Marijuana Legalization Can Help Solve the Opioid Problem


Marijuana Legalization Can Help Solve the Opioid Problem

Marijuana legalization is chipping away at the social and personal harms of dangerous drug use more effectively and vastly less expensively than the failed War on Drugs.

The U.S. has spent over a trillion dollars during four decades on the “War on Drugs,” with little to show for it. That “war” has sought to eliminate certain drugs rather than the harms associated with them (such as addiction, overdoses, and harmful acts perpetrated by drug users). Ironically, many of these harms have been partially mitigated at surprisingly low costs—not by the ill-conceived War on Drugs, but by ending the war on one drug, marijuana. Legalizing marijuana is reducing the social harms related to drug use by exerting its own pincer movement through simple supply and demand.


Proponents of the War on Drugs have the “opioid crisis” in their sights. According to a report by the Council of Economic Advisors, opioid use cost U.S. taxpayers about $500 billion in 2015, primarily as a result of additional health care expenditures and losses in productivity, on top of the $8 billion spent on criminal justice enforcement.

It’s difficult to measure the extent of opioid use—and therefore demand—because so much of it is illegal. Illegal use is typically observed primarily through the arrest, death or hospitalization of users. If those statistics increase sharply (which they have), we can assume that use has increased, but such metrics do not capture the actual extent of use.

But while demand for opioids seems to have risen, the rate of increase has been higher in some places than others. In particular, in places where medical cannabis is legal, marijuana has likely at least partially displaced opioids.

Canada has had a comprehensive national program of legalized medical cannabis since 2014. A recent University of British Columbia patient survey found 63 percent of Canadian opioid prescription drug patients had substituted cannabis for prescription drugs, 30 percent of which were for opioids. These patients cited fewer side effects, less addictivity and better symptom management.

In the states where it’s legal, medical marijuana is likely serving the same purpose for many U.S. opioid users. Twenty-nine states and the District of Columbia have legalized medical marijuana. A 2014 study found that in states that had legalized medical marijuana between 1999 and 2010, the incidence of opioid mortality was lower than in states where marijuana was not legalized for medical purposes. Meanwhile, a more recent study found that medical marijuana legalization was associated on average with 23 percent fewer opioid-related hospitalizations.

Opioids are powerful analgesics and as such have substantial benefits for pain management. However, opioid users may have trouble gauging safe dosage, especially when they are unaware of the actual dose of the opioid they are taking—a common problem with opioids purchased illegally. But they don’t have that problem if they switch to marijuana, which has no known lethal dose. According to the National Cancer Institute, “Because cannabinoid receptors, unlike opioid receptors, are not located in the brainstem areas controlling respiration, lethal overdoses from Cannabis and cannabinoids do not occur.” For those opioid users who have become addicted to opioids, substituting a drug that is not physically addictive and has no known lethal dose can only be a positive step.

While legalized medical marijuana results in relatively fewer opioid deaths, legalizing marijuana for recreational use seems to have resulted in an absolute reduction in such deaths. A 2017 study published in the American Journal of Public Health found that opioid mortality rates in Colorado fell following the legalization of recreational marijuana, reversing an upward trend in opioid deaths.

The stated preference of many opioid users for marijuana, combined with lower opioid hospitalization and mortality, means legalized marijuana likely correlates to a lower demand for opioids and a higher demand for marijuana.


Over time, the price of recreational marijuana in Colorado and Washington has fallen. That’s because legalization, when it’s done right, drives competition and that drives innovation, leading to more efficient production and distribution. Ideally, prices fall below black market rates, thereby supplanting the black market created by prohibition.

Illegal substances are more risky to produce, transport and sell because every party faces the possibility of criminal sanction. Moreover, the inability to enforce agreements legally means that enforcement typically comes by way of a gun. So the prices of illegal substances tend to be higher than their legal equivalents—to compensate parties for the additional risks they face and because illegal markets tend to be subject to local monopolies. This results in a cascade of unintended, harmful consequences to society. Full legalization removes these risks to producers, sellers and users, thereby eliminating the associated violence and related social harms. 


Legalization of marijuana would bring transparency to business transactions and address many goals that the War on Drugs has failed so miserably to achieve:

Reduced harmful drug use: With legal options, both recreational and therapeutic drug users are less likely to use and become addicted to more-dangerous substances, as found above with opioids.

Decreased overdose mortality: According to the American Society of Addiction Medicine, “Drug overdose is the leading cause of accidental death in the US, with 52,404 lethal drug overdoses in 2015. Opioid addiction is driving this epidemic, with 20,101 overdose deaths related to prescription pain relievers, and 12,990 overdose deaths related to heroin in 2015.” When legal or illegal opioid use is displaced by legal marijuana use, overdose mortality declines, as found in Colorado. And it does so at no cost to the taxpayer (indeed, since legal weed is taxed, it actually generates revenue). As such, it is a highly cost-effective way to address this tragic problem.

Mortality from illegal opioids is typically due to overdose. That can be simply the result of a mistake on the part of an addict. But it is often caused or exacerbated by drugs that do not contain what vendors claim they contain. Often fentanyl is cut into or sold as heroin. With fentanyl’s vastly lower lethal dose, heroin users are more likely to overdose.

Tainted drugs also play a part. Sellers can derive greater profits when cutting heroin or fentanyl with visually similar substances, such as laundry detergent and strychnine. Opioid users who substitute marijuana also run the risk of tainted product in states where marijuana is illegal. Illegal marijuana is sometimes moistened with water or even Windex as a means of increasing weight or volume and masking the smell of mold.

But with legalization comes known supply chains, reputation and liability (customers can sue if they are sold a tainted product). That means cannabis bought legally is far less likely to be cut with unknown and possibly toxic substances, or let to mold. Customers of legalized marijuana can know the strength of what they’re buying, unlike buying in the black market, which means a more informed consumer who can make better choices about product and dose.

Reduced drug-related incarceration rates: By definition, legalization brings a lower incarceration rate, but that’s not the goal here. After all, legalizing murder would cause the homicide incarceration rate to plummet! An incarcerated murderer is less likely to murder others. But when a substance that is far less lethal than alcohol is banned, arguably justice is out of whack and incarceration is uncalled for. The ACLU found that in 2010 American police arrested more people for (typically small amounts of) marijuana than for all other illegal drugs combined. This has cost taxpayers billions of dollars and has inflicted pain on many young lives unnecessarily and unfairly, and not only through incarceration. Merely having an arrest record prevents many from gainful and productive employment. Legalization rectifies this imbalance of justice, relieves overwhelmed prisons, and does not arbitrarily favor alcohol over marijuana. 

Reduced dangerous drug availability: We’ve learned through the failed War on Drugs that availability (supply) cannot be legislated away. The only effective recourse is lowered demand. While demand for marijuana has increased in states where it is legal, it appears to be displacing use for more-dangerous drugs—a welcome trade-off.

Reduced social harms: With marijuana legalization cutting the black market price, drug cartels have had to abandon marijuana trafficking in favor of heroin and other opioids that can still turn a profit on the black market. With a reduced share of the market comes reduced illicit drug activity and all the social harm it engenders, such as rampant theft and other property crime, street violence, territorial shootings and other gang-related illicit drug activity. This decreases violence, which often spills over into mainstream society, especially in places with high illicit drug use and trafficking.

Marijuana legalization is chipping away at the social and personal harms of dangerous drug use more effectively and vastly less expensively than the failed War on Drugs. While it’s less offensive to blame other nations than ourselves, interdiction doesn’t lessen demand for illegal drugs in this country: it makes them scarce and expensive, and drives a host of black market, underground, violent criminal enterprises. Moreover, it costs billions of dollars that could be used for other more socially useful purposes, including prevention and treatment of addiction. Conversely, marijuana legalization moves transactions into legal markets, allowing a vastly safer alternative for recreational and medical opioid users.

In economics 101, students learn about the “laws” of supply and demand. The War on Drugs has been waged in ignorance of this lesson. Legalization of marijuana shows that those laws still prevail and can be used to win the war on social harms from drugs.

Teri P. Moore is a policy analyst and editor at Reason Foundation.