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.
The FDA mandates a four-step series of clinical trials for drug testing. Phase I examines new drugs on healthy volunteers in small groups to find the highest safe dosage. Phase II tests patients with the condition the drug aims to treat, assessing safety and minimal effectiveness in a slightly larger group.