A clinical trial is a test to measure the effectiveness and/or safety of a new product or medical procedure. In the case of a product, a clinical trial is conducted in order to gather data to support approval by an appropriate government agency such as the US Food and Drug Administration (FDA).

Clinical trials must follow an approved protocol, or standard method of testing that covers everything from how patients are evaluated before entering the trial, to how the product is used during the trial and how patient results are collected and measured. This is done to reduce as much as possible the potential effects of unrelated factors and determine as accurately as possible if the product is working as it’s designed to work.

Many clinical trials are also “randomized controlled” trials, meaning that patients are randomly assigned to one of two groups, one of which will receive the drug or device being tested while the other group – the “control” group – receives a standard non-experimental treatment, which in some drug trials may be a placebo, often referred to as a “sugar pill.” Treatment data from these two patient groups are then compared as a way to measure the effectiveness of the product being tested. Patients usually do not know which group they have been assigned to in order to avoid the possibility of skewing the results, and this is referred to as “blinding”.