Each state creates its own regulations, and products can vary a lot. The researchers say many medications are poorly labeled with misleading information about chemical contents.
"We need these consistent formulations," said RTI scientist Brian Thomas. "So that we can have product standards and quality control to assure we can manufacture them again and again in a re-producable fashion."
Ryan Vandrey from the Johns Hopkins School of Medicine spoke at an RTI webinar Thursday along with Thomas. He conducted a study measuring the drugs for THC, the main chemical in many medical marijuana products. Most products deviated from the marketed THC amount by more than 10 percent.
Mislabeled products not only mislead the customer, they can pose a health risk. Overdosing on marijuana typically isn't associated with a high risk of death, but it often leads to anxiety, paranoia, hallucinations, cardiac stress or cognitive impairment.
RTI researcher Scott Novak conducted a study showing more than 65 percent of cannabis users have overdosed in their lifetimes, which suggests to him that there's a lot of bad labeling and patients are using trial and error to find the right product.
"They are in a real search in terms of trying to figure out the appropriate dose and formulation that lines up with a way to sub-medicate their symptoms," Novak said.
It can take weeks or months to find a product that's consistent for a patient. Novak says Colorado and Washington, two states that have legalized cannabis, are starting to take the lead in standardizing labeling.
Vandrey spoke about another need for standardization - the delivery methods. Specifically, he said edible cannabis should be standardized into one food source.
"There's no basis in medicine anywhere else for putting medicine inside a brownie, a cupcake, popcorn, sodas and gummy bears," Vandrey said.
Vandrey said the multiple food sources available now can confuse both the consumer and analytics. That's because test results for drug potency vary between foods.
Another issue with edible cannabis is its slow absorption. If a patient consumes a mislabeled product, it could take hours before it's known if he or she overdosed or needs more.
Taylor West, deputy director of the National Cannabis Industry Association, said individuals respond to different products so limiting the types of food sources for edibles could be unnecessary.
"I’m not really sure I see the rationale for putting severe limitations on the actual form of the product unless you can show that there’s some legitimate harm to doing it that way," West said.