Medical cannabis is widely known to have an excellent safety profile.
According to the The Drug Awareness Warning Network Annual Report, published by Substance Abuse and Mental Health Services Administration (SAMHSA), there has never been a death recorded from the use of cannabis. The report outlines enormous doses that have been tested. Laboratory animals, small and large, can tolerate doses of up to 1000mg/kg. This would be equivalent to an individual consuming, at one time, their entire body weight in cannabis, which is 5,000 times more than is required to produce the desired effect.
Given the absence of reported deaths, it is only possible to estimate the theoretical lethal dose (LD50) of medical cannabis, which is thought to be between 1:20,000 and 1:40,000.