National Library of Medicine
U.S. National Library of Medicine
Write to the Help Desk
NLM Support Center
What can we help you with?
How do I find the results of a clinical trial?
What is a clinical study?
How do I know if I'm eligible to join a clinical study?
How do I report errors in ClinicalTrials.gov?
Can I register a study after it has started, has closed to recruitment, or has been completed?
Can I contact a study sponsor?
How do I sign up for a trial on ClinicalTrials.gov?
Where do clinical studies take place?
What else should I think about before deciding to join a study?
How is a clinical study done?
When will the NCT Number for my study be assigned?
How do I contact ClinicalTrials.gov if I have a question about my study record?
How do I find a study I want to join?
What is the definition of a drug, biological, or device product under investigation being "manufactured" in the United States?
How do I know if my clinical trial "Studies a U.S. FDA-regulated Drug Product" or "Studies a U.S. FDA-regulated Device Product" when evaluating whether it is an applicable clinical trial (ACT) subject to the regulation under the conditions specified in 42 CFR 11.22(b)? Specifically, for a trial conducted entirely outside the U.S.?
What happens in a clinical trial?
What is the results information submission deadline for applicable clinical trials (ACTs) of drug, biological, or device products that are not approved, licensed, or cleared for any use and studied in conjunction with, or in comparison to, approved, licensed, or cleared products?
What happens in an observational study?
What are the requirements for updating clinical trial registration information when a Human Subjects Review Board approves a protocol amendment?
Who conducts clinical studies?
To which trials do the potential legal consequences described in 42 CFR 11.66 apply?
How are examinations by telephone call or other electronic means considered in determining when an applicable clinical trial reaches its "primary completion date" or "study completion date" under the regulation?
How long do clinical studies last?
Who can join a clinical study?
How will I be protected if I join a study?
What is an Institutional Review Board?
Do I still see my regular doctors when I'm in a clinical study?
What questions should I ask when trying to decide whether to join a clinical study?
What can I do on the ClinicalTrials.gov web site?
What information can I find on the ClinicalTrials.gov web site?
What kind of web site is ClinicalTrials.gov?
How can my company submit data to ClinicalTrials.gov?
Is there a charge for listing my study on ClinicalTrials.gov?
My study is not yet approved by a human subjects review board (ethics review committee, institutional review board). Can I enter it on ClinicalTrials.gov?
Must clinical studies with no external sources of funding ("unfunded" studies) be registered on ClinicalTrials.gov?
Do I need to register each single-patient investigational new drug application (IND) or protocol exception (including for emergency use) separately?
Can an organization have multiple PRS users for a single account?
To comply with FDAAA 801, must I submit information to ClinicalTrials.gov, or can I use another registry or results database?
Does FDAAA 801 only apply to Industry-sponsored studies?
Does the definition of Applicable Clinical Trial under FDAAA 801 only include studies conducted under an FDA Investigational New Drug Application (IND) or Investigational Device Exemption (IDE)?
Can protocol information be uploaded electronically to ClinicalTrials.gov?
How do I submit results information if the trial is terminated (that is, stopped prematurely) and no data were collected for one or more Outcome Measures?
I completed a clinical trial that studied an investigational product (drug, biological product, or device that is not initially approved, licensed, or cleared by the FDA). There is no intent to seek approval, clearance, or licensure of the product by the FDA (for example, development of the investigational product has been terminated). How do I indicate that results need not be submitted for this trial?
Can an investigator reference a published paper instead of entering all of the results data into ClinicalTrials.gov?
How do I determine if my study is an applicable clinical trial?
If a clinical trial is not an applicable clinical trial (ACT) at study initiation because it is conducted entirely outside the United States, but the trial subsequently opens a U.S. site, am I required to register the trial?
If my study is an applicable clinical trial (ACT), am I required to register?
What registration information must I submit if my applicable clinical trial is required to be registered?
When must I submit the required clinical trial registration information?
Am I required to submit results information for my applicable clinical trial (ACT)?
When is required clinical trial results information due?
Who should submit an Expanded Access record?
What is the final rule's effective date and compliance date?
Can I join a clinical trial if I live outside the United States?
Will my health insurance cover costs if I join a clinical trial?
How often are studies updated in ClinicalTrials.gov?
How do I find information on expanded access studies in ClinicalTrials.gov?
Can I participate in a clinical trial?