While prescription painkillers cause thousands of overdose deaths each year, no one has ever died from a marijuana overdose.
In fact, studies suggest it is impossible to die from smoking too much marijuana. But indirect deaths are possible — and documented.
Of course, what some people mean when they say “overdose” is simply taking too much of a drug. When using this definition, it’s certainly possible to overdose on marijuana, which can lead to unpleasant symptoms like anxiety, dizziness, and vomiting.
Let’s take a look at what science says about overdosing on marijuana.
The short answer is no. According to the National Cancer Institute, you cannot die of a marijuana overdose. Here’s why:
“Because cannabinoid receptors, unlike opioid receptors, are not located in the brainstem areas controlling respiration, lethal overdoses from Cannabis and cannabinoids do not occur.”
In other words, marijuana and opioids affect different pathways of the body. Opioid pathways, also known as receptors, are present in areas of the brain that control breathing. As a result, taking too many painkillers can cause a person to stop breathing.
But marijuana acts on a completely different set of pathways. These pathways are called cannabinoid receptors and they do not affect respiration. Thus, marijuana cannot cause someone to stop breathing, no matter how much they ingest.
While it’s essentially impossible to consume enough THC to kill you, you may be able to die as an indirect consequence of taking marijuana. So the long answer is possibly, indirectly.
There have only been a small number of reported cases of THC-induced deaths, and none was directly caused by overdose.
In a 2014 incident, an inexperienced user overdosed on an edible marijuana product. He became agitated and confused, and jumped to his death from a balcony. This was an indirect effect of severe intoxication, but it wasn’t death by THC overdose.
In another case, a person passed out and hit their head after doing a dab — a strong hit of cannabis concentrates.
Dabs are potent cannabis extracts that have especially high concentrations of THC. While dried marijuana typically contains 10-20% THC, dabs contain 70-90% THC.
Dabbing delivers a super strong hit of THC, and it’s known for getting even seasoned smokers high. That being said, concentrates are just THC and you cannot overdose on THC.
The lethal dose of marijuana is thought to be extremely high. While lethal doses have not been observed in humans, they can be estimated by injecting rats with large doses of THC.
Scientists use a measure called the LD50 (lethal dose) to describe the dose of a drug that would kill 50% of a given population. Another measure called the ED50 (effective dose) refers to the dose of a drug that works for 50% of the population.
In general, the closer the LD50 and the ED50 are, the more dangerous the drug is.
For example, the LD50 for alcohol is 10 drinks (a drink meaning 1 shot, beer, or glass of wine) all at once. Compared to the effective dose, which is simply 1 drink, it’s easy to see why alcohol poisoning is so common. And when it comes to heroin, the lethal dose is only 5 times the effective dose.
The lethal dose for marijuana is estimated to be 40,000 times the effective dose. In other words, someone would have to take 40,000 times the normal amount of marijuana in order to die. This explains why overdosing on marijuana is basically unheard of.
While it’s impossible to die from a marijuana overdose, taking too much of the drug can lead to unpleasant symptoms.
This phenomenon is commonly referred to as “greening out”, or what doctors call acute THC toxicity.
Symptoms of marijuana overdose include:
Emergency room visits due to overdose are on the rise in areas where marijuana has been legalized. In most cases, these incidents involve inexperienced users, and people trying edibles for the first time.
It’s easier to green out from an edible for a few reasons. When someone smokes marijuana, the psychoactive effects show up almost immediately. But when taken orally, it can take 1-3 hours before the user notices the effects.
Inexperienced users may believe the edible isn’t working, and consume excess amounts. Once the effects take hold, the result is an overpowering high.
Another concern is accidental consumption. It’s very important to clearly label any marijuana edibles so children or unwitting adults don’t mistakenly consume them.
Symptoms resulting from an overdose of THC usually last for a short duration, but severe cases of overdose can last for several days.
If you or someone you know is experiencing symptoms of a marijuana overdose, don’t panic. A marijuana overdose is only temporary, and symptoms will eventually subside.
Here are a few steps you can take to help the person feel more comfortable and to keep them safe.
Marijuana does not pose a risk of lethal overdose. In other words, you can’t die from smoking too much weed.
Regardless, it’s certainly possible for users to consume too much marijuana at once. This is called overdosing or “greening out”.
Greening out is most likely among inexperienced users, or those who consume edibles. However, the effects are not permanent and symptoms eventually subside.
If you or a friend has consumed too much marijuana, keep hydrated, stay with people you know, and seek medical attention if things worsen.