Placebo is best described as which of the following?

• A. Placebo
• B. Double-Blind Study
• C. Crossover Study
• D. New Drug Application (NDA)

Answer: (A)

A placebo is an inert substance or sham treatment used as a control in clinical trials. It has no therapeutic effect on its own, but it helps determine the true effect of the active drug by providing a baseline for comparison. Using a placebo also supports blinding, reducing bias from participants’ and researchers’ expectations. The other terms describe study designs or regulatory steps rather than what a placebo is: a double-blind study refers to hiding treatment assignment to reduce bias, a crossover study involves giving different treatments to the same participants in sequence, and a New Drug Application is the regulatory filing to approve a drug. Therefore, the best description of placebo is an inert comparison substance used as the control in trials.