How Long Does Peer Review Take? Timeline & Delays

How Long Does Peer Review Take? Journal Review Timelines Explained

Submitting a research manuscript to an academic journal is an important milestone, but waiting for the editorial decision can be frustrating. Authors often check their submission dashboard repeatedly, wondering whether the review process is progressing normally.

So, how long does peer review take?

Peer review commonly takes several weeks to several months, although the actual timeline varies considerably by journal, discipline, reviewer availability, and manuscript complexity. Some journals reach an initial decision quickly, while others require extended reviewer recruitment, multiple assessments, or additional revision rounds.

It is also important to distinguish between the time taken for external peer review and the total time from manuscript submission to final acceptance.

A paper may receive its first decision within weeks yet take several additional months to complete revisions and receive final approval.

This guide explains typical peer review timelines, each stage of the journal publication process, common reasons for delays, manuscript status meanings, and when authors should contact journal editors.

How Long Does Peer Review Take on Average?

There is no single average review time that accurately represents every academic journal.

As a broad planning guide, authors often allow several weeks to a few months for a first decision involving external review. However, this is not a universal benchmark or a publisher-wide average.

Some journals provide decisions much sooner, while certain manuscripts remain under evaluation for several months.

The time required depends on several factors, including:

• The availability of qualified reviewers.
• The journal's editorial workload.
• The research discipline.
• The complexity of the manuscript.
• The number of reviewers required.
• Conflicting reviewer recommendations.
• Whether additional evaluations are needed.

A journal may also reject a manuscript after initial editorial screening without sending it for external peer review.

Consequently, a very short time to first decision does not necessarily mean that a manuscript underwent rapid expert evaluation.

The most reliable estimate for a specific submission is the journal's published decision-time statistics, interpreted according to the metrics it reports.

Peer Review Timeline: From Submission to Decision

The journal publication process involves several distinct stages.

These stages do not necessarily occur in a perfectly linear sequence.

A manuscript may return to reviewer recruitment after a report is received, or undergo several rounds of revision before acceptance.

1. Initial Editorial Screening

After submission, the manuscript typically undergoes an initial assessment by the journal's editorial team.

The editor examines whether the paper fits the journal's scope and satisfies basic publication requirements.

This screening may include consideration of originality, reporting completeness, research ethics, and scientific suitability.

If the manuscript is not appropriate for the journal, the editor may issue a desk rejection without sending it to external reviewers.

A manuscript that passes the initial screening proceeds toward reviewer selection.

The screening period depends on the journal's workload and editorial procedures.

Authors should not assume that a manuscript remaining with the editor for several days indicates a problem.

2. Reviewer Selection and Invitation

Reviewer recruitment is one of the most unpredictable stages of peer review.

Journal editors must identify researchers with the relevant expertise, invite them to assess the manuscript, and obtain their agreement.

Potential reviewers may decline because of existing commitments, conflicts of interest, or insufficient subject expertise.

When this happens, the editor must invite additional candidates.

Specialized manuscripts can be particularly challenging because relatively few researchers may have the required methodological or technical knowledge.

For example, a paper combining electrical power system modeling with advanced machine learning may require reviewers familiar with both fields.

Finding those experts can take longer than evaluating a manuscript within a widely studied research area.

Elsevier's Editorial Manager guidance confirms that reviewer availability is a major influence on the time required for peer review.

3. External Peer Review

Once reviewers agree to participate, they examine the manuscript and prepare written assessments.

Reviewers may evaluate the originality, research design, analysis, findings, interpretation, and scholarly contribution of the work.

The time allowed for an individual report varies by journal.

Wiley's editorial guidance recommends that reviewers generally receive at least two weeks to complete their reports. It also describes specific workflows using a 14-day deadline with an additional seven days available.

However, the deadline assigned to one reviewer should not be confused with the entire manuscript review timeline.

The journal may still be recruiting another reviewer while the first expert is completing a report.

Some reviewers may also request extensions because of teaching responsibilities, research commitments, or unexpected circumstances.

4. Editorial Assessment of Reviewer Reports

After reviewers submit their reports, the handling editor examines their recommendations and comments.

The editor considers whether the manuscript satisfies the journal's publication standards and whether the authors should address any identified concerns.

Sometimes the reviewers disagree.

For example, one reviewer may recommend minor revisions while another raises serious methodological questions.

The editor may resolve the disagreement independently or request another expert assessment.

This can extend the process even after the required number of reports has initially been received.

The final editorial recommendation should reflect the scientific evidence and journal standards rather than a simple vote among reviewers.

5. First Editorial Decision

The first decision is the journal's initial formal response to a manuscript submission.

Depending on the journal, possible outcomes include rejection, minor revision, major revision, or acceptance.

A first decision does not always end the publication process.

Many manuscripts require revisions before they can receive final acceptance.

For example, a paper receiving a major revision decision may need substantial methodological clarification or additional analysis.

The authors then revise the manuscript and submit a point-by-point response.

The revised version may return to reviewers for another assessment.

Therefore, the time to first decision and the time to acceptance can differ substantially.

What Does “Under Review” Mean?

The status Under Review generally indicates that the manuscript has entered the journal's external review workflow.

However, it does not necessarily mean that all invited reviewers are actively evaluating the paper at that moment.

According to Elsevier, the status may cover reviewer invitations, ongoing evaluations, and situations where the editor is seeking additional reviews.

For example, a manuscript may remain Under Review while the journal is trying to recruit a replacement reviewer.

It may also return to that status after the editor receives conflicting reports and requests another opinion.

For this reason, a long Under Review period does not automatically indicate a negative publication outcome.

Common Manuscript Submission Statuses Explained

Submission systems display different terms to describe manuscript progress.

The exact names and timing of these statuses vary across publishers and journal systems.

Some statuses may be skipped or revisited.

Authors should consult their specific publisher's submission guidance when interpreting unfamiliar labels.

How Long Does a Manuscript Stay Under Review?

A manuscript may remain Under Review for several weeks or months.

The length of this stage depends on whether reviewers are available, how quickly reports arrive, and whether the editor requests additional evaluations.

For example, consider a hypothetical timeline:

• Week 1: The manuscript passes initial screening.
• Week 2: The editor sends reviewer invitations.
• Week 3: Two reviewers agree to assess the paper.
• Weeks 4–6: The reviewers examine the manuscript.
• Week 7: One reviewer submits a report.
• Week 8: The second review arrives.
• Week 9: The editor prepares a decision.

This illustration shows why a manuscript can spend multiple weeks under review even when the individual reviewing assignments are relatively short.

It is not a prediction of how any particular journal will handle a submission.

Why Does Peer Review Take So Long?

Several factors can delay manuscript evaluation.

Difficulty Finding Reviewers

Journal reviewers are often active researchers with significant professional responsibilities.

Some invitations go unanswered, while others are declined.

Editors may need to contact several experts before securing the required reviews.

Complex Research Methods

Manuscripts involving advanced statistical models, technical simulations, or multidisciplinary methods may require additional expertise.

Reviewers may also need more time to evaluate complex supplementary materials.

Conflicting Reviewer Reports

When reviewers provide substantially different assessments, editors may request another opinion.

This can add time to the review process.

Reviewer Deadline Extensions

Reviewers may request more time because of research, teaching, professional travel, or unexpected circumstances.

Journals must balance thorough evaluation with timely editorial decisions.

Editorial Workload

Editors frequently manage multiple submissions while maintaining research or clinical responsibilities of their own.

A heavy workload can delay reviewer assignments or decision preparation.

Additional Revision Rounds

A manuscript requiring major revision may undergo a second or third round of evaluation.

Each additional cycle contributes to the time from submission to final acceptance.

How Long Does Peer Review Take After Major Revision?

A major revision decision usually indicates that the editor sees issues requiring substantial changes before a final publication decision can be made.

After the authors submit the revised manuscript, the editor may evaluate it directly or send it back to external reviewers.

The timeline depends on the changes requested and whether the same reviewers are available.

If the reviewers need to reassess extensive new analyses, the second round may take longer than an editorial check of minor corrections.

Major revision does not guarantee acceptance.

The final outcome depends on whether the revised manuscript adequately addresses the scientific and editorial concerns.

How Long Does Peer Review Take After Minor Revision?

Minor revision generally involves more limited corrections.

Examples include clarifying terminology, improving figures, correcting references, or refining explanations.

Some editors assess these changes without sending the paper back to external reviewers.

Other journals may request another reviewer assessment.

As a result, minor revisions can sometimes be processed relatively quickly, but there is no universal turnaround time.

Authors should follow the editor's instructions and provide clear responses explaining the changes made.

What Does “Required Reviews Completed” Mean?

In Elsevier's Editorial Manager, Required Reviews Completed indicates that the target number of reviewer reports has been received.

The handling editor can then assess the reports and determine the appropriate next step.

However, the status does not mean that the manuscript has been accepted.

The editor may need additional time to compare recommendations, resolve conflicting assessments, or consult another editor.

The manuscript may even return to Under Review if another evaluation is needed.

Therefore, authors should interpret this status as progress in the workflow rather than an indicator of the likely decision.

What Does “Decision in Process” Mean?

Decision in Process means that editors have begun preparing or entering an editorial decision within the submission system.

The decision may require confirmation or further review before it is released to the author.

It does not reliably indicate whether the manuscript will be accepted, rejected, or returned for revision.

Elsevier states that manuscripts can return to earlier stages if editors determine that further review is necessary.

The author receives the actual result once the journal sends its formal decision communication.

Does a Long Peer Review Mean Rejection?

No. A long peer review period does not necessarily mean that a manuscript will be rejected.

Delays may arise from reviewer recruitment, competing academic commitments, editorial workload, or disagreement between reviewers.

A paper may remain under review for an extended period and eventually receive a favorable decision.

Conversely, a manuscript may be rejected quickly during editorial screening.

The duration of the process alone is therefore not a reliable indicator of manuscript quality or publication outcome.

Authors should focus on official editorial communication rather than attempting to predict the decision from dashboard statuses.

When Should You Contact the Journal Editor?

Authors may contact the editorial office when their manuscript has remained at the same stage substantially longer than the journal's published or communicated review timeframe.

If the journal reports an expected first-decision time, use that figure as the initial reference.

If no timeline is available, an inquiry after a prolonged period without meaningful updates may be reasonable.

Before contacting the editor:

1. Check the current manuscript status.
2. Review the journal's published turnaround information.
3. Check your email for requests or notifications.
4. Confirm that no action is required from you.
5. Prepare your manuscript identification number.

Keep the message concise and professional.

Avoid sending repeated inquiries at short intervals unless an urgent issue requires attention.

Sample Email to Ask About Peer Review Status

Subject: Inquiry About Manuscript Status — [Manuscript ID]

Dear Editorial Office,

I hope you are well.

I am writing to inquire about the current status of our manuscript, "[Manuscript Title]," submitted on [Submission Date], under manuscript ID [ID].

The submission has remained under review for some time, and I would appreciate any update you can provide regarding its progress or anticipated next steps.

Thank you for your time and assistance.

Kind regards, [Corresponding Author Name]

This wording requests clarification without implying that the editor or reviewers have acted improperly.

How Can Authors Reduce Unnecessary Review Delays?

Authors cannot control reviewer availability, but they can avoid preventable submission problems.

Before submitting, carefully follow the journal's author guidelines.

Ensure that figures, tables, references, declarations, and supplementary materials are complete.

Select a journal whose subject area fits the manuscript.

Respond promptly to editorial requests and submit revisions within the assigned deadlines.

When suggesting reviewers is permitted, recommend qualified specialists without relevant conflicts of interest.

Finally, provide organized responses to reviewer comments.

A clear revision letter can help editors and reviewers assess changes efficiently.

These practices may reduce avoidable administrative delays, although they cannot guarantee a faster decision.

Frequently Asked Questions About Peer Review Timelines

How many weeks does peer review usually take?

Some manuscripts complete external review within several weeks, while others require months. The timeline depends on the journal, reviewers, manuscript complexity, and editorial procedures.

Why has my paper been under review for two months?

The journal may still be collecting reviewer reports, replacing unavailable reviewers, or considering additional evaluations. Two months under review does not, by itself, indicate acceptance or rejection.

Can peer review take six months?

Yes. Some submissions remain in the review process for six months or longer, especially when reviewer recruitment is difficult or additional assessments are needed.

Does Under Review mean the paper passed editorial screening?

In many submission systems, it indicates that the manuscript has entered the external review workflow. However, status definitions vary, and it does not mean the paper is guaranteed to proceed to publication.

Is Required Reviews Completed a good sign?

It indicates that the required review reports have been received, but it does not predict whether the decision will be positive or negative.

Does Decision in Process mean rejection?

No. It indicates that an editorial decision is being prepared or confirmed. Acceptance, revision, and rejection are all possible outcomes.

Is major revision a good sign?

Major revision means the editor has invited substantial changes rather than issuing a final rejection at that stage. However, acceptance remains uncertain and depends on the revised manuscript.

When should I email the editor about a delayed manuscript?

Contact the editorial office when the manuscript has substantially exceeded the journal's stated timeframe or has remained unchanged for an unusually long period. Include the manuscript ID and request a brief status update.

Conclusion

Understanding how long peer review takes helps researchers set realistic expectations when submitting manuscripts to academic journals.

The review process can last several weeks or months depending on reviewer availability, editorial workload, research complexity, and the number of required assessments.

Importantly, time to first decision, external review duration, and time to final acceptance are different measures.

Statuses such as Under Review, Required Reviews Completed, and Decision in Process indicate stages of editorial work rather than predicting the outcome.

Authors can reduce unnecessary delays by preparing complete submissions, responding promptly to revisions, and following journal instructions.

When a manuscript exceeds the publication's expected timeframe, a polite inquiry to the editorial office is an appropriate way to request clarification.