A clinical trial or study protocol is essentially a self-contained document or booklet of rules that outline in detail what the trial hopes to accomplish, how the trial will be carried out, and how the progress of the treatment program will be assessed, how the final data will be analysed. The protocol is developed from extensive consideration of how best to conduct the study from both a clinical and statistical point of view. The success of any project depends greatly on this stage of development of protocol which generally takes several weeks or months.

The medical writers design the protocol in coordination with physicians (or dentists), medical personnel from the sponsor company (in case the protocol is asked to be written by a CRO), representatives from the study monitoring, safety monitoring, data management, quality assurance, statistics and drug logistics team.