A plain-language walkthrough of who needs to register a trial, when, how the Protocol Registration and Results System works, and how to keep the record in step with the data you actually collect. General information, not legal advice.
Free sandbox · No credit card · 21 CFR Part 11 aligned
Decide if you must register
Law, funder, journal
Get a PRS account
Via your organisation
Enter the record
From the approved protocol
Release for review
Status must be Released
Respond to review comments
Update and report results
As your study progresses
What to know before you start
Who must register
People often ask whether they have to register a trial, and the answer is that three separate sources can each say yes, with different deadlines. The first is the law. In the United States, FDAAA 801 and its implementing rule, 42 CFR Part 11, require registration of applicable clinical trials, a defined category that covers many interventional studies of FDA-regulated products. Whether your study is an applicable clinical trial depends on that definition, and ClinicalTrials.gov publishes guidance and a checklist for working it out. The rule's timing for registration is within 21 days of the first participant being enrolled, where enrolled means the participant, or their legally authorized representative, has agreed to take part after the consent process.
The second source is the funder. NIH-supported trials have their own registration and reporting expectations, and other funders add their own conditions to grants. Read the grant terms rather than assuming they match the legal rule. The third is the publishing route. The ICMJE recommends that member journals require public registration at or before first participant enrolment as a condition of considering the results for publication, and many journals outside the committee follow similar policies. For a startup that hopes to publish, this is often the deadline that actually binds.
The practical advice is therefore simple: if your trial is interventional and you intend to publish, register before you enrol. It is quicker than reasoning through three rule sets, and it avoids a situation in which a good trial cannot be published. If you are unsure whether the law applies to you, ask your adviser. The running your first clinical trial roadmap shows where registration sits in the sequence.
The process
Registration happens in the Protocol Registration and Results System (PRS). Exact screens change, so use the PRS help pages as the authority.
The record is entered from the protocol, the consent documents and the ethics or IRB application. Use the final or near-final versions so the record matches what will be run.
Accounts are generally linked to an organisation. If your institution has a PRS administrator, request an account through them. Independent sponsors and small companies can request an organisation account directly from ClinicalTrials.gov; follow the current instructions on the site.
The responsible party is the sponsor or a qualifying principal investigator. At many institutions the responsible party is also the person who owns the record. Agree this early, because the responsible party is accountable for the record's accuracy.
Log in, create a new record and complete the sections: study identification, status, design, arms and interventions, outcome measures, eligibility, locations and contacts. Use the unique protocol identifier from your protocol.
Use the preview and error checks, then release. ClinicalTrials.gov will not process a record until its status is Released.
ClinicalTrials.gov staff review released records for quality. If they find problems, the record comes back with comments. Fix them and release again.
Once posted, the record has an NCT number. Add it to your protocol, consent documents where required and trial master file, and quote it in publications.
What goes in the record
The fields below map directly to decisions you already made for the study. Entering them is mostly transcription, if the protocol is clear.
| Record section | Typical content | Where it comes from in your study |
|---|---|---|
| Study identification | Titles, unique protocol ID, sponsor | Protocol title page |
| Design | Allocation, masking, model, phase | Protocol design section |
| Arms and interventions | Groups, doses, comparators | Protocol interventions, randomization plan |
| Outcome measures | Primary and secondary measures with time frames | Endpoints; the same measures you capture on your eCRFs |
| Eligibility | Inclusion and exclusion criteria, ages, sex | Protocol eligibility, screening form |
| Locations and contacts | Sites, recruitment status, contacts | Site list, site activation |
| Status dates | Start, primary completion, completion | Actual visit dates, tracked from enrolment and visit data |
This is a summary, not the official data element list. See the ClinicalTrials.gov PRS help for the current definitions.
Build the eCRFs for your registered primary and secondary outcomes in the free sandbox, test them, then go live. No credit card, pay only when live.
After registration
Registration is not a one-off. Your record should stay current while the study runs: recruitment status changes, sites open or close, and a protocol amendment may change outcomes or eligibility. A mismatch between the registered primary outcome and what you actually analyse is one of the first things a reviewer or reader notices. Build a habit: whenever the protocol changes, ask whether the registry record needs to change too.
This is where the data system matters. The primary and secondary outcome measures on the record should each correspond to specific eCRF fields or ePRO questionnaires, and your clinical trial endpoints should be traceable from record to protocol to form to export. In Capture, forms move through a draft-to-approved lifecycle and are locked for live use, and the field-level audit trail records the timestamp, user, old value, new value and reason for every change, so you can show what was collected and when. The case report form entry explains how forms and endpoints connect.
Dates are another point to get right. The primary completion date is when the final participant was examined or received an intervention for the purposes of final collection of data for the primary outcome, so it is determined by your visit data, not by the date you close the database. Keep a clean record of last visits per participant. Capture exports, including by-site and date-range filtered CSV or Excel files with an automatic data dictionary, give your statistician the material for results reporting; Capture does not prepare the registry submission itself.
Common pitfalls
Register before the first participant is enrolled so that you meet journal and legal timing together.
State each outcome with the measure, the metric and the time frame; this is also what your analysis plan will need.
If the protocol amends an outcome, update the record and keep the history; do not leave them to drift apart.
Agree who is accountable for the record and for updates before submission.
For applicable clinical trials, results are due no later than one year after the primary completion date, with limited provisions for delay; plan your analysis timeline against it.
Add it to the protocol, consent where appropriate and any publication.
Other registries and context
ClinicalTrials.gov is widely used, but it is not the only acceptable registry. ICMJE accepts registration in ClinicalTrials.gov or in a primary register of the WHO International Clinical Trials Registry Platform that meets the minimum registration dataset. European trials may also have registration duties under EU rules, and national requirements differ. If you run a multi-country study, ask your regulatory adviser which registries apply and whether one record can satisfy more than one purpose.
Registration sits alongside the other pre-start tasks: ethics approval, any regulatory clearance, site contracts and data system testing. Registration normally takes place once the protocol is final enough to describe, and the IRB submission checklist and institutional review board entries cover approvals. For the wider project plan, see how to write a clinical trial protocol and the ICH E6(R3) guide.
Finally, a word on tone. Registration exists to make trials transparent: so that readers can see what was planned, and so that results are not selectively reported. A tidy registry record is therefore both a compliance task and a credibility asset for a startup that will one day ask investors, regulators and journals to trust its data.
Get a Protocol Registration and Results System (PRS) account through your organisation or request one from ClinicalTrials.gov, create a record, enter the required data elements from your protocol, preview it and release it. ClinicalTrials.gov reviews released records and may return them with comments to fix before posting.
Under US rules for applicable clinical trials, within 21 days after the first participant is enrolled. ICMJE-following journals expect registration at or before first participant enrolment, which is the safer target. This is general information, not legal advice.
It is the category of studies covered by FDAAA 801 and 42 CFR Part 11, covering many interventional studies of FDA-regulated products. Whether yours qualifies depends on the rule's definition; use the ClinicalTrials.gov guidance and your regulatory adviser to decide.
For applicable clinical trials, results are generally due no later than one year after the primary completion date, with limited provisions for delay. Check the current rule for your study.
Not always. ICMJE accepts ClinicalTrials.gov or any primary registry of the WHO ICTRP that includes the minimum registration dataset. Other laws or funders may require a specific registry.
No. Capture does not submit your registration. It holds your study data, forms, audit trail and exports, so the outcomes you register can be traced to the fields you actually collect.
Yes. Keep status, sites and outcome details current, and update the record when a protocol amendment changes something it describes.
Keep exploring
Running your first clinical trial
Where registration fits in the roadmap.
How to write a clinical trial protocol
The document the record is built from.
IRB submission checklist
Approvals that come with registration.
ICH E6(R3) guide for clinical trial teams
GCP context for your study.
Clinical trial endpoints (glossary)
Defining outcomes you will register.
Set up your study in the free sandbox, test every form and go live when your registration and approvals are in. No credit card, pay only when live.