Marijuana is roughly 114 times less deadly than alcohol, according to recent findings published in the journal Scientific Reports. Of the seven drugs included in the study, alcohol was the deadliest at an individual level, followed by heroin, cocaine, tobacco, ecstasy, methamphetamines, and marijuana. Previous studies consistently ranked marijuana as the safest recreational drug, but it was not known that the discrepancy was this large.
The researchers determined the mortality risk by comparing a lethal dose of each substance with the amount typically used. Not only was marijuana the lowest of the drugs tested, but there was such a gap between its lethal and typical doses that they classified it as the only "low mortality risk" drug tested. All others were classified as "medium" or "high."
Marijuana comes with a low mortality risk compared to drugs like ecstasy or tobacco
These findings contradict the efforts of law enforcement agencies around the country which, despite pockets of decriminalization (and in some cases, legalization), typically focus heavily on marijuana-related arrests. The authors suggest that, based on the results, these agencies would benefit from shifting priorities away from illicit drugs and placing them instead on keeping things like alcohol and tobacco in check. In fact, the researchers believe marijuana to be so low-risk that they suggest a broad, regulated legalization of it in the paper.
Attempts to compare the danger of particular drugs have been few and far between. It wasn't until the last decade that studies were done to classify the risk of drug abuse in a qualitative and quantitative manner, according to the authors. (They cite attempts at indexing the toxicity or ranking the harm of certain drugs as examples.) Before that, they claim, the risk assessment of drug abuse was instead based heavily on anecdotal evidence, which often meant that policy decisions were largely based on educated guesses.
The researchers clarified that the study does not suggest that moderate alcohol consumption poses a higher risk than regular heroin use. Environmental conditions, like dirty needles or unregulated supplies, contribute to the overall harm caused by using a drug like heroin. Instead, this study was specifically done to measure the deadliness of the substances themselves.