Each ClinicalTrials.gov record presents summary information about a study protocol and includes the following:

• Disease or condition
• Intervention (for example, the medical product, behavior, or procedure being studied)
• Title, description, and design of the study
• Requirements for participation (eligibility criteria)
• Locations where the study is being conducted
• Contact information for the study locations
• Links to relevant information on other health Web sites, such as NLM's MedlinePlus® for patient health information and PubMed® for citations and abstracts of scholarly articles in the field of medicine

Some records also include information on the results of the study, such as:

• Description of study participants (the number of participants starting and completing the study and their demographic data)
• Outcomes of the study
• Summary of adverse events experienced by study participants

The full history of the changes made to a record can be accessed by viewing the archival version of the record on the ClinicalTrials.gov archive. Once a study is registered on the site, the information about it is not removed.