Clinical trials are typically divided into four phases: 1. Phase I: This phase focuses on the safety of the substance. It involves a small group of healthy volunteers or patients and aims to identify side effects and safe dosage ranges. 2. Phase II: This phase involves a larger group of individuals to evaluate the efficacy and further assess safety. 3. Phase III: These trials involve even larger groups to confirm effectiveness, monitor side effects, and compare the new treatment to commonly used treatments. 4. Phase IV: Conducted after the substance has been approved for market use, these trials gather additional information on the drug's risks, benefits, and optimal use.
