How to register a PROSPERO protocol

A PROSPERO protocol is the record you enter in PROSPERO, the international register of systematic reviews with health outcomes, run by the Centre for Reviews and Dissemination at the University of York. It states your question and planned methods before you see the results, which reduces duplicated work and guards against changing the analysis after the fact. PROSPERO itself calls it a registration record and says it is not a full protocol.

Many journals ask for a registration number, and a search of the register is also a quick way to see whether someone else is already working on your topic. This guide covers what a PROSPERO protocol holds, which reviews PROSPERO accepts, what to prepare, and where to register on the official PROSPERO website.

SynthGap is independent and is not affiliated with, endorsed by or approved by PROSPERO, the Centre for Reviews and Dissemination or the University of York. The register itself is at the official PROSPERO website.

What a PROSPERO protocol holds

A PROSPERO record gives the key facts of a planned review: the question, the eligibility criteria, how you will search and screen, the outcomes, how you will collect and combine the data, and who is on the team, who funds it and when it will run. Anyone can read it once it is published, and each record gets a registration number.

PROSPERO says a record is not a full protocol. If you have a full protocol document, you can attach it to the record as a PDF.

What PROSPERO accepts

Accepted: systematic reviews with outcomes of direct relevance to health in humans, registered before data extraction has started. Searching and screening may have begun, but registering before screening is better practice.
Not accepted: reviews that have started data extraction, or that already hold some of the data for a review of individual participant data.
Not accepted: reviews whose outcomes affect health only indirectly, such as educational attainment, and reviews of sporting performance.
Not accepted: traditional literature reviews that use a systematic search but no other systematic review methods, evidence and gap maps, and systematic critical appraisals or reviews of clinical practice guidelines.
Scoping reviews: not accepted at the moment. PROSPERO says this may change.
Students and training projects: PROSPERO asks that the live register is not used for them. Its student project option stores the record and lets you share it with a supervisor, but the record is not published.
The rules change from time to time, so read the eligibility page on the PROSPERO site before you start.

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What to write in a PROSPERO protocol

A review question written as a PICO or another framework, with the eligibility criteria.
The databases and sources you will search, the date range and any language limits, and how you will handle grey literature.
The outcomes: primary and secondary, with their definitions and time points.
How you will screen and extract data (two reviewers, how disagreements are resolved) and which risk of bias tool you will use.
The planned synthesis: what you will pool, with which model, the plan for heterogeneity and subgroup analyses, and how you will judge the certainty of the evidence.
The names, affiliations and contributions of the team, the funder, any conflicts of interest and the timeline.
The stage the review has reached, which the form asks you to state, and whether a full protocol exists.

Where to register

To register a systematic review on PROSPERO, one member of the review team completes the online form on the PROSPERO website while logged in to a PROSPERO account. Registration is free.

As you fill it in, PROSPERO looks for similar reviews that are already registered. If it finds any, it asks why your review is needed, though answering is not compulsory, and your answer, or the lack of one, becomes part of the record.

When the form is complete, the guarantor, usually the senior member of the team, approves it, and every named team member confirms that they take part and that their name and email may be published. The record then gets its registration number and is published at once.

After registration

The registration number starts with CRD. PROSPERO runs automatic checks on the fields, but it does not check the content of the record or peer review it, and it does not endorse it. A record is not a formal publication.

You can amend a record later. PROSPERO keeps a dated audit trail of the changes, and earlier versions stay public. When the review is finished, update the record and add the citation. Quote the registration number in the abstract or the methods.

If PROSPERO does not accept your review

Scoping reviews: register on the Open Science Framework, or publish the protocol in a journal.
Reviews without a direct health outcome: the Open Science Framework or a register for your field.
Reviews that have already started data extraction: register the plan on the Open Science Framework and say in the report what stage the review had reached when you did.
Any review: a protocol article in a journal is another way to make the plan public.

Sources

The rules on this page come from the PROSPERO site, read on 30 October 2026. PROSPERO changes them from time to time, so check the site before you register.

Eligibility for inclusion. PROSPERO, Centre for Reviews and Dissemination, University of York.
How to register a systematic review in PROSPERO. PROSPERO, Centre for Reviews and Dissemination, University of York.

Questions

What is a PROSPERO protocol?

It is the registration record you enter in PROSPERO: your question, eligibility criteria, search and screening plan, outcomes, and plans for collecting and combining data, with the team, funder and timeline. PROSPERO says a record is not a full protocol. A full protocol document can be attached to it as a PDF.

When should I register?

As early as you can. PROSPERO does not accept a review that has already started data extraction, and registering before screening begins is better practice. Registering late weakens the point of registering.

Does it cost anything to register in PROSPERO?

No. PROSPERO says registration is free of charge. You need a PROSPERO account and must be logged in to register.

How long does registration take?

There is no review queue. PROSPERO publishes the record as soon as the guarantor has approved it and every named team member has confirmed, so the time depends mostly on how quickly your team replies.

Can I change my protocol after registering?

Yes. You can amend the record, and PROSPERO keeps a dated audit trail of the changes; earlier versions stay public. Describe the changes and the reasons in the paper too. Undeclared changes undermine the purpose of the protocol.

Can students register a class project?

PROSPERO asks that the live register is not used for student modules or other training projects. It offers a student project option, where the record is stored and can be shared with a supervisor but is not published or found in searches.

Can SynthGap write my PROSPERO protocol?

SynthGap can prepare a draft of the PROSPERO form from a topic it has found, on the Plus and Pro plans. It fills in the fields the topic already answers and marks the rest for you to complete. SynthGap submits nothing and has no access to your PROSPERO account: you check every field and enter the draft yourself on the PROSPERO website.

Keep reading

General methodological guidance, not medical advice. SynthGap's suggestions are AI-generated from the published literature, so verify them before registering a protocol.