All potential pharmaceutical compounds begin in with a pre-clinical trial. Here, investigators learn as much as they can in the lab and by using animal testing. Preclinical research can last one to three years, with an average of about 18 months. If the results are promising enough, the researchers will file an Investigational New Drug Application (IND) with the Food and Drug Administration for permission to begin testing in humans. A response will generally come from the FDA within 30 days.