A study where some participants receive an inactive treatment—the gold standard for proving a drug actually works beyond the placebo effect.Placebo-controlled trials compare an active treatment against an inert control, isolating the treatment’s pharmacological effect from placebo response, natural disease course, and regression to the mean. For peptide research, placebo control is especially important because injection-based delivery can produce substantial placebo responses in subjective endpoints. A compound with only open-label data has not demonstrated efficacy above placebo—this distinction is critical for honest evidence evaluation.