Federal legalization of cannabis would provide an opportunity to set regulations that better protect public health, researchers say.
In a white paper published July 18, researchers at the University of Southern California’s Leonard D. Schaeffer Center for Health Policy & Economics outlined several potential policies that could be enacted by the federal government if it decriminalizes cannabis.
This includes placing limits on the amount of tetrahydrocannabinol (THC) — the main psychoactive compound in cannabis — that can be included in products, and restricting how much individuals can buy at one time based on the amount of THC in the product.
Other policies include taxing cannabis products based on potency rather than weight or retail price and tracking all cannabis or hemp from cultivation to being sold as a product.
Health risks of high-potency cannabis products
A July 2022 studyTrusted Source published in The Lancet Psychiatry suggests that people who use higher-potency cannabis have a higher risk of developing cannabis use disorder. They are also more likely to experience a psychotic disorder, such as schizophrenia.
According to the USC white paper, other research has shown that legalizing cannabis at the state level is linked to an increase in cannabis-related visits to the emergency department by children and teens, and a rise in cannabis-involved impaired driving.
“A public health approach to cannabis regulation is about incentivizing users in a manner that maximizes benefits and reduces harm,” Rosalie Liccardo Pacula, PhD, a senior fellow at the USC Schaeffer Center and Elizabeth Garrett Chair in Health Policy, Economics & Law at the USC Price School of Public Policy, told Healthline.
Pacula added that a public health approach to how cannabis products are sold and developed is “mindful that higher levels of THC induce more impairment and more health risks.”
Cannabis laws vary by state
In the United States, cannabis is illegal at the federal level, although many states have passed laws allowing medical and/or recreational use of cannabis.
A bill introduced in the U.S. Senate on July 21 would decriminalize cannabis at the federal level and allow states to set their own cannabis laws. Other bills in the House and Senate are in the works.
While this may seem like a positive development for cannabis enthusiasts, Pacula expressed concern. “If the federal government legalizes cannabis without putting in a [THC] cap, we won’t ever get one,” she said. “The only states that have put potency caps in place have been the ones that did it when they first legalized cannabis.”
Current state cannabis laws vary in terms of limits on purchase quantities and potency limits. For example, Vermont and Connecticut are the only states that have set THC potency limits for both cannabis flower and concentrates, according to USC researchers.
Pacula said the limits set by these two states are “probably reasonable for the U.S. market, although they might still be too high. But I’m OK letting that be, as opposed to not setting a cap at all.”
In addition, she and her colleagues point out that most states that limit cannabis sales do so based on product weight and type rather than the quantity of THC contained in the product. This allows people to buy a large amount of higher-potency cannabis products at one time.
Excessive cannabis use discouraged
The policies the USC researchers outline in the white paper would discourage excessive cannabis use, in particular the use of higher-THC products such as edibles and cannabis concentrates.
“Right now [cannabis] flower is the main product being sold, but we are seeing a huge shift to vape oils concentrate, while edibles have stabilized in the market,” Pacula said.
While the policies outlined in the white paper focused on the THC content of cannabis products, Liz Rogan, founder of The Cannabis Business Council of Santa Barbara County, said this misses the role that different components of cannabis may play in the intoxicating or other effects of these products.
Pacula emphasized, however, that the standards would need to adapt as additional scientific data is available on the risks associated with different doses of THC. These policy updates could also take into account new science on the effects of other components of cannabis.
“It took us decades to understand alcohol and what a standardized drink was,” Pacula said. “So we should set these caps and wait at least 5 years before we adjust them because it’s going to take some time for the science to come out.”
Some concerns about THC caps
R. Lorraine Collins, PhD, professor and associate dean for research in the University at Buffalo’s School of Public Health and Health Professions, supports the white paper’s proposed policies. She said that setting THC limits for cannabis products and taxing products based on THC content would be easy to implement, calling these strategies an “excellent start.”
For a THC cap to work to be effective, Collins said laws would need to cap the potency of all cannabis products, including ones that come directly from the cannabis plant and those that are derived from hemp or cannabis.
“The cannabis industry is very smart,” she said. “One of the things that they do is if you say you’re going to cap the potency of cannabis flower, they’ll increase the potency in other cannabis products. So the key is to cap THC in ‘all cannabis products.’”
In addition, she said the laws would need to be broad enough to cover cannabis products developed in the future.
As for individual limits on cannabis purchases, Collins expressed some reservations about this policy since the U.S. doesn’t have similar limits for other adult-use products such as alcohol and tobacco.
Rogan agreed: “This is an adult we’re talking about. This is somebody who should be able to make their own decisions,” she said. “It really goes back to personal choice — you have [the] freedom to do what you want; we’re hoping you’re going to be responsible.”
In addition, Collins said that individual purchase limits may not be very effective. “What’s to stop a person from going from retail outlet to retail outlet?” she said. “You could accumulate a lot of cannabis that way, even if there’s a limit on how much you can buy at a time.”
Rogan is also concerned about the impact that a cap on THC limits and purchase limits might have on people using cannabis to treat medical conditions.
“When you’re treating cancer or chronic pain, you often need high doses of THC,” she said. “So is it fair to that person to have to go to the [cannabis] dispensary every day and buy more often because they can’t buy the products in a concentrated form?”
Advantages of federal regulation
While states like Connecticut and Vermont have stricter caps on THC content, the USC researchers argue that federal regulation would ensure that public health is protected equally throughout the country.
“You’re not going to incentivize good cannabis industry standards if you let states vary these caps,” Pacula said. “It’s going to be much easier to do it on a federal level.” A federal cap, she added, would only set the maximum potency for cannabis products. States could have more restrictive laws.
In addition, there is now a precedent for the federal government to regulate the maximum THC content of cannabis products.
“The FDA, which finally did get authorization to regulate nicotine products, is able to do things like set a cap on the amount of nicotine in cigarettes, or remove certain kind of flavors from tobacco,” Collins said.
Collins noted that having different cannabis laws in each state — in particular THC caps — could lead to people in places with more restrictive laws shopping for cannabis in neighboring states with more lenient regulations. Something similar happened before all states set 21 years as the minimum drinking age for alcohol, she said.
Still, Collins said that many people will be attracted to the legal cannabis market for what it offers — being able to buy products that are safe and contain exactly what they are supposed to.
“You don’t have to worry about whether your weed is being cut with fentanyl or another drug that could do you harm,” she said. “You also don’t have to worry about poor cultivation leading to mold that could do you harm when you’re smoking cannabis.”
New research presents a compelling argument for regulating cannabis at the federal level. Decriminalizing cannabis could help limit the sales and use of high-potency cannabis products, which studies have shown pose dangers to human health.
Even with federal legalization, however, experts like Collins and Rogan say that setting caps on THC could still drive consumers to buy higher-potency products in the illicit cannabis market.
“If people are concerned about young people — especially males 26 and under — using high-THC products, the legal system is going to be better,” Rogan said. “Because at least they know what they’re getting there versus if they’re getting a product on some street corner.”