An investigational product is a pharmaceutical form of an active ingredient or placebo

Placebo

A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...

 being tested or used as a reference in a clinical trial

Clinical trial

Clinical trials are a set of procedures in medical research and drug development that are conducted to allow safety and efficacy data to be collected for health interventions...

, including a product with a marketing authorization when used or assembled (formulated or packaged) in a way different from the approved form, or when used for an unapproved indication, or when used to gain further information about an approved use. This has been referred to by the National Center for Policy Analysis

National Center for Policy Analysis

The National Center for Policy Analysis is a non-profit American conservative think tank whose goals are to develop and promote private alternatives to government regulation and control...

 as open access to such drugs.

See also

• Drug
  Drug
  A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...
  
  
• Drug development
  Drug development
  Drug development is a blanket term used to define the process of bringing a new drug to the market once a lead compound has been identified through the process of drug discovery...
  
  
• U.S. Food and Drug Administration (FDA)
• European Medicines Agency
  European Medicines Agency
  The European Medicines Agency is a European agency for the evaluation of medicinal products. From 1995 to 2004, the European Medicines Agency was known as European Agency for the Evaluation of Medicinal Products.Roughly parallel to the U.S...