Placebos play a central role in clinical trials by helping separate the true biological effect of a treatment from improvements driven by expectation or context. The ethics around their use are still debated, but there’s broad agreement that placebos are appropriate when no proven therapy exists, when withholding treatment poses little risk, or when strong methodological reasons justify their use. Evidence from pain studies shows that placebo responses are common—usually modest, but sometimes meaningful. Importantly, deception isn’t required: open-label placebos, where patients know they’re receiving a placebo, can still reduce symptoms. While placebos aren’t meant to replace active treatments, they can enhance outcomes when clinicians intentionally shape positive expectations through communication, clear explanations, and supportive therapeutic environments.