The systematic process of incrementally increasing drug doses during a clinical trial, starting from a low initial dose and advancing to higher doses only after confirming safety at each level. Dose escalation is the defining feature of Phase I clinical trials.

Standard designs include the “3+3” method (three patients per dose level, escalate if no dose-limiting toxicities) and more sophisticated Bayesian approaches. The goal is to identify the maximum tolerated dose (MTD) and the dose-limiting toxicities (DLTs). For peptide therapeutics, dose escalation data provides the most reliable safety information available—but many research peptides have never undergone formal dose escalation studies in humans, making their safety profiles fundamentally uncertain.