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Medical & Clinical Research Journal

Medical & Clinical Research Journal — Peer-reviewed health analysis, supplement safety reviews, and clinical research summaries.

Clinical Trial Status Labels: Recruiting, Active, Completed, and Withdrawn

A status label on a trial registry record describes where a study is in its lifecycle. It does not tell you whether a treatment works, whether you would qualify, or whether you should take part. Those questions depend on the study's eligibility criteria, the study team's screening, and advice from your own clinician. This guide explains what each ClinicalTrials.gov label means, what it does not mean, and how to check whether a record is current.

Editorial note: this article is a plain-language explainer. It has not been peer reviewed or clinically reviewed, and it is not medical advice. See the site's About and Editorial Team and Review Process pages.

The Short Answer

  • Recruiting means the study is currently seeking participants. It does not mean you are eligible or that a spot is open near you.
  • Active, not recruiting means the study is continuing but is not currently enrolling new participants.
  • Completed means the study ended normally. It does not mean the treatment worked, and it does not mean results have been posted.
  • Withdrawn means the study stopped before enrolling its first participant.

ClinicalTrials.gov's protocol definitions describe these labels in nearly these terms (Protocol Registration Data Element Definitions).

What Each Status Label Means

Not yet recruiting

Participants are not yet being recruited. The study may be planned, but enrollment has not opened. The registry applies this wording at the level of individual facilities (see the PBRC ClinicalTrials.gov PRS Guide (2024), hosted by LA CaTS), so confirm the study-wide definition on the registry itself.

Recruiting

Participants are currently being recruited, whether or not anyone has been enrolled yet. The label describes the study's recruitment effort, not your personal eligibility.

Enrolling by invitation

Participants are being selected, or will be selected, from a population the researchers decided on in advance.

Active, not recruiting

The study is continuing. Participants are receiving an intervention or being examined, but new participants are not currently being recruited or enrolled.

Completed

The study has concluded normally and participants are no longer receiving an intervention or being examined; the last participant's last visit has occurred. “Completed” describes how the study ended. It says nothing about whether the intervention was safe or beneficial. Posted results are a separate matter: a record has them only if summary results were submitted to the results database.

Suspended

The study halted early but may resume.

Terminated

The study halted early and will not resume. Participants are no longer being examined or receiving the intervention. For studies that are suspended, terminated, or withdrawn, the registry's definitions call for a brief explanation of why the study stopped, so look for it.

Withdrawn

The study stopped before enrolling its first participant, meaning no one was enrolled.

Unknown

The record's last known status was not yet recruiting, recruiting, or active, not recruiting; its completion date has passed; and the information has not been confirmed within the past two years. ClinicalTrials.gov considers unknown-status studies closed. Do not assume an unknown-status study is still enrolling.

Build a Registry-Status Timeline You Can Verify

Instead of relying on one label, write a short timeline for the study you are reading. Fill each step from the record itself. If a field is blank, write “not stated” rather than guessing. Field names on the website may be worded slightly differently from the descriptions below.

  1. Identify the record. Copy the study's NCT number and title. ClinicalTrials.gov assigns every registered study a unique identification code.
  2. Record the overall status label. Note the exact wording shown and compare it with the definitions above.
  3. Record when the information was last confirmed. The registry tracks the most recent date the sponsor or investigator confirmed the information as accurate. If a study labeled recruiting, not yet recruiting, or active, not recruiting goes two years without confirmation, its status is shown as unknown (ClinicalTrials.gov FAQ).
  4. Record when the record was last updated. An old update date beside a “Recruiting” label is a reason to verify before relying on it.
  5. Record the start and completion dates and whether they are anticipated or actual. Registry definitions use “anticipated” for estimated dates (see this NIAID registration training deck).
  6. Record the reason for stopping, if any. This applies to suspended, terminated, and withdrawn studies.
  7. Record site-level information. Recruitment status can also be listed for each participating facility, so a location may differ from the study-wide label.
  8. Record contact information, if shown. ClinicalTrials.gov does not list contacts for studies labeled active not recruiting, completed, terminated, enrolling by invitation, suspended, or withdrawn (How to Read a Study Record).
  9. Record whether results are posted. A completed study may or may not have posted results.

Warning: a status label is not a treatment recommendation. A “Recruiting” label says nothing about whether an intervention is safe or effective, and a “Completed” or “Withdrawn” label is not evidence for or against one. Registry records describe research plans and their progress. They are not clinical guidance.

Why the Label Can Be Wrong or Out of Date

Study teams supply and update their own record information. A published cross-sectional analysis that examined ClinicalTrials.gov statuses as of 1 January 2017 concluded that recruitment status information was often outdated or wrong (Discrepancies between ClinicalTrials.gov recruitment status and actual trial status). That analysis reflects 2017 data, so treat it as a caution about the limits of self-reported status rather than a current error rate.

For people who work with registry data programmatically, the ClinicalTrials.gov API is refreshed daily Monday through Friday, generally by 9 a.m. Eastern Time, and provides a data timestamp so you can confirm a refresh has finished (ClinicalTrials.gov API). Even fresh data only reflects what the study team has reported.

Who Should Get Professional Advice

  • Anyone considering joining a study should discuss it with their own physician or care team first, and ask the study team directly about risks, procedures, and what participation involves.
  • Anyone thinking about changing, stopping, or delaying current treatment because of a trial listing should speak with their clinician before doing anything.
  • Caregivers reading a record on someone else's behalf should confirm details with the study contact rather than relying on the label alone.

Eligibility is decided by the study team using the criteria in the record. A “Recruiting” label cannot tell you whether you qualify.

What You Can Do Next

  1. Open the record for the study you care about and fill in the timeline above.
  2. Read the eligibility section, compare it with your situation, and bring your notes to your clinician.
  3. If contact details are listed, ask the study team whether the record is current and whether the site near you is enrolling.
  4. If the status is unknown, terminated, or withdrawn, look for the stated reason and for any posted results before drawing conclusions.

Limits of This Guide

Definitions here follow ClinicalTrials.gov. Other registries may use different labels or wording, and registry text can change, so confirm current definitions on the registry itself. For how this site describes its sourcing and independence, see About Med Clin Res.

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