"Under the current contract with the University of Mississippi for any given year NIDA [National Institute on Drug Abuse] has the option to grow either 1.5 or 6.5 acres of cannabis, or to not grow any at all, depending on research demand. Generally, 1.5 acres are grown in alternate years. The number of cannabis cigarettes produced from 1.5 acres is about 50,000-60,000, although it can be higher. Cigarettes are produced in three potencies: strength 1 - 3-4 %; strength 2 - 1.8-2.2 %; and strength 3 - placebo, as close to 0% as possible. During the past three years, the following quantities have been shipped: 1994 - 24,000 cigarettes; 1995 - 23, 100 - cigarettes; and 1996 17,700 cigarettes. Virtually all of the cigarettes shipped in the last three years have been for single patient INDs. As of March 1997 there were 278, 100 cigarettes in stock. The cigarettes are maintained in frozen storage and have a useful life of approximately five years."

Source

"Provision of Marijuana and Other Compounds For Scientific Research - Recommendations of The National Institute on Drug Abuse National Advisory Council," National Institute on Drug Abuse (Bethesda, MD: Department of Health and Human Services, National Institutes of Health, January 1998).
http://archives.drugabuse.gov...