Can You Overdose on Marijuana?

Though life-threatening marijuana overdoses may be unlikely, dose-dependent toxicity is quite possible; individuals who consume enough of the primary psychoactive component in marijuana and other cannabis-derived products are at risk of experiencing a range of unpleasant effects.1,2 Additionally, marijuana use can place people in danger of accidental death and injury (from automobile accidents, for example).2

The National Institute on Drug Abuse (NIDA) indicates that, in the United States, marijuana is used more commonly than any other psychotropic drug with the exception of alcohol.3 Results of the National Survey on Drug Use and Health from 2018  estimate that more than 123 million individuals 12 years old or older in the U.S. had used marijuana in their lives, and that more than 27 million had in the past month.4

This same survey data indicate that marijuana was used in the last year by:4

  • Over 12% of individuals 12 through 17 years old.
  • Over 34% of individuals 18 through 25 years old.
  • Over 19% of individuals 26 through 49 years old.
  • Over 7% of individuals 50 years old or older.

Potential Risks of Marijuana Use

The speed of onset and magnitude of marijuana intoxication is related to the quantity of intake (i.e., dose) as well as the route of administration used (e.g., inhaling smoke or vapor, consuming edible products). Smoking marijuana, for example, allows for nearly instantly perceptible intoxicating effects.5,6

The onset of the marijuana high may be somewhat delayed when the drug is consumed orally, such as via food or drink. In such instances,  an individual might expect to first feel the effects of the drug as long as 30 to 60 minutes after ingestion. Noticeable impacts of marijuana when it’s smoked typically persist for 1-3 hours; when it’s ingested via food or drink, the drug effects might persist for several additional hours.5

As a result of a physiological phenomenon known as first-pass metabolism, oral consumption of cannabis products can be expected to result in a lower blood concentration than an identical dose of the active chemical component—tetrahydrocannabinol, or THC—should it be smoked.5 However, because of the inherent delay in onset of the drug effects, people who use edible cannabis products may ultimately be at increased risk of inadvertently consuming more THC than intended, as they may consume increasing amounts waiting for the high to kick in.2,5 Such difficulties in gauging an “effective” dose with edible products are likely to play a role in many cannabis-related emergency room visits.2

Regardless of the route of ingestion, marijuana’s effects may include:5,6,7

About The Contributor

Scot Thomas, M.D.
Scot Thomas, M.D.

Senior Medical Editor, American Addiction Centers

Dr. Thomas received his medical degree from the University of California, San Diego School of Medicine. During his medical studies, Dr. Thomas saw firsthand the multitude of lives impacted by struggles with substance abuse and addiction, motivating... Read More

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