What are “investigational new drugs” (IND)?

Investigational new drugs (IND) refer specifically to drugs that are still in the research and development phase. These substances are being assessed through clinical trials to determine their safety and efficacy for human use but have not yet received approval from the FDA for general marketing.

This process allows researchers to gather data on the drug's effects, optimal dosages, and side effects before it can be made available to the public. Approval from the FDA is critical, as it ensures that any drug sold to the public has undergone rigorous testing and meets necessary safety and efficacy standards.

The other options describe different categories of drugs. For example, drugs that have been on the market for over a year do not fit the definition of “investigational” since they have already gone through the approval process. Drugs purchasable without a prescription typically refer to over-the-counter medications which have already been deemed safe for consumer use by regulatory authorities. Lastly, drugs for compassionate use pertain to situations where a patient is granted access to an investigational drug outside of a clinical trial—this is a different context from that of INDs, which are still under study.