Proposals to cap the amount of THC in cannabis flower and concentrates have been gaining traction in a number of state legislatures, and earlier this week the idea reached the federal level.
In a report released on Wednesday, the US Senate’s Caucus on International Narcotics Control recommended looking into THC caps on state-legal, regulated products. Politico was first to break the news of the report, which was led by Sen. John Cornyn (R-TX) and Sen. Dianne Feinstein (D-CA), co-chairs of the Senate caucus. Cornyn and Feinstein are longtime opponents of cannabis legalization.
Most cannabis flower in America’s legal regulated markets ranges between 18% and 23% THC. Cannabis concentrates, including vape cartridge oils and dabbing products like wax, shatter, and distillate typically contain THC levels from 70% to 90%.
Proposals to limit THC levels often aim to cap the allowable level of THC at 15% or lower. THC is the main psychoactive ingredient in cannabis, but it is not the only psychoactive cannabinoid. The legal definition of hemp, which cannot go above 0.3% THC, is the fullest expression of a THC cap currently in place in the United States.
Public safety at issue
Proponents of these THC caps—who are often the same politicians who stood against legalization and lost—contend that limiting THC levels will increase public safety. Pushing back are many cannabis experts and legalization advocates, who say THC caps will cause far greater harm by forcing consumers back to illegal markets.
A return to unregulated marketplaces is troublesome, particularly when it comes to vape cartridge oils. The 2019 EVALI/VAPI health crisis was caused by illegal-market vape cartridge manufacturers introducing toxic thinners into their products.
Forcing patients to purchase more
Florida for Care Executive Director Ben Pollara, the legalization advocate who helped lead Florida’s successful medical marijuana campaign in 2016, pointed out another problem in a recent op-ed published in the Fort Myers News-Press.
Florida State Sen. Ray Rodrigues (R-Fort Myers) is championing a bill that would impose a limit of 10% THC on all medical marijuana products. Doing so, Pollara wrote, would effectively force a 50% to 150% tax on patients. Here’s how Pollara explained it:
“Patients will feel the effects of THC caps almost immediately,” Pollara added. “Many will be priced out of what patients already complain is a too expensive medical marijuana program, instead seeking out the black market.”
Another way to prohibit cannabis
Historically, the idea of THC caps stretches back to 2016, when cannabis prohibitionists in Colorado, having failed to stop adult-use legalization, attempted to float a statewide initiative to limit THC potency to 15%.
That effort failed to make the ballot, but the idea survived. In 2019, Sen. Mike Crapo (R-ID), then chair of the US Senate banking committee, indicated he was considering a 2% THC cap on cannabis products produced or sold by businesses that want secure financial services under the SAFE Banking Act, which is still in motion. Such a cap would render the SAFE Banking Act all but useless, as most cannabis products contain far more than 2% THC.
Crapo’s arguments for the cap were similar to those being expressed by Cornyn and Feinstein in the caucus report earlier this week: THC-related impaired driving, and the “harmful effects of THC use during pregnancy and on young developing brains.” Crapo offered no evidence indicating that a THC cap would lead to lower usage levels by pregnant women or minors.
Revival of cap bills in 2020
The idea of imposing THC caps on cannabis gained further momentum in 2020 when legislators in several states, including Florida, Arizona, Iowa, Washington state, and Colorado, introduced bills to limit THC levels in both flower and concentrates. None of those efforts passed, in part due to the early closure of many state legislatures following the coronavirus outbreak.
A bill to cap THC was shot down in the Florida Legislature last year, but state Sen. Rodrigues re-introduced the measure in 2021, and it’s gaining some traction in Tallahassee.
State Agriculture Commissioner Nikki Fried, whose agency regulates hemp cultivation (but not medical marijuana), recently spoke out against the proposed THC limits.
Previous caps didn’t work
Paul Armentano, deputy director of NORML, has seen a number of different THC caps tried by states over the years. “Vermont’s adult-use law imposes caps on retail products,” he wrote in an email to Leafly. “30% for flower, 60% for concentrates.” The 30% THC limit on flower approaches the natural limit for any cannabis plant, while the 60% THC limit for concentrates is far below what most concentrates contain.
Armentano observed that New Jersey’s medical marijuana law was initially enacted years ago with a provision placing a 10% THC cap on cannabis products—but it didn’t work. “That cap was quickly abandoned and the law was amended,” Armentano noted. He added: “Some of the states with limited low-THC/high-CBD only access options also include caps, such as Georgia, but these are not traditional medical cannabis laws.”
Iowa’s THC cap: Limiting patient choices
Iowa is one state that began its medical marijuana legalization program with extremely tight THC limits. In 2014, lawmakers established a THC cap at 3% or less for qualifying patients. In June 2020, the law was modified to add qualifying conditions and change the 3% THC cap to a per-patient purchase limit of 4.5 grams total THC over a 90-day period. Iowa does not allow the sale of smokeable flower, so patients are limited to tablets, capsules, and vape cartridges. That 90-day limit works out to 50mg per day per patient, which is not much for patients managing chronic pain or other conditions.
Here’s how that THC limit may negatively affect medical marijuana patients. Numerous studies have found that some patients managing chronic pain have been able to move off opioids, which carry the risk of addiction and overdose death, by using medical marijuana as a substitute. Cannabis carries a much lower risk of dependency, and zero risk of death by overdose. By limiting a patient’s THC access to 50mg per day, Iowa’s cap may prevent chronic pain patients from moving off opioids via cannabis substitution. That 50mg dose may simply not be enough.
Zero chance of overdose death from THC
It is impossible to fatally overdose from ingesting too much THC. High concentrations have shown adverse effects in some people, including increased anxiety and nausea. It is widely accepted both within the cannabis community and beyond that cannabis use can be harmful to developing brains. In legal US states, access to cannabis has been limited to those 21 and older in adult-use markets. In Canada, the minimum legal age varies—in some provinces it’s 18, in some it’s 19, and in some it’s 21.
Old discredited tropes repurposed
According to NORML officials, the idea of imposing THC caps relies on old and discredited prohibitionist tropes.
“Sensationalist claims alleging that today’s marijuana is far more potent, and therefore inherently more dangerous to society than the cannabis of the prior generations are nothing new,” said a NORML press release on the issue. “Such claims first emerged in the 1980s and continue to this day. That said, there exists little data substantiating fears that these products pose any sort of unique health threat. In fact, higher potent cannabis products, such as hashish, have always existed and essentially, marijuana is still the same plant it has always been — with most of the increase in strength akin to the difference between beer and wine, or between a cup of tea and an espresso.”
Instead of attempting to regulate THC content, NORML officials say, lawmakers should productively address public health concern by “arming the public the with better public safety information about the effects of more potent products” and offer “further diligence on the part of regulators to ensure that legal products do not get diverted to the youth market.”
NORML State Policy Manager Carly Wolf called THC caps “arbitrary, and [they] are not in the best interest of consumers and especially medical marijuana patients who need and deserve the legal option to access varying strains of cannabis in varying potencies. Alcohol and other prescription medications are already available in a variety of potencies, and similarly to cannabis, consumers self-titrate their dosages accordingly, consuming lesser amounts of higher potency products.”
Stigma persists around THC
While the expanding cannabis legalization movement shows that most of the world believes cannabis to be a relatively safe substance, the stigma around cannabis use, particularly the intoxicating high caused by THC, persists. But Ben Pollara, among others, argues that THC is one of the most beneficial aspects of the plant.
“THC is one of many chemicals in marijuana but is by far and away the most active one,” Pollara writes. “It is also the one which produces the most and strongest medicinal effects for patients.”