There are alot of rules around how to run clinical trials, based on international guidelines and local country regulations. The International guidance for how clinical trials are run is known as Good Clinical Practice (ICH-GCP). These guidelines set out the responsibilities of ethics committees, researchers, sponsors and monitors of trials, the records that should be kept and the details around documentation like safety information, study protocols and the information given to volunteers.
All trials that carry any type of risk will be reviewed and approved by a Research Ethics Committee /Institutional Review Board before they start. In some countries, the regulatory authority may also need to provide some type of approval before clinical trials can start.