You don’t have to argue with most people about tobacco being bad for the heart. Marijuana has been a different story: It’s not seen by the general population as a drug that causes cardiovascular damage.
That story is (thankfully) changing.
There has been an avalanche of recent evidence showing that marijuana use is linked to worsened heart health across every category. Study after study connects it to severe risks of heart attack and stroke and degraded heart health in general. Below you can find a collection of resources that demonstrate and flesh out this link. This information is important not only to protect personal health, but also to explode the myths propagated by industry advocates that using marijuana doesn’t have any physical risks.
The Basics
First things first: Let’s take a basic overview of the mechanisms through which marijuana use affects heart health. There are four main ways the drug does its damage.
The “lining” of your arteries stops behaving
This is called endothelial dysfunction. The endothelium or “lining” helps your arteries dilate so blood can flow through easily. Marijuana smoke and edibles hamper the endothelium’s ability to dilate, and this reduced capacity can lead to all sorts of complications (plaque buildup, oxygen reduction, clots, blockages).
The sympathetic “gas pedal” overpowers the parasympathetic “brake”
THC stimulates the nervous system; that raises the heart rate and oxygen demand, provoking blood-pressure swings.
When oxygen demand outstrips supply, you can get ischemia (reduced blood supply) and that can tip into acute coronary syndrome. That’s when the blood flow to the heart is suddenly reduced or stopped—potentially leading to death.
Combustion toxins (smoking/vaping)
Marijuana smoke contains carbon monoxide, hydrocarbons, and other irritants which can cause inflammation and endothelial damage. These have been associated with tobacco for some time; their link to marijuana has come under scrutiny only more recently.
Dose and frequency effects
A dose-response relationship means the more you do something, the stronger the outcome is. Research shows that the more you use marijuana, the more severe the impact will be on your heart. This is especially the case with high-potency products.
A Deeper Dive
The studies gathered below contain the nitty-gritty science behind the relationship between marijuana use and cardiovascular health and explore just how badly the drug damages health across the four mechanisms described above. And it’s important to remember that the data presented here do not exhaust the studies showing weed hurts heart health. They are just a few more recent examples.
This meta-analysis from June 2025 should set everyone’s alarm bells ringing. The authors looked at twenty-four studies that investigated marijuana use and its relationship to major adverse cardiovascular events (MACE). MACE are serious and potentially life-threatening conditions that affect the heart and blood vessels like heart attack and stroke.
The results? The review found that marijuana use was associated with a 29% increase in experiencing acute coronary syndromes (ACS), a 20% increase in having a stroke, and a 110% increase in experiencing cardiovascular death—i.e. a death related to the heart.
- The Guardian: The British paper’s article noted that the BMJ research “was an exhaustive analysis of published data on the potential association between cannabis use and major cardiovascular disease and provided new insights from real-world data” and cited the researchers’ suggestion that the drug should be looked on as similar to tobacco in terms of its cardiovascular risks.
- CNN: This article highlighted the fact that the data reveal these cardiovascular harms are not affected by age—i.e., the study found that young users faced these elevated risks as well, along with the fact that these young users also lacked a history of cardiac problems. In other words, it’s the drug doing the damage.
Association of Endothelial Dysfunction With Chronic Marijuana Smoking and THC-Edible Use (JAMA Cardiology)
This May 2025 study examined healthy adults, aged 18-50, all of whom did not smoke or vape tobacco. The authors examined whether chronic marijuana use—either by smoking marijuana or consuming THC edibles—impairs vascular endothelial function. The ability for vascular endothelial cells to dilate or expand is a good proxy for the general health of the cardiovascular system.
The study looked at a characteristic called flow-mediated dilation (FMD) in arteries. The FMD number for non-marijuana users was on average 10.4%. Lower numbers are worse, here, and the researchers found that users who smoked had mean FMD numbers of 6% while edible users had mean FMD numbers of 4.6%. That translates to a drop of 42% in FMD for smokers and of almost 56% for edible users. Those are massive deficiencies and they suggest that both chronic marijuana smoking and THC ingestion are associated with endothelial dysfunction. Frequency of use and higher THC-content were related to worsened endothelial function.
- New York Post: This article cites one of the study’s authors, Matthew Springer, making a crucial point. “Scientifically, this THC result is really interesting but boy does it screw up the public health messaging.” I.e., tobacco is correctly held to be a terrible cardiovascular danger, but marijuana—thanks to industry propaganda—had erroneously come to be seen as a “safer” replacement. It’s not. This study blows up that myth forever.
- People: The lifestyle-celebrity-gossip magazine turned surprisingly serious when it addressed the risks this study raised. The article details not only the JAMA study but gives a decent thumbnail history of the longer-term science around this issue. The fact that this coverage appeared at all is great news, especially on edibles: People’s audience is primarily female and edibles remain the overwhelming choice of delivery method of women who use the drug.
Risk of Myocardial Infarction in Cannabis Users (Journal of the American College of Cardiology)
This massive March 2025 meta-analysis from JACC—it surveyed outcomes among more than 75 million patients—uncovered some very disturbing results.
Over an average follow-up of over three years, past marijuana users had (compared to non-users) a more than sixfold risk of heart attack, a fourfold risk of ischemic stroke, a twofold risk of heart failure and a threefold risk of cardiovascular death, heart attack, or stroke. Unsurprisingly, and tragically, the study also determined that active marijuana users were 1.5 times as likely to suffer a heart attack compared with those who are not marijuana users.
VIDEO: Good Morning America takes on the cardio risks of weed
Association of Cannabis Use With Cardiovascular Outcomes Among US Adults (Journal of the American Heart Association)
This study of over 430,000 adults found that marijuana use is associated with increased risk of adverse cardiovascular outcomes, including myocardial infarction (heart attack) and stroke. Daily marijuana users had a 25% higher odds of heart attack and 42% higher odds of stroke compared to non-users—and more frequent use led to higher risk. Among adults who had never used tobacco, daily marijuana use was linked to even higher odds: a 49% increased risk of heart attack and more than double the risk of stroke.
This strongly suggests marijuana use independently raises the risk of premature heart disease. Marijuana use and especially frequent marijuana use is a significant and independent risk factor for heart attack and stroke, even in the absence of tobacco use.
VIDEO: CBS on the linkage between marijuana, heart attacks, and stroke
Further Reading
Here are some items that round out a current and complete understanding of the relationship between marijuana use and heart health.
(Newsweek) Marijuana Could Break Your Heart—Literally: A piece by Dr. Kevin Sabet that goes beyond distilling the pile of recent studies that link marijuana use with bad heart health. It also contextualizes that recent spate of studies in terms of research going back decades and calls for people to do their due diligence and spread awareness now.
Delta-8 ruins hearts and lives: Kelly Turner’s story: Kelly Turner’s son had thought nothing could go wrong when he took three hits of a Delta-8 THC vape pen, Delta-8 THC being a psychoactive substance found in the hemp plant. But as Kelly found out, Delta-8 can be just as dangerous and life-altering. The few hits made his heart go haywire; it was extremely close to giving out. Thankfully, he survived, but that day continues to define the family’s lives through his ongoing health struggles.
Triggering myocardial infarction by marijuana (Circulation): This 2001 study by Harvard researchers shows that the risk of having a heart attacks leaps almost fivefold—yes, you read that right—in the 60 minutes after using marijuana. In other words, the science on just how dangerous weed is for your heart goes back a lot longer than just the past couple of years.