As of January 2017, 29 states have legalized medical marijuana. However, marijuana remains a Schedule l substance under the Controlled Substances Act. Substances in Schedule l are determined by the Food and Drug Administration (FDA) to have no medical use, and states that allow the use of marijuana for medical use violate federal law.

Although the use of marijuana for medicinal purposes is often touted as one reason for the legalization of marijuana, little is known about the long-term impact of the use of medical marijuana particularly on people with health- and/or age-related vulnerabilities – such as individuals suffering from cancer, AIDS, cardiovascular disease, multiple sclerosis, or other neurodegenerative diseases.

(See https://www.drugabuse.gov/publications/marijuana/marijuana-safe-effective-medicine) Further research is needed to determine whether people whose health has been compromised by disease or its treatment (e.g., chemotherapy) are at greater risk for adverse health outcomes from marijuana use.
The FDA believes that scientifically valid research conducted under an investigational new drug (IND) application is the best way to determine which patients could benefit from the use of drugs derived from marijuana. According to the FDA’s website, the FDA supports the conduct of that research by:
  1. Providing information on the process needed to conduct clinical research using marijuana;
  2. Providing information on the specific requirements needed to develop a drug that is derived from a plant such as marijuana. In June 2004, the FDA finalized its Guidance for Industry: Botanical Drug Products, which provides sponsors with guidance on submitting IND applications for botanical drug products;
  3. Providing specific support for investigators interested in conducting clinical research using marijuana and its constituents as a part of the IND process through meetings and regular interactions throughout the drug development process;
  4. Providing general support to investigators to help them understand and follow the procedures to conduct clinical research through the FDA Center for Drug Evaluation and Research’s Small Business and Industry Assistance group.
The FDA reviews applications to market drug products to determine whether those drug products are safe and effective for their intended indications. The FDA reviews scientific investigations, including adequate and well-controlled clinical trials, as part of the FDA’s drug approval process and relies on applicants and scientific investigators to conduct research. However, marijuana’s status as a Schedule l drug under the Controlled Substances Act means conducting clinical research using marijuana involves interactions with several federal agencies. These include: a registration administered by the Drug Enforcement Administration (DEA); obtaining the marijuana for research from the National Institute on Drug Abuse (NIDA), within the National Institutes of Health, or another DEA-registered source; and review by the FDA of an IND application and research protocol. According to the FDA:
  • As a Schedule I controlled substance under the Controlled Substances Act, DEA provides researchers with investigator and protocol registrations and has Schedule I-level security requirements at the site marijuana will be studied.
  • NIDA provides research-grade marijuana for scientific study. The agency is responsible for overseeing the cultivation of marijuana for medical research and has contracted with the University of Mississippi to grow marijuana for research at a secure facility. Marijuana of varying potencies and compositions is available. DEA also may allow additional growers to register with the DEA to produce and distribute marijuana for research purposes.
  • Researchers work with the FDA and submit an IND application to the appropriate division in the Office of New Drugs, in the Center for Drug Evaluation and Research (CDER), depending on the therapeutic indication.
The FDA has approved Marinol and Syndros, which include the active ingredient dronabinol, a synthetic delta-9- tetrahydrocannabinol (THC), for therapeutic uses in the United States, including for the treatment of anorexia associated with weight loss in AIDS patients. Another FDA-approved drug, Cesamet, contains the active ingredient nabilone, which has a chemical structure similar to THC and is synthetically derived.

To date, the FDA has not approved a marketing application for marijuana for any indication.

The FDA generally evaluates research conducted by manufacturers and other scientific investigators. Its role, as laid out in the Federal Food, Drug, and Cosmetic (FD&C) Act, is to review data submitted to the FDA in an application for approval to assure that the drug product meets the statutory standards for approval.