A clinical research study is also called a clinical trial. Each study tests the safety, effectiveness, and side effects of an investigational medicine or an investigational device on a group of volunteers. Clinical research studies are an important step in making new investigational medications available for future use.

The U.S Food & Drug Administration (FDA) typically must authorize a drug company’s proposal to conduct clinical studies. Drug companies must do years of research before they can begin medicines in humans.

Preclinical (animal) testing.
An investigational new drug application (IND) outlines what the sponsor of a new drug proposes for human testing in clinical trials.
Phase 1 studies (typically involve 20 to 80 people).
Phase 2 studies (typically involve a few dozen to about 300 people).
Phase 3 studies (typically involve several hundred to about 3,000 people).
The pre-NDA period, just before a new drug application (NDA) is submitted. A common time for the FDA and drug sponsors to meet.
Submission of an NDA is the formal step asking the FDA to consider a drug for marketing approval.
After an NDA is received, the FDA has 60 days to decide whether to file it so it can be reviewed.
If the FDA files the NDA, an FDA review team is assigned to evaluate the sponsor’s research on the drug’s safety and effectiveness.
The FDA reviews information that goes on a drug's professional labeling (information on how to use the drug).
The FDA inspects the facilities where the drug will be manufactured as part of the approval process.
FDA reviewers will approve the application or find it either “approvable” or “not approvable.”
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