Can You Overdose on Marijuana?

woman's hand holding a joint

Barbara Peacock / The Image Bank / Getty Images

Marijuana (cannabis) has a reputation for being a totally benign drug. To read the claims from the proponents of weed, it would seem that cannabis only has beneficial effects. Ask any stoner from the 60s about his or her bad experiences and it becomes clear that marijuana isn't always rainbows and unicorns.

There is plenty of evidence that, as drugs go, marijuana is significantly less dangerous than many other oft-abused substances, including alcohol. But less dangerous is a far cry from saying it's completely safe.

Marijuana Overdose

Marijuana doesn't come with a clear definition of overdose. In fact, doctors aren't entirely sure how much tetrahydrocannabinol (THC) it takes to overdose. THC is the active ingredient in marijuana most likely to induce the high users are seeking.

Risk of Death

Some wonder if marijuana overdose can cause death. There have been a few isolated case reports where marijuana has been implicated in people's death. However, a clear causal relationship has not been established.

What medical professionals aren't clear about, is whether those cases had other contributing factors (like pre-existing cardiac conditions).

Other Adverse Effects

Marijuana is a strange drug in that it contains a lot of active ingredients. Although scientists cite different numbers, in addition to THC, there are thought to be over 100 other cannabinoids in cannabis. Not all of these act the same way.

Get too much THC and you may have a psychoactive reaction that is not unlike that of a stimulant. Cannabidiol (CBD) is associated more with sedative effects. 

The effects of marijuana use are all over the map. There have been cases of heart arrhythmias and sudden cardiac arrest while smoking weed. There are reports of both seizures and the reduction of seizures, which seems to be based on which type of cannabinoid and at what amounts are used.

Here are some examples of THC toxicity that have been published:

  • Heart arrhythmias: Some doctors believe that heart disturbances are under-reported in marijuana use.﻿﻿ Since smoking weed and taking other drugs often go together, it's really hard to isolate the cause when the heart starts doing crazy things. Even drinking alcohol intensifies the effects, which means you can't say for sure whether it was the pot or the booze that caused a problem.
  • Psychosis or paranoia: Users report severe psychotic episodes with hallucinations and negative associations.﻿﻿ In some cases, the psychosis can last significantly longer than the amount of time it should take to metabolize the THC.
  • Uncontrollable vomiting: Although THC often has anti-nausea properties, it can rarely be associated with a syndrome of persistent vomiting. More often associated with chronic cannabis use, uncontrollable vomiting is sometimes relieved with a hot shower.﻿﻿

Edible Overdose

Even the method of consumption makes a difference. For example, a user may consume too much THC in edible form because it takes longer to see an effect. If one brownie doesn't work, they take another...and maybe just one more. Suddenly, they have a serious reaction.

THC that is consumed in edible form is metabolized differently than when it's inhaled.﻿﻿ It takes longer to absorb THC in edibles, which can lead to the user thinking they didn't get enough.

Edibles are also much more prone to accidental overdoses. Smoking marijuana doesn't usually happen accidentally. Even second-hand smoke from your neighbor's party isn't really going to do anything but stink up your apartment.

However, leaving laced cookies lying around pretty much begs for someone to try a bite. Kids are especially likely to munch on marijuana goodies. When grandma is trying a little medical marijuana for the first time and accidentally leaves it out for the grandkids to explore, you have a recipe for overdose.

Children presenting to the emergency department with accidental ingestion of marijuana becomes increasingly common in every state that legalizes marijuana for recreational use. Once it's legal and tolerated, it's a lot easier to accidentally leave your marijuana out on the coffee table for the kids to find.

Increased Concerns About Overdose

There are several reasons that medical and health experts have become concerned about the potential for marijuana overdose and adverse effects.

Increased Marijuana Use

Marijuana has been available for medicinal use since 1996 when California legalized it. Now, California, Alaska, Colorado, Maine, Massachusetts, Michigan, Nevada, Vermont, Washington, and Washington D.C. allow recreational use. In Oregon, the number of dispensaries doubled after recreational weed was legalized.

As the momentum of recreational pot burns across the country, people you probably didn't expect to see getting high are trying weed for the first time in years. While they might have smoked a little pot in college, this isn't the same thing.

Many in the medical world report being a bit surprised by the marked increase in marijuana use in states where it has been legalized. Many paramedics, EMTs, and emergency department healthcare providers figured that those who cared about getting high had their medical marijuana prescriptions and could get it when they wanted.

As it turned out, there were plenty of people interested in trying the recently illicit substance. All that new consumption has led to significant increases in marijuana-induced emergency department visits.

Increased THC Concentration

Just like how modern farmers are able to get much bigger yields from crops like corn and beans, weed farmers today are much more successful than they were in the past. The levels of THC in marijuana are well above what it was before the current farmers were born.

The concentrations of THC increased from 3.4% in 1993 to 8.8% in 2008.﻿﻿ Some folks say that just means you don't have to roll the blunts as fat as you used to, but let's face it: When you're chasing the high, the bar just keeps getting higher.

A Word From Verywell

Marijuana overdose is still a debated topic and there isn't really a clear answer on how much pot is too much. Until there is, it's important to be diligent if you choose to use and to keep yourself informed. Don't accept the mantra that weed is natural and therefore, safe. What makes anything safe is an informed consumer and a critical mind.

Was this page helpful?
Article Sources
  1. Orsini, J., Blaak, C., Rajayer, S., Gurung, V., Tam, E., & Morante, J. et al. Prolonged cardiac arrest complicating a massive ST-segment elevation myocardial infarction associated with marijuana consumptionJournal Of Community Hospital Internal Medicine Perspectives. 2016;6(4):31695. doi:10.3402/jchimp.v6.31695

  2. Greydanus, D., Hawver, E., Greydanus, M., & Merrick, J. Marijuana: current conceptsFrontiers In Public Health. 2013;1. doi:10.3389/fpubh.2013.00042

  3. Fitzgerald KT, Bronstein AC, Newquist KL. Marijuana poisoning. Top Companion Anim Med. 2013;28(1):8-12. doi:10.1053/j.tcam.2013.03.004

  4. Mehmedic Z, Chandra S, Slade D, Denham H, Foster S, Patel AS, Ross SA, Khan IA, ElSohly MA. Potency trends of Δ9-THC and other cannabinoids in confiscated cannabis preparations from 1993 to 2008. J Forensic Sci. 2010;55(5):1209-17. doi:10.1111/j.1556-4029.2010.01441.x