If you were asked to rank the deadliest recreational drugs, you might instinctively put heroin or cocaine at the top.
But according to a new study, the most dangerous drug is actually alcohol—a legal substance consumed by millions worldwide.
Even more shocking?
Marijuana, often demonized in drug policies, was found to be the least deadly of all.
Led by food chemist and toxicologist Dirk W. Lachenmeier, researchers analyzed a range of substances to determine how likely an average user is to overdose.
The key metric they used was the “margin of exposure” (MOE)—a ratio that compares a drug’s lethal dose to the amount typically consumed.
The results, published in Scientific Reports, revealed that marijuana is roughly 114 times less deadly than alcohol.
In fact, cannabis was the only drug classified as “low risk,” while alcohol and tobacco ranked as “high risk” substances.
This finding directly challenges long-standing drug policies that criminalize marijuana while ignoring the widespread harm caused by legal substances like alcohol and tobacco.
But before you dismiss this as just another pro-cannabis argument, let’s dive into the data—and the reasons why our perceptions of drug safety may have been completely wrong all along.
The Margin of Exposure
The margin of exposure (MOE) provides a scientific way to assess the relative dangers of different substances.
Here’s how it works:
- A higher MOE means a drug is safer—there’s a large gap between a typical dose and a lethal dose.
- A lower MOE means a drug is more dangerous—even a small increase in dose can lead to death.
Using this method, researchers analyzed legal and illegal substances, from cocaine and heroin to nicotine and alcohol.
The results were eye-opening:
| Drug | MOE (Risk Level) |
|---|---|
| Marijuana | Low Risk (Safest) |
| Alcohol | High Risk (Deadliest) |
| Tobacco | High Risk |
| Cocaine | High Risk |
| Heroin | High Risk |
“Our MOE results confirm previous drug rankings based on other approaches. Specifically, the results confirm that the risk of cannabis may have been overestimated in the past,” the researchers wrote.
In contrast, the risk of alcohol has likely been underestimated.
Wait—Is Alcohol Really More Dangerous Than Heroin?
This is where things get controversial.
At first glance, it seems absurd to suggest that a glass of wine is more dangerous than a hit of heroin. But here’s the key distinction:
- The study measures direct toxicity, not external risks.
- It looks at the likelihood of overdose, not long-term effects.
That means it doesn’t account for dirty needles, addiction, or reckless behavior. Instead, it focuses strictly on how much of a substance it takes to reach a lethal dose.
“We shouldn’t take this to mean that moderate alcohol use is more risky than regular heroin use,” notes Sean O’Kane at The Verge.
However, from a public health standpoint, alcohol is responsible for far more deaths than heroin—simply because of how widely it’s consumed.
- Alcohol-related deaths (worldwide per year): 3 million
- Heroin-related deaths (worldwide per year): 100,000
That’s 30 times higher, largely because alcohol is:
- Socially accepted and legal
- Easily accessible
- Consumed in high quantities
So while heroin is objectively more toxic, alcohol is far deadlier on a population scale.
Why Is Marijuana Still Illegal in Many Countries?
If alcohol and tobacco are more dangerous than marijuana, why is cannabis still illegal in many parts of the world?
The study suggests that government policies on drug regulation are often not based on science.
“Many governments in Europe have favored more restrictive policies with respect to illicit drugs than for alcohol or tobacco, on the grounds that they regard illicit drug abuse as a significantly larger problem for society,” the researchers noted.
However, their findings show that strict marijuana laws don’t align with the actual risk levels.
In fact, the idea that cannabis is highly dangerous has been largely exaggerated over the years.
For example:
- “Marijuana is a gateway drug” – There is no conclusive scientific evidence supporting this claim.
- “Marijuana causes fatal overdoses” – Virtually no recorded deaths have been directly linked to marijuana overdose.
- “Marijuana is as dangerous as alcohol” – Studies consistently show that alcohol is far more harmful, both physically and socially.
So why the misinformation? Decades of political agendas and outdated drug policies.
What About the Risks of Marijuana?
To be clear—just because marijuana is low-risk for death doesn’t mean it’s completely harmless.
There are still potential downsides:
- Mental health risks: Some studies suggest heavy marijuana use may contribute to anxiety, depression, and psychosis in vulnerable individuals.
- Impaired driving: While marijuana is far less impairing than alcohol, driving under the influence still poses risks.
- Respiratory issues: Smoking cannabis can irritate the lungs, though vaping and edibles reduce this risk.
Like any substance, moderation and responsible use are key.
“Everything you put in your body, whether it’s sugar, salt, or heroin, comes with associated risks,” writes Christopher Ingraham at The Washington Post.
The problem is how inconsistently governments regulate these risks.
What Should Change?
Based on these findings, researchers argue that drug policies need a major overhaul.
- Focus on real dangers: Instead of cracking down on low-risk substances like marijuana, governments should prioritize reducing alcohol and tobacco harm.
- Reevaluate cannabis laws: Countries should reconsider strict cannabis regulations, given its low toxicity and medical potential.
- Educate with science, not fear: Public perception of drug risks should be shaped by data, not outdated stereotypes.
The study’s bottom line?
If saving lives is the priority, then alcohol and tobacco should be the real focus—not marijuana.
Final Thoughts: A Wake-Up Call for Drug Policy
For decades, cannabis has been portrayed as a dangerous drug, while alcohol has been socially accepted despite causing millions of deaths.
But science tells a different story.
- Alcohol is the deadliest widely-used drug.
- Marijuana is the least dangerous in terms of overdose risk.
- Government policies often fail to reflect the actual science.
So as more countries debate legalization and drug reform, this study serves as a powerful reminder:
- It’s time to rethink what we consider “dangerous.”
- It’s time to regulate based on facts, not fear.
- And most importantly—it’s time to save lives.
What do you think? Should marijuana laws change based on this research? Let’s discuss in the comments.
Sources: The Washington Post, The Verge, Scientific Reports
