What is a placebo in trials?

A placebo in clinical trials is a substance or treatment that has no therapeutic effect, often used as a control to compare against the actual treatment being tested. Participants receiving the placebo may experience perceived improvements due to their expectations, known as the placebo effect. This helps researchers determine the efficacy of the active treatment by isolating its effects from psychological influences. Placebo-controlled trials are essential for validating the effectiveness of new medications or therapies.