Twenty-First Century Illicit Drugs and Their Discontents: The Troubling Potency of Twenty-First Century Cannabis

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Twenty-First Century Illicit Drugs and Their Discontents: The Troubling Potency of Twenty-First Century Cannabis

December 7, 2022 About an hour read Download Report
Paul Larkin
Rumpel Senior Legal Research Fellow
Paul is a Senior Legal Research Fellow in the Meese Center for Legal and Judicial Studies at The Heritage Foundation.


Regulation of a subject like pharmacology in which scientific knowledge is essential to sound policymaking demands that the government remain flexible to respond correctly and quickly to developing subject-matter data and trends. In fact, the need for resort to scientific expertise and the need for flexibility in lawmaking are two of the principal rationales for delegating rulemaking power to administrative agencies. The greater potency of cannabis and its products that we have witnessed over the past five decades demands that we conduct any reexamination of the federal laws governing cannabis mindful of the potentially more severe adverse effects of twenty-first century cannabis. To do anything less would be irresponsible.

Key Takeaways

The cannabis that is available today is 7-30 times more powerful than the cannabis that was available in the 1960s and 1970s.

States have legalized cannabis for medical and recreational use without FDA approval or without performing the necessary safety testing themselves.

Congress and states should address the potential problems created by high-potency cannabis before there is any further discussion of legalization.

The most commonly used—and controversial—illicit drug in the United States is Cannabis Sativa L., the technical label for the plant more commonly known by its slang name of marijuana.REF Advocates for liberalized regulation of cannabis have portrayed it as a mild intoxicant and social lubricant that is not materially more harmful to the body or soul than alcohol, a drug that has played those roles since Noah became the first vintner.REF Proponents of legalization also have argued that cannabis has numerous legitimate medical uses for the treatment of disease or alleviation of pain.REF Opponents of legalization have argued that numerous studies and meta-analyses dispute those conclusions.REF Those parties have also warned that cannabis’s advocates have ignored or understated various cannabis-use harms, such as increased risk for motor vehicle accidents, psychotic symptoms, violence, and amotivational syndrome.REF Those parties caution against making a radical change to our longstanding cannabis policy that could mistakenly endorse a socially damaging and irreversible new legal régime.REF

Unfortunately, “cannabis policy has raced ahead of cannabis science.”REF Since 1996, when California adopted the first medical-use cannabis régime, 37 states, four territories, and the District of Columbia have revised their laws to permit the use of cannabis products for medical purposes, while 18 states, two territories, and the District of Columbia permit recreational-use cannabis.REF In so doing, states adopted medical-use or recreational-use marijuana programs without first analyzing whether today’s cannabis poses health risks not seen in the 1960s, a time when cannabis emerged as an iconic symbol of a generation that thought it could solve every social ill, right every wrong, and eliminate every unjustified restraint on individual liberty.REF

It is a serious mistake not to analyze the potency of any drug before legalizing it. For more than 80 years, the nation has endorsed the judgment that no one should be free to distribute any “new” drugREF in interstate commerce unless and until the U.S. Food and Drug Administration (FDA), acting under the authority granted the agency by the Federal Food, Drug, and Cosmetic Act (FDCA) of 1938,REF has found (inter aliaREF) that it is “safe” and “effective” for its intended use.REF The FDA did not make any such findings before the states adopted their medical-use and recreational-use cannabis programs. In fact, the FDA and other allied federal health care agencies have consistently found that botanical cannabis is not a legitimate medication.REF The states decided to take the law into their own hands without bearing the burden that federal law places on the FDA.

That was a grievous error.REF As Dr. Nora Volkow, Director of the National Institute on Drug Abuse, has noted, “increase in THC content”—THC is the acronym for delta-9-tetrahydrocannibinol, the psychoactive compound in cannabis—“raises concerns that the consequences of marijuana use may be worse now than in the past.”REF That is why Doctor Volkow has questioned “the current relevance of the findings in older studies on the effects of marijuana use, especially studies that assessed long-term outcomes.”REF Too often over the past three decades, states have legalized cannabis without waiting for the federal government to conduct that research or performing it themselves. Moreover, much of the debate that we have witnessed during those years was biased toward one side or the other. As Carnegie-Mellon University Professor Jonathan Caulkins, an expert on cannabis, wrote in 2016, “Unfortunately, there is very little in the way of intellectually honest marijuana policy analysis.”REF

This Legal Memorandum is the third in a series of Heritage Foundation studies published under the overall title “Twenty-First Century Illicit Drugs and Their Discontents.” This paper highlights the need to consider the far greater potency of today’s cannabis when debating whether to legalize that drug.

Federal Regulation of Cannabis

Before 1996, the potency of cannabis was never an important public policy issue. Although widely available, cannabis was contraband, and its potency was minimal. Since 1996, however, and particularly after 2009, cannabis has become a lawful article of commerce in many states under state law, and its potency has expanded over that period. Yet, despite the fact that numerous states have medical-use programs, the far greater potency of cannabis today has not received the attention that the issue deserves, even though it is standard practice for the government to devote considerable attention to deciding exactly what potency a drug should have to be marketed in interstate commerce. The states’ failure to confront that issue, along with the FDA’s refusal to take control of the regulation of cannabis, has led to the situation that we see today—one in which there is little regulation of the psychoactive ingredients in cannabis despite the risk that highly potent cannabis can have severe adverse effects on long-term users.

Before 1996: Uniformity. Cannabis is an ancient nostrum. Archaeological evidence reveals use of the agricultural form of cannabis more than ten thousand years ago.REF It was lawfully grown and used in the United States for more than 100 years after 1787. Nonetheless, during the first third of the 20th century, all 50 states outlawed its use for medical or recreational purposes.REF Congress followed suit in legislation enacted in 1937REF and 1970.REF The executive branch also entered into several international conventions that require signatories to treat cannabis trafficking as a crime.REF The legal debate over the status of cannabis appeared to be settled.

It wasn’t.

Cannabis became a controversial social issue by late in the 1960s (if not earlier).REF There was a considerable debate over two issues: whether cannabis had potentially beneficial uses that justified its legalization and whether cannabis possession and use should be decriminalized—treated as a minor infraction rather than a felony—given its dissimilarities to “hard” drugs such as heroin.REF The debate was a lively one.REF Some states and localities reduced the penalty for possession of a small amount of cannabis to a minor infraction.REF At times it appeared that reformers might succeed in legalizing cannabis.REF Their efforts, however, failed in the 1970s. Although the debate continued,REF cannabis remained contraband.REF

1996–2009: The Adoption of Medical Cannabis Initiatives. For advocates of liberalized cannabis use, the Age of Aquarius dawned in 1996. By a popular initiative, California adopted Proposition 215, labelled the Compassionate Use Act of 1996.REF The proposition authorized the cultivation, possession, and use of cannabis by patients for medical purposes under California law.REF That proposition established a major beachhead for recreational cannabis use. For the first time, a state had decided to break from the nation’s uniform treatment of cannabis as contraband. Gradually, other states followed California’s lead.REF

Since 2009: The Spread of State Medical and Recreational Cannabis Initiatives. The last critical date is 2009. Starting then, the Obama Administration’s U.S. Department of Justice issued a series of policy memoranda formally stating that it would not enforce federal law against parties who complied with state cannabis regimes.REF The Obama Administration also informally made it clear that it would ignore state compliance efforts as long as a state did not rub the Administration’s face in it.REF Together, those memoranda and the Justice Department’s willful blindness revealed that President Barack Obama, like Pontius Pilate, had washed his hands of the matter.REF Specifically:

President Obama gave the cannabis industry the equivalent of a Papal blessing by almost guaranteeing its members immunity from federal prosecution if they complied with state law—and then studiously ignored whether they were in fact complying. By choosing nonenforcement in lieu of persuading Congress to revise the [Controlled Substances Act], President Obama might have reached a short-term accommodation between what some think is an outdated law and contemporary social values. In Professor [Zachary S.] Price’s words, President Obama might have helped to “unstick a frozen issue” that Congress has proved unwilling to resolve itself. Maybe President Obama thought that he could force Congress to act by making a hash of our cannabis policy. If he did, he was wrong. Strike One. If he thought his actions would energize the public into demanding congressional reform, he was wrong again. Strike Two. If, however, he thought that allowing a massive number of crimes to go unprosecuted on his watch would enable the rise of a billion-dollar industry that no successor would dare seek to eliminate (that’s my guess), he might have been right about that. If that was his plan, perhaps be succeeded. Yet encouraging people to become scofflaws—pardon me, rich scofflaws—is hardly a legitimate law enforcement strategy. Strike Three.REF

As a result, there has been a sea change in state cannabis laws since 2009. As of 2022, numerous states and territories, as well as the District of Columbia, permit cannabis or its products to be used for medical or recreational purposes. In states with only medical cannabis programs, there is no shortage of physicians willing to recommend cannabis use for a host of ailments. In states with recreational-use programs, businesses are willing to sell it for its euphoric effects.REF

Where Are We Today? Three features of that history are noteworthy.

First, cannabis remains contraband under federal law. Ironically, despite the revolution in state cannabis law, the two most relevant federal statutes have remained largely unchanged.REF The Controlled Substances Act of 1970 (CSA) classifies cannabis as a Schedule I controlled substance, the category reserved for drugs that, given their disutility and inherent risks, cannot be prescribed for any purpose.REF Cannabis thus is contraband under federal law.REF In addition to the CSA is the FDCA, which (as noted above) bars the interstate distribution of a drug until the FDA has found it to be safe and effective for its intended use.REF The FDAREF may regulate cannabis either as a drug or, when it is added to food and becomes part of an “edible” product, as a food additive.REF

Nonetheless, the FDA and related federal government health-care agencies have rejected the conclusion that botanical cannabis is a “safe” and “effective” drug for any purpose.REF The Biden Administration reiterated that conclusion as recently as April 2022.REF Shortly before the 2022 midterm elections, however, the President directed two of his principal lieutenants to reconsider the scheduling of cannabis.REF Nonetheless, even if Congress or the Attorney General were to remove the CSA restraint on the distribution of cannabis, interstate distribution would remain a federal offense under the FDCA.REF

Second, physicians cannot prescribe cannabis. Neither Proposition 215 nor any later state medical cannabis scheme has authorized physicians to “prescribe” cannabis as a medical treatment; no state can modify the federal ban on the distribution of cannabis for any purpose, even one deemed a “medical necessity.”REF But the difference between a “prescription” for and “recommendation” of cannabis turned out to be macht nichts. Why? The federal courts concluded that, under the First Amendment Free Speech Clause, a physician may legally “recommend” that a patient consider using cannabis as a treatment for disease even though he cannot prescribe it, given federal law.REF Of course, the distinction between “prescribing” and “recommending” a drug that is openly sold in state-legal marijuana dispensaries (or readily available in every other state) “is about as precise as the difference between ‘dusk’ and ‘twilight.’”REF The result has been that medical-use programs opened the door for recreational-use ones. If you think that medical-use cannabis programs are just a Trojan horse for recreational cannabis use, you’re not alone.REF

Third, the debate over the pros and cons of cannabis use has not considered the high potency of today’s drug. A consequence of the states’ legalization of cannabis, coupled with the federal government’s decision to remain on the sidelines, is that businesses have competed to develop products to satisfy consumer demand. That development, as one author put it (likely with unintended sarcasm), is “a real testament to American entrepreneurialism and innovation.”REF The desire to expand market share in the pursuit of profit has led to the development of numerous, high-potency, potentially addictive, THC-infused products,REF including “edibles.”REF The ironic result of allowing the creative engine of capitalism to devise ever more powerful and dangerous forms of a quasi-legal addictive article of commerce has been damage to the lives of at least 10 percent of long-term users.REF

What has largely been overlooked in the progression from cannabis as contraband to cannabis as a quasi-legal article of commerce is the effect that this new high-potency cannabis can have on long-term users, particularly adolescents. That is striking. Analysis of the effects of a drug’s potency is critical to any discussion of its safety and effectiveness. This certainly is true in the case of standard pharmaceuticals. Drug companies test the effect of a drug’s potency on animals before conducting tests on humans.REF After obtaining those results, pharmaceutical companies then conduct what is known as Phase 1 of the standard three-phase process for the clinical trial of drugs.

The potential toxicity of a drug is an essential feature of the early stages of a drug trial because no drug can be deemed safe if the minimum lethal dose and the potential adverse long-term effects are unknown. Concern with toxicity remains a critical issue throughout the remaining phases of a pharmaceutical trial. A drug that materially reduces the size of tumors is not safe if it is toxic to the liver and kidneys. A drug that provides short-term relief from respiratory distress is not safe if it causes long-term heart failure in everyone who uses it. Yes, there are tradeoffs involved in treatment. Some patients suffering from a fatal, incurable disease might be willing to sacrifice the quality of their remaining days for a larger number of them (or vice versa). But a physician cannot responsibly offer a patient a legitimate choice if there are no known data indicating what the short-term and long-term effects of a potent drug might be. As for cannabis sold for recreational use, where no physician is involved and the only advice comes from a financially self-interested “ganjapreneur” or “budtender,” the consumer cannot expect to receive a neutral, disinterested product analysis or recommendation for use.

The bottom line is this: The states’ legalization of medical-use and recreational-use cannabis without examining or reexamining the potential harms from high-potency forms of that drug should be seen as the scandal that it is. In the rush to obtain a new source of revenue and to satisfy a vocal constituency clamoring for a substance that has the same painkilling properties as bourbon, the states have chosen to disregard the 80-plus-year judgment that American society has made to forbid large-scale commercialization of a potentially dangerous drug until after it has been proved safe and effective by its sponsors. Maybe a few of those legislators thought that they were offering a respite from pain or other consequences of the maladies that the aged and ill can suffer. Nevertheless, even if “[c]aring without science is well intentioned kindness,” it is “not medicine.”REF Any claim that smoking a joint “can cure various diseases falls along the spectrum somewhere between risible and fraudulent.”REF

What Do We Do Now? The debate over the proper legal treatment of cannabis has remained an active one for more than 50 years and shows no sign of fading away. If anything, President Biden’s October 2022 order that the HHS Secretary and Attorney General reconsider the current status of cannabis under the CSA will heighten the controversy.REF Hopefully, that review will also bring to the forefront the harms that we are now witnessing from use of the high-octane cannabis being sold today. As Carnegie-Mellon University Professor Jonathan Caulkins, an expert on marijuana policy, has admonished us, legalizing the for-profit sale of marijuana “is an irreversible leap into the unknown” and “would be next to impossible to unwind.”REF We need to debate whether the private, large-scale, commercial distribution of high-potency cannabis is a course that our society is willing to accept. We have never had that debate in Congress, and it would be criminal for its members to endorse that outcome without fully airing each side of it.

The next section makes two points: First, today’s cannabis is dramatically more potent and potentially more dangerous than grandpa’s. Second, today’s legislators and debaters must be willing to consider, and in some instances reconsider, their old positions in light of the new facts.

Increased Potency of Twenty-First Century Cannabis

Cognac might still be distilled today much as it was in the fifteenth century, but the same cannot be said of the cannabis cultivated nowadays.REF Development of sophisticated indoor and hydroponic cultivation techniques and cross-breeding has increased its potency.REF As noted above, the ganja that grandad toked during the Summer of Love had a THC content of approximately 1–3 percent.REF By contrast, the THC content in cannabis products today can far exceed what was used at Woodstock. To be sure, some people believe that cannabis was more potent in the 1960s and 1970s than we give it credit for being.REF Nonetheless, there is a consensus that cannabis is available today in far, far more powerful forms than could be obtained during those decades. Think of it as the grain alcohol version of grandad’s near-beer cannabis. Some ganjapreneurs sell forms of cannabis, known by nicknames such as “dabs” or “shatter,” that is nearly 100 percent pure THC.REF

Several factors can create variation in the amount of THC an individual consumes. To start with, cannabis is not a “standardized good”—that is, it is not a unique chemical compound and does not come with uniform and precise ingredients. Cannabis is not a lab-created pharmaceutical with precise and uniform ingredients. It is “a chemically complex and highly variable” productREF—or, to quote Dr. Robert DuPont, a former presidential drug policy advisor and Director of the National Institute on Drug Abuse, “a complex chemical slush”REF—containing hundreds of different chemicals and a variation in the THC potency. That likely is one of the reasons why the FDA has never found that cannabis is a safe and effective drug.

The different forms of cannabis products—such as the botanical flower (and its components), hash, and hash oil—vary in their composition and potency.REF The THC content can vary from 12 percent to 20 percent in the plant form or in hashish (dried cannabis resin and crushed plants). Hash oil (an oil-based extract of hashish) has a greater THC content and range, from 15 percent–65 percent. Cannabis oil extracts can be up to 80 percent THC, and crystalline forms of THC can be 99.9 percent pure.REF

A related factor is the decrease in the amount of a different cannabinoid—cannabidiol, or CBD—in twenty-first century street-level cannabis. The available evidence indicates that the two cannabinoids might produce “different, or mutually antagonistic” molecular, neuropsychiatric, and pharmacologic effects in users by reducing the adverse outcomes that high-potency THC products have on users.REF Put differently, CBD might buffer the effects of THC on the brain.REF A result is that the ratio of THC to CBD might be an important factor to consider in determining the potential adverse effects of high-potency THC.REF

Yet the cannabis sold in dispensaries and stores today generally has a low level of CBD. In fact, the THC:CBD ratio can be as high as 80:1.REF “[T]he marijuana industry has essentially bred cannabidiol out of street marijuana,” probably to attract customers by enhancing the effect of the drug.REF “That is a critical but largely undiscussed or under-discussed fact in the current debate” and demonstrates a pitfall of legalizing a cannabis industry “without an informed scientific basis.”REF That problem needs to be investigated and addressed now.

Think that’s bad enough? It gets worse.

“Synthetic cannabinoids,” known by names such as “K2” or “spice,” are new, non-botanical products synthesized in laboratories.REF One study described them as being “currently among the main players in the recreational drug market” and noted that they “represent a major challenge for health-care professionals as well as public health and law enforcement officials.”REF They are a potentially greater problem than the agricultural form of the drug. Often sprayed on herbal cannabis ingredients, synthetic cannabis binds more powerfully with CB1 receptors in the brain than the THC found in traditional joints does.REF As a result, synthetic cannabis poses even greater health risks than the botanical form poses.REF “A survey of 80,000 drug users showed that those who used synthetic cannabinoids were thirty times more likely to end up in an emergency unit than users of traditional cannabis.”REF

Among the acute adverse physical reactions to synthetic cannabinoid use are agitation, breathlessness, chest pain, tachycardia, nausea, vomiting, convulsions, and renal failure.REF Synthetic cannabinoids can be addictive,REF and their use can lead to an overdose or prove fatal.REF Adverse effects from long-term use are possible as well.REF More than 200 different types of synthetic cannabinoids have been sold over the Internet, each with a slightly different molecular structure, giving them unpredictable side effects,REF and more are being produced.REF Synthetic cannabinoids can also produce psychiatric symptoms, sometimes called “spiceophrenia.”REF Here again, science and business have combined to create a product that was not available in the 1960s and 1970s that must be analyzed from scratch today before we legalize a dangerous product.

Why Cannabis’s Increased Potency Matters

The failure of state governments to address the potential problems created by the development of high-potency cannabis before legalizing medical-use and recreational-use cannabis is a clear failure of legislative responsibility. As noted above, the FDA demands proof that a drug will not be toxic at a particular potency before it can be shipped in interstate commerce. The states have not done so, and that is utterly irresponsible. It is bad enough that the states decided to displace the FDA as the decisionmaker regarding the safety of medical and recreational cannabis. What makes that worse is that the states refused to accept the accompanying responsibility to conduct the necessary examinations of the drug that they approved for use as medicine or an intoxicant. It is no argument that the states do not have the personnel or resources to conduct the same analysis that the FDA possesses. That only goes to show why the states acted recklessly.

Because there is insufficient information to use as a basis for judgment, we cannot know exactly what the long-term effects of today’s high-potency cannabis might be. Consider just the question of whether long-term use of such a drug, particularly when begun early in a person’s life, could trigger psychosis. A future Legal Memorandum will address that issue at length. Suffice it to say here that studies and commentators have concluded that high-potency cannabis—which NIDA Director Volkow defines as any product containing more than 10 percent THCREF— is associated with various harms for users and society. People who use cannabis on a long-term basis suffer an increased risk of anomie, cannabis use disorder, psychotic symptoms, and perhaps psychosis itself because long-term use of high-potency cannabis might precipitate psychotic disorders in vulnerable individuals.REF

That is important in the case of adult users, but it is critical given the potentially life-shattering effects that early initiation and long-term consumption of today’s cannabis can have on the labile adolescent brain.REF Any discussion of the revision of our cannabis law must consider the risks that we run by allowing such a drug to be sold.


Regulation of a subject like pharmacology in which scientific knowledge is essential to sound policymaking demands that the government remain flexible to respond correctly and quickly to developing subject-matter data and trends. In fact, the need for resort to scientific expertise and for flexibility in lawmaking are two of the principal rationales for delegating rulemaking power to administrative agencies. The greater potency of cannabis and its products that we have witnessed over the past five decades demands that we conduct any re-examination of the federal laws governing cannabis mindful of the potentially more severe adverse effects of twenty-first century cannabis. To do anything less would be irresponsible.

Paul J. Larkin is the John, Barbara, and Victoria Rumpel Senior Legal Research Fellow in the Edwin Meese III Center for Legal and Judicial Studies at The Heritage Foundation.


Paul Larkin
Paul Larkin

Rumpel Senior Legal Research Fellow