Which statement best describes an investigational drug?

• A. Has been tested in a lab and approved by the FDA to be tested in humans
• B. An approved drug undergoing further investigation for new indications
• C. A new chemical or compound that has not been approved by the FDA for general use
• D. A drug that is not subject to FDA oversight during clinical trials

Answer: (C)

An investigational drug is a new chemical or biological substance that has not yet received FDA approval for general use and is being studied in humans under regulatory oversight. This description matches the statement that a brand-new compound has not been approved by the FDA for general use. It captures the idea that the drug is still in development and data on safety and efficacy are being collected before any potential approval for widespread use.

Other scenarios aren’t investigational in the same sense: an approved drug being explored for new indications has already cleared FDA use for its current indications, so it isn’t investigational for the purpose of testing a wholly new product. And a drug not subject to FDA oversight during trials would contradict the regulatory framework that governs human testing of new therapies.