Protocol

The detailed written plan for a clinical trial — who can join, exactly what happens, and how results are measured.

Think of the protocol as the trial’s rulebook. Before a single person joins, researchers write down exactly how the study will run: who is eligible, what treatment or tests each person receives, on what schedule, what information gets collected, and how they’ll judge whether it worked.

The protocol matters to you for a simple reason: it means nothing is improvised. Everyone in the trial is treated according to the same careful plan, and that plan is reviewed by an independent ethics board before the trial can open. If you join a trial, you’re entitled to understand the parts of the protocol that affect you — and to ask questions until they make sense.