No, items listed on PubMed aren’t all peer-reviewed; PubMed is an index that also shows preprints and non-refereed content.
People head to PubMed to grab solid biomedical sources fast. The database is huge and handy, but it blends multiple streams. Some records point to papers that passed external referee checks. Some point to items that did not. The best move is to spot which source a record comes from and then confirm the review path on the publisher page. This guide gives you the signals, the quick checks, and the edge cases so you can cite with confidence.
What PubMed Actually Includes
PubMed is a search layer over several National Library of Medicine collections. It links out to journals, a full-text archive, and book-style works. Because those feeds differ, the review path differs too. Start by noting the source, then read the article type, and finally confirm on the publisher page.
| Source Collection | What It Contains | Peer Review Status |
|---|---|---|
| MEDLINE | Indexed citations from selected biomedical journals | Journals are vetted; many items are peer-reviewed, while letters or editorials may not be |
| PubMed Central (PMC) | Full-text archive; includes publisher files and author manuscripts | Most come from journals that run peer review; PMC also includes preprints under a pilot |
| NIH Preprint Pilot | Selected preprints linked to NIH grants, surfaced in PMC | No external referee checks at posting |
| NCBI Bookshelf | Monographs, reports, and guideline-style material | Editorial or committee review; not journal peer review |
Are Items In PubMed Peer Reviewed? Practical Rules
Think in layers. First, locate the venue. Next, check the article type. Then, scan the record and the publisher page for clear signals. A one-minute pass prevents mis-citations and keeps your references clean.
Layer 1: Identify The Venue
The venue hints at the review path. A “Journal Article” record from a long-running MEDLINE title usually points to external referees. A PMC record that carries a preprint badge signals no referee checks yet. Items from Bookshelf show editorial steps that serve different aims.
Layer 2: Check The Article Type
Many journals publish a mix. A randomized trial, cohort study, or meta-analysis goes through referees. A letter, news note, or viewpoint often runs on editor screening only. The PubMed record shows “Publication Type” tags that steer you toward the likely path.
Layer 3: Verify On The Publisher Page
Open the article link. Look for the “Received,” “Revised,” and “Accepted” dates. Many sites also state the referee model, such as single-blind or open reports. If the page lacks any sign of external checks, treat the piece as unrefereed until you find proof.
Why PubMed Is Not A Peer Review Stamp
PubMed surfaces the biomedical record. It standardizes metadata and links sources, but it does not certify methods or claims. Review happens inside the journals and archives that feed the index. That design gives reach and speed, but it also means users must verify at the item level.
MEDLINE, PMC, And Bookshelf In Plain Terms
Three core streams flow into the search tool. MEDLINE is the primary citations database with subject headings. PMC is the full-text archive that hosts many publisher files and author manuscripts, plus a labeled preprint stream. Bookshelf hosts book-style works. NLM’s guidance for publishers also explains how titles reach these streams and why PubMed spans all three; see the concise overview under For Publishers.
Common Record Types And What They Mean
Here’s a quick map from usual tags to likely review paths. Treat it as a starting point and confirm on the article page.
Research Articles
Original studies list received/accepted dates and show a methods section. In mainstream MEDLINE journals, this kind of paper almost always goes through referees. Still, read the tag set and the publisher page for the final word.
Reviews And Systematic Reviews
Many venues send narrative and systematic reviews to external referees. Records carry tags like “Review” or “Systematic Review.” Some invited overviews run on editor screening only. The publisher page tells you which path applied.
Preprints
Preprints in the PMC pilot show up with clear labels. They share early findings and do not list referee acceptance. When a journal version appears later, the record links versions so you can cite the vetted one. NLM explains this pilot on the NIH Preprint Pilot page.
Editorials, Letters, And News
These sit near research but serve different goals. Many journals screen them in-house. The record will show “Editorial,” “Letter,” or “News.” Treat them as unrefereed unless the site states a formal referee path.
How To Tell If A Specific Record Was Refereed
Use this five-step scan each time you open a record. It takes a minute and keeps your citations solid.
- Read the “Publication Type” tags on the record.
- Click the journal or archive link from the record.
- Look for received/accepted dates on the article page.
- Check the journal’s peer review policy page.
- If it’s still unclear, search the journal site for “peer review,” or open the PDF for a history box.
Journal Vetting Versus Article Peer Review
MEDLINE selects journals through an evaluation process that checks scope, quality, and ethics at the title level. That vetting does not flip every item in those journals into a refereed piece. News items, letters, and corrections still ride a shorter track. NLM also notes that users cannot limit PubMed results to peer-reviewed items, which is why this record-level scan matters.
Filters And What They Do (And Don’t Do)
Filters can help you narrow results by study design, species, age group, and more. A “Randomized Controlled Trial” tag is a strong signal for external referees, but a filter alone does not prove the process. Always open the article page for the dates trio or a policy note.
Linking, Versions, And Record Merging
The index links preprints with later journal versions when the archive supplies the connection. It also links author manuscripts to the final paper when those live in PMC. That merge helps you move from an early draft to the final refereed record without guesswork.
Practical Examples Of Review Signals
Here are quick signals you can spot within seconds. Use them together for a sound call on review status.
| Signal | What You’ll See | What It Suggests |
|---|---|---|
| Dates trio | “Received,” “Revised,” “Accepted” on the article page | External referee process occurred |
| Tag set | “Randomized Controlled Trial,” “Meta-Analysis,” “Systematic Review” | Likely refereed in a journal venue |
| Preprint label | Badge or “Preprint” note in PMC | No referee checks yet |
| Open reports | Peer reports linked next to the article | Refereed, with reports shared |
| Editorial label | Record says “Editorial” or “News” | Editor-screened, not external referees |
Where To Verify Policies
Two spots help you settle any doubt fast. First, the journal’s peer review policy page. Second, NLM’s help pages that explain what shows up in the index and why. NLM states that you cannot limit a search to peer-reviewed items; see this clear note in the NLM knowledge base.
How To Cite Responsibly When Using PubMed
When a preprint and a later journal paper both exist, cite the journal version for claims that need evidence with referee checks. If only a preprint exists, label it as a preprint in your text and in your references. Most styles accept a clean “preprint” flag with a DOI or an archive link. If a Bookshelf report fits your question better than a journal paper, state the series and keep claims within the scope of that format.
Quick Myths And Facts
Myth: every PubMed record passed external referees. Fact: the search tool blends journals, preprints, and books. Myth: a MEDLINE flag means every item is refereed. Fact: that flag sits at the journal level, not the item level.
Tips For Students And Librarians
Create a short checklist and share it in classes and guides. Lead with the five steps above. Add a note on preprints and version linking. Show how to read a record and how to click through to the final page with dates and policy notes. One quick demo in class saves hours of guesswork later.
Short Glossary
Peer Review
Evaluation of a manuscript by subject-area referees before acceptance by a journal.
Editorial Review
Screening by editors for fit and clarity, with no external referee reports.
Preprint
A manuscript posted to a server or archive before any external referee process.
Bottom Line For Quick Decisions
Read the record tags, open the article page, and scan for dates and labels. If anything points to a draft or a commentary, treat it as unrefereed. If you see the dates trio or open reports, you likely have a refereed piece. When in doubt, cite with a clear label or pick a different source.