In randomized controlled trials, what is the purpose of using a placebo?

• A. The actual treatment being tested
• B. A treatment that looks identical but has no active effect
• C. A different treatment
• D. No treatment

Answer: (B)

In randomized controlled trials, the purpose of using a placebo is to provide an inert comparator that looks identical to the real treatment. This allows participants and researchers to be blinded to who receives the active intervention, reducing bias in reporting and assessment. Because the placebo has no active effect, any differences in outcomes between groups can be attributed to the treatment itself rather than to expectations or the care process. It serves as a baseline that mirrors the experience of receiving treatment without pharmacological action, so the true effect of the active treatment can be isolated.