By Amanda MacMillan for Time

“The first step is ordering products from reputable sources or getting advice from other people you trust,” he says, “or getting products tested yourself in an independent lab.” (The group Patient Focused Certification can provide names of nearby facilities that will test CBD extracts, he says.) “Unfortunately, the onus is on the consumer to do the homework.” - Marcel Bonn-Miller, PhD

Many people buy medical marijuana online — but they may not always get exactly what they pay for, according to new research.

A study, published this week in JAMA, found that nearly 70% of all products sold online made from cannabidiol — an extract of the marijuana plant also known as CBD — contained either higher or lower concentrations of the drug than indicated on the label. That could potentially mean those CBD products are ineffective or even dangerous.

Some CBD products examined in the study also contained significant amounts of THC, the chemical compound in cannabis that makes people feel high. Pure CBD should not contain THC, which is one reason experts say it has potential as a medical treatment, and is not something that can be abused. The presence of THC is especially concerning because CBD is sometimes used by children with seizure disorders, says lead author Marcel Bonn-Miller, PhD, adjunct assistant professor of psychology in psychiatry at the University of Pennsylvania.

“Parents could be giving their kids THC without knowing it,” says Bonn-Miller.

For the study, Bonn-Miller and his colleagues spent a month searching the Internet and purchasing 84 products, from 31 different companies, that included CBD content on their packaging. Then they analyzed each product for actual CBD content, as well as other ingredients.

They found that 42% of the products were under-labeled, meaning they contained a higher concentration of CBD than indicated. Another 26% were over-labeled, while 30% contained accurate CBD content (within 10% of the amount listed).

No studies have shown that taking too much CBD is harmful, says Bonn-Miller, although very little research has been done on doses over 1,500 mg. A bigger concern, he says, is that doses that are too low may affect how well the product works. Because of the variability between products, it can also be difficult for patients to expect consistent results.

“Say I have a kid with seizures who’s in really bad shape, and I ordered some CBD oil as a last-ditch attempt to treat them,” he says. “If I happened to order something that has hardly any CBD in it, that’s a problem. Number one, I might not be getting any therapeutic effect, and number two I’m probably spending a decent amount of money for CBD that I’m not actually getting.”

CBD products sold in liquid form—for use with vaping devices—were mislabeled about 88% of the time, while CBT oils were mislabeled about 55% of the time. THC was detected in 18 of the 84 samples tested, and in some cases it was found in concentrations that “may be sufficient to produce intoxication or impairment, especially among children,” the authors wrote in their paper.

A 2015 study by the same group of researchers found similar mislabeling among edible marijuana samples. But the mislabeling of CBD products is even more concerning, says Bonn-Miller, since CBD is largely used for medicinal purposes among people of all ages, rather than as a recreational drug.

The researchers believe the reason for these inconsistencies is a lack of regulation from the Food and Drug Administration (FDA). The federal government considers cannabis a Schedule 1 controlled dangerous substance, and is not involved in production, labeling and distribution at the state level.

“Right now, if you buy a Hershey bar, you know it has been checked over; you know how many calories are in it, you know it has chocolate as an ingredient, you know how much chocolate is in there,” Bonn-Miller says. “It’s crazy to have less oversight and information about a product being widely used for medicinal purposes, especially in very ill children, than a Hershey bar.”

Last year, the Hemp Business Journal estimated that consumers will spend more than $2 billion a year on CBD products by 2020. One drug company, GW Pharmaceuticals, is currently pursuing FDA approval on a CBD-based treatment for children with a rare form of epilepsy — but beyond that, the industry remains unregulated, and Bonn-Miller warns consumers should be wary of what they’re purchasing online.

“The first step is ordering products from reputable sources or getting advice from other people you trust,” he says, “or getting products tested yourself in an independent lab.” (The group Patient Focused Certification can provide names of nearby facilities that will test CBD extracts, he says.) “Unfortunately, the onus is on the consumer to do the homework.”

Tweet