Which of the following phases generally involved a few healthy individuals, and is designed to determine the safety of a drug?

• A. Phase I
• B. Phase II
• C. Phase III
• D. Phase IV

Answer: (A)

The key idea is testing safety in people at the very start of human trials. In this early stage, a small group of healthy volunteers is given the drug to see how it behaves in the body, identify any side effects, and determine safe dosing ranges. Researchers look at tolerability and pharmacokinetics (how the body absorbs, distributes, metabolizes, and excretes the drug) to establish a safe starting point for later testing. If a drug can’t be given safely to healthy people, this stage may involve patients with the condition instead, but the core goal remains safety and dosage guidance for future studies. In later stages, trials expand to patients to assess whether the drug actually works and to continue monitoring safety in larger groups.