOAJ, CORE and Unpaywall. It shows which references it could verify, which are retracted, and which need checking by hand. It never calls a reference fabricated, and deciding whether a preprint is strong enough to cite stays with you.

After that, Reference Watch re-checks your verified sources every week and alerts you when one changes, such as a retraction. If you only want to test a pasted reference list, the free citation checker needs no account.

Frequently asked questions

Can you cite a preprint in APA?

Yes. APA Style gives a preprint format: authors, year, the title in italics, the archive name, then the DOI or URL. APA advises citing the final published version when you can, and the preprint when that is the version you used.

Are preprints peer reviewed?

Not on these servers. arXiv says its moderation "is not a peer-review process", and bioRxiv and medRxiv say articles are not peer reviewed, edited or typeset before posting. Some later appear in journals after peer review.

Can I cite an arXiv paper in my thesis?

Yes. Cite it like any preprint, with the arXiv identifier or DOI, and note the version you read. arXiv lets authors cite a specific version using the full identifier with the version number, in the form arXiv:YYMM.NNNNNvX.

What if the preprint I cited was later published?

APA advises citing the final published version where possible. Check that your claim still matches the published text, then update the reference. Keep the preprint only if you relied on something the published version does not contain.

What if a preprint I cited was withdrawn?

Stop relying on it. On arXiv and bioRxiv, earlier versions stay visible with a withdrawal notice, so the text will not simply vanish. Remove or rewrite the claim, or explain the withdrawal if the history matters to your argument.

Can my own preprint go in my thesis?

It can, but it depends on your university. Sheffield's publication format thesis can include papers planned for submission, and its page says continuous page numbering may mean including separate versions rather than inserting preprints. Check your own regulations and any journal conditions.

Sources

• APA Style: Preprint article references
• arXiv: Moderation
• arXiv: Versions
• arXiv: Withdrawals
• arXiv: Adding journal reference and DOI
• bioRxiv: About bioRxiv
• bioRxiv: Frequently asked questions
• medRxiv: About medRxiv
• Crossref: Posted content (includes preprints)
• University of Oxford, Bodleian Libraries: Preprints
• University of Sheffield: Thesis formats

How this guide was made: Thesisroom drafted this guide with the help of AI writing tools, then checked every fact, figure and source by hand against the references linked above.