How many phases of testing in humans does the FDA require?

The FDA requires three phases of clinical testing in humans before a new drug can be approved for public use.

Phase 1 is primarily focused on safety, involving a small number of healthy volunteers to evaluate the drug's pharmacokinetics and pharmacodynamics, as well as identifying any potential side effects.

Phase 2 further assesses safety but shifts focus to evaluating the drug's efficacy in a larger group of individuals who have the condition the drug intends to treat. This phase helps to establish the optimal dosages and further investigates side effects.

Phase 3 involves an even larger sample size and aims to confirm the effectiveness of the drug, monitor side effects, and compare the new drug to commonly used treatments. Successful completion of all three phases is essential for the FDA to determine whether a drug is safe and effective for public distribution.

The options indicating fewer or more phases do not align with the established regulatory framework set by the FDA. Hence, the three-phase requirement is crucial for ensuring that any new drug has undergone extensive testing to protect public health.