Toxicity is virtually nonexistent in natural marijuana. The toxicity levels of cannabis compounds are estimated at 40,000, meaning that a subject would have to ingest 40,000 times the regular dose to induce death. “In layman’s terms,” according to The New England Journal of Medicine, ”a smoker would theoretically have to consume nearly 1,500 pounds of marijuana within about fifteen minutes to induce a lethal response.” [1] While that amount of consumption is certainly an impossible feat, in comparison, legal prescription medications cause thousands of deaths per year. [2] Common household drugs are much more lethal than marijuana. For instance, a lethal dose of caffeine is equal to about 100 cups of coffee. [3]  In 1972, after reviewing the scientific evidence, the National Commission on Marijuana and Drug Abuse concluded that while marijuana was not entirely safe, its dangers had been grossly overstated. [4] Since then, researchers have conducted thousands of studies on humans, animals and cell cultures. None of those describe any findings dramatically different from those described by the National Commission in 1972. [5] In 2008, The Canadian Medical Association Journal published a review of research spanning 30 years, concluding that there are no serious adverse effects of cannabis use.[6]  Contaminants, however, are known to be hazardous, especially to those suffering from immune disorders. [7]

Related sections: Contaminants, Immune Responses, Replacement of Medications.



[1] Annas, “Reefer Madness—The federal response to California’s medical-marijuana law.” The New England Journal of Medicine, Vol. 337, No. 6, August 7, 1997

[2] “Death from drug errors rise sharply for outpatients.” The Seattle Times, Febraury 28, 1998

[3] American Psychiatric Association, Desk Reference to the Diagnostic Criteria from DSM-3-R

[4] National Commission on Marijuana and Drug Abuse, 1972

[5] Buckley, “Is marijuana fear a myth?” National Review, August 24, 1997

[6] “The adverse effects of cannabinoids: implications for use of medical marijuana” Louisa Degenhardt, MPsych(Clin) PhD and Wayne D. Hall, PhD CMAJ • June 17, 2008; 178 (13). doi:10.1503/cmaj.080585.© 2008 Canadian Medical Association or its licensors

[7] Hollister, “Health aspects of marijuana.” Pharmacological Review, Vol. 38, No. 1, 1986