The FDA requires a four-phased series of clinical trials for testing drugs. Phase I involves testing new drugs on healthy volunteers in small groups to determine the maximum safe dosage. Phase II trials involve patients with the condition the drug is intended to treat to test for safety and minimal efficacy in a somewhat larger group of people.
According to FDA regulations, there are four phases of clinical trials for drug evaluation. In Phase I, new drugs are tested on healthy volunteers in small groups to identify the maximum safe dosage. Phase II involves patients with the condition the drug intends to treat, focusing on safety and minimal efficacy within a larger group.