The Food and Drug Administration's (FDA) New Drug Application (NDA) is the vehicle in the United States through which drug sponsors formally propose that the FDA approve a new pharmaceutical for sale and marketing. Some 30% or less of initial drug candidates proceed through the entire multi-year process of drug development, concluding with an approved NDA, if successful. The goals of the NDA are to provide enough information to permit FDA reviewers to establish the complete history of the candidate drug. Among facts needed for the application are: Patent and manufacturing information Drug safety and specific effectiveness for its proposed use(s) when used as directed Reports on the design, compliance, and conclusions of completed clinical trials by the Institutional Review Board Drug susceptibility to abuse Proposed labeling (package insert) and directions for use Exceptions to this process include voter driven initiatives for medical marijuana in certain states. Before trials To legally test the drug on human subjects in the U.S., the maker must first obtain an Investigational New Drug (IND) designation from FDA. This application is based on nonclinical data, typically from a combination of in vivo and in vitro laboratory safety studies, that shows the drug is safe enough to test in humans. Often the "new" drugs that are submitted for approval include new molecular entities or old medications that have been chemically modified to elicit differential pharmacological effects or reduced side effects. Clinical trials The legal requirement for approval is "substantial" evidence of effectiveness demonstrated through controlled clinical trials. This standard lies at the heart of the regulatory program for drugs. Data for the submission must come from rigorous clinical trials. The trials are typically conducted in three phases: Phase 1: The drug is tested in 20 to 100 healthy volunteers to determine its safety at low doses. About 70% of candidate drugs advance to Phase 2. Phase 2: The drug is tested for both efficacy and safety in up to several hundred people with the targeted disease. Some two-thirds of candidate drugs fail in Phase 2 clinical trials due to the drug not being as effective as anticipated. Phase 3: The drug is typically tested in several hundred to several thousand people with the targeted disease in double-blind, placebo controlled trials to demonstrate its specific efficacy. Under 30% of drug candidates succeed through Phase 3. Phase 4: These are postmarketing surveillance trials in several thousand people taking