Compassionate Use is a term used by most patients and doctors for the legal practice of using a drug that is still in clinical trial but not FDA approved for general use. The FDA prefers the term expanded access to experimental drugs through a process called Treatment Investigational New Drug Application or Treatment IND.

There are several rules for early access programs. First, the drug company must be willing to sponsor such a program. Second, the participant must not be eligible to participate in a clinical trial. And third, the drug must be either in phase III clinical trial or going through FDA regulatory phases. Though compassionate use programs are labor-intensive, Alzheimer's, Parkinson's and Multiple Sclerosis patients have used this type of program to obtain drugs prior to FDA approval.