Certified Clinical Research Associate (CCRA) Practice Exam 2026 – Complete Preparation Guide

An Investigational Drug is specifically defined as a drug that is being tested in or used as a reference in a clinical trial. This encompasses medications that have not yet received marketing approval but are under investigation to evaluate their efficacy and safety for potential future use in patients. Clinical trials are essential for ensuring that a drug is both safe and effective before it can be made available to the public.

In contrast, other options describe drugs in different contexts. A drug approved for market use is not investigational because it has already passed through clinical trials and received the necessary approvals for general use. A controlled substance for research purposes refers to specific classes of drugs that may be used in various research contexts, but this does not encompass all investigational drugs; not all investigational drugs are controlled substances. Lastly, a medication used only for in vitro diagnostics pertains to tests done outside the body (in a controlled environment, like a lab) and does not fall under the category of investigational drugs meant for human use in clinical trials.