Phase I, II, III, IV

Clinical trials for new treatments typically proceed in four phases. Phase I tests safety and dosage in a small group of healthy volunteers. Phase II evaluates effectiveness and further safety in a larger group with the condition. Phase III compares the new treatment to existing options in a large population, confirming its benefits and monitoring side effects. After approval, Phase IV involves post-marketing studies to track long-term safety and effectiveness in the general population. Together, these phases ensure a treatment is safe, effective, and beneficial before widespread use.