Can You Overdose on Marijuana?
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.
Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.
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 their 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 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.
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.
Learn about the risks of using too much marijuana, and find out whether it's possible to overdose from it and die.
How Pot Affects Your Mind and Body
In this Article
In this Article
In this Article
- You Can Get “High”
- It May Affect Your Mental Health
- Your Thinking May Get Distorted
- You May Get Hooked
- It May Impair Your Brain
- Your Lungs May Hurt
- It May Ease Your Pain and Other Symptoms
- You May Feel Hungrier
- It May Harm Your Heart
- It Intensifies Alcohol’s Dangers
- Your Newborn Might Be Underweight
- Connection to Cancer Is Unclear
- What’s CBD?
- Ways to Use Marijuana
Marijuana, weed, pot, dope, grass. They’re different names for the same drug that comes from the cannabis plant. You can smoke it, vape it, drink it, or eat it. Most folks use marijuana for pleasure and recreation. But a growing number of doctors prescribe it for specific medical conditions and symptoms.
Marijuana has mind-altering compounds that affect both your brain and body. It can be addictive, and it may be harmful to some people’s health. Here’s what can happen when you use marijuana:
American Cancer Society: “Marijuana and Cancer.”; Mayo Clinic: “Medical marijuana,” “Is medical marijuana legal?”; American Lung Association: “Marijuana and Lung Health.”
You Can Get “High”
It’s why most people try pot. The main psychoactive ingredient, THC, stimulates the part of your brain that responds to pleasure, like food and sex. That unleashes a chemical called dopamine, which gives you a euphoric, relaxed feeling.
If you vape or smoke weed, the THC could get into your bloodstream quickly enough for you to get your high in seconds or minutes. The THC level usually peaks in about 30 minutes, and its effects may wear off in 1-3 hours. If you drink or eat pot, it make take many hours for you to fully sober up. You may not always know how potent your recreational marijuana might be. That also goes for most medical marijuana.
It May Affect Your Mental Health
Not everyone’s experience with marijuana is pleasant. It often can leave you anxious, afraid, or panicked. Using pot may raise your chances for clinical depression or worsen the symptoms of any mental disorders you already have. Scientists aren’t yet sure exactly why. In high doses, it can make you paranoid or lose touch with reality so you hear or see things that aren’t there.
Your Thinking May Get Distorted
Marijuana can cloud your senses and judgment. The effects can differ depending on things like how potent your pot was, how you took it, and much marijuana you’ve used in the past. It might:
- Heighten your senses (colors might seem brighter and sounds might seem louder)
- Distort your sense of time
- Hurt your motor skills and make driving more dangerous
- Lower your inhibitions so you may have risky sex or take other chances
You May Get Hooked
About 1 in 10 people who use pot will become addicted. That means you can’t stop using it even if it harms your relationships, job, health, or finances. The risk is greater the younger you start marijuana and the more heavily you use it. For instance, the odds of addiction are 1 in 6 if you use pot in your teens. It might be as high as 1 in 2 among those who use it every day.
You could also grow physically dependent on marijuana. Your body could go into withdrawal, leaving you irritable, restless, unable to sleep, and uninterested in eating. Learn more about how to spot the signs of marijuana addiction.
It May Impair Your Brain
Marijuana can make it harder for you to focus, learn, and remember things. This seems to be a short-term effect that lasts for 24 hours or longer after you stop smoking.
But using pot heavily, especially in your teen years, may leave more permanent effects. Imaging tests with some — but not all — adolescents found that marijuana may physically change their brains. Specifically, they had fewer connections in parts of the brain linked to alertness, learning, and memory, and tests show lower IQ scores in some people.
Your Lungs May Hurt
Pot smoke can inflame and irritate your lungs. If you use it regularly, you could have the same breathing problems as someone who smokes cigarettes. That could mean ongoing cough with colored mucus. Your lungs may more easily pick up infections. That’s partly because THC seems to weaken some users’ immune systems.
It May Ease Your Pain and Other Symptoms
Medical marijuana is legal in some form in a majority of states. And more than 10 states and Washington, DC, have legalized recreational pot. But the federal government’s ban on marijuana has made it hard to study its effects on humans. Limited research shows that medicinal pot might help:
- Ongoing pain (This is the most common use and a well-proven benefit of medical marijuana.)
- Stiff muscles or muscle spasms from multiple sclerosis. People with MS report stronger improvements compared to measurements by experts
- Sleep problems for those with fibromyalgia, MS, and sleep apnea
- Loss of appetite and weight loss in people with AIDS
- Nausea or throwing up from chemotherapy
- Seizures from epilepsy
- Dravet syndrome or Lennox-Gastaut syndrome
You May Feel Hungrier
Many people who use weed regularly notice that it boosts their appetite. They call this “the munchies.” Some research suggests that might help people with AIDS, cancer, or other illnesses regain weight. Scientists are studying this and whether it’s safe.
It May Harm Your Heart
Marijuana makes your heart work harder. Normally the heart beats about 50 to 70 times a minute. But that can jump to 70 to 120 beats or more per minute for 3 hours after the effects of pot kick in. The added strain plus tar and other chemicals in pot may raise your chance of heart attack or stroke. The danger is even bigger if you’re older or if you already have heart problems.
It Intensifies Alcohol’s Dangers
More than 1 in 10 drinkers say they have used marijuana in the past year. Combining alcohol and pot at the same time roughly doubled the odds of drunk driving or legal, professional, or personal problems compared to drinking alone.
Your Newborn Might Be Underweight
Mothers who smoke pot while pregnant face a higher risk of giving birth to underweight or premature babies. But researchers don’t know enough to say if those infants are more likely to grow up to struggle in school, use drugs, or have other problems in life.
Connection to Cancer Is Unclear
Researchers haven’t found any links between smoking weed and cancers in the lung, head, or the neck. Limited evidence suggests that heavy marijuana use may lead to one type of testicular cancer. We don’t have enough information whether cannabis may lead to other cancers, including:
- Non-Hodgkin’s lymphoma
It’s short for cannabidiol, a substance found in both marijuana and hemp plants. It doesn’t make you high. CBD can be made into CBD oil and sold as pills, gels, creams, and other formulas. Some people use CBD to treat pain, seizures, and other health problems. But scientists aren’t yet sure how well it works or if it’s safe over the long term. Lack of regulation means you can’t always know exactly what you’re buying.
Ways to Use Marijuana
You can use pot in a variety of ways. Smoking usually offers the quickest way to feel its effects:
- Rolled cigarettes
- Small handheld pipes
- Water pipes, called a bong
- A cigar that has been hollowed out and refilled with marijuana, called a blunt
- Sticky resins drawn from the cannabis plant. Resins often are loaded with much higher amounts of THC than regular marijuana
You also can mix pot into brownies, cookies, candy, tea, and other foods. Eating and drinking the drug delay the high because it has to travel through your digestive system before the THC gets into your bloodstream. So it may take 30 minutes to 2 hours before you feel anything. But edibles give you a high that lasts much longer — up to 8 hours — than if you smoke or vape weed.
American Cancer Society: “Marijuana and Cancer.”
National Health Service (UK): “Cannabis: the facts.”
Cannabis and Cannabinoid Research: “An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies.”
CBD.org: “The Care By Design product family.”
CDC: “Marijuana and Public Health.”
Colorado Department of Public Health: “FAQ — Health Effects of Marijuana.”
Consumer Reports: “What Is CBD? What to Know Now About This Cannabis Product.”
Epilepsy Currents: “Cannabidiol: Promise and Pitfalls.”
European Journal of Pain: “Transdermal cannabidiol reduces inflammation and pain-related behaviours in a rat model of arthritis.”
Government of Canada Department of Public Health: “Health effects of cannabis.”
Harm Reduction Journal: “Cannabis and tobacco smoke are not equally carcinogenic.”
Journal of Epilepsy Research: “Cannabinoids in the Treatment of Epilepsy: Hard Evidence at Last?”
Journal of Experimental Medicine: “Cannabinoids suppress inflammatory and neuropathic pain by targeting α3 glycine receptors.”
Mayo Clinic: “Marijuana,” “Medical marijuana.”
National Academies Press: “The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research.”
National Cancer Institute: “Cannabis and Cannabinoids (PDQ®)–Health Professional Version.”
National Institute on Drug Abuse: “Marijuana,” “What is marijuana?” “How does marijuana work?” “Secondhand Marijuana Smoke?” “What are marijuana’s effects on lung health?” “What are marijuana’s long-term effects on the brain?” “Researching Marijuana for Therapeutic Purposes: The Potential Promise of Cannabidiol (CBD).”
Nemours Foundation: “Marijuana.”
New England Journal of Medicine: “Adverse Health Effects of Marijuana Use.”
Michele Baggio, University of Connecticut; Alberto Chong, Georgia State University: “Recreational Marijuana Laws and Junk Food Consumption: Evidence Using Border Analysis and Retail Sales Data.”
University of Mississippi: “Marijuana Research.”
FDA: “FDA approves first drug comprised of an active ingredient derived from marijuana to treat rare, severe forms of epilepsy.”
World Health Organization: “Cannabis.”
Alcoholism, Clinical and Experimental Research: “Simultaneous vs. concurrent use of alcohol and cannabis in the National Alcohol Survey.”
Annual Review of Clinical Psychology: “Medical Marijuana and Marijuana Legalization.”
Pot, weed, dope, or marijuana. No matter what you call it, here’s what it will do to your body and brain.