Medical marijuana is currently legal in 29 states in the U.S., and the District of Columbia, and a growing body of research supports the potential health benefits of cannabidiol (CBD) to help treat some conditions such as epilepsy, anxiety and chronic pain.

Cannabidiol is a chemical that naturally occurs in the cannabis plant. Unlike marijuana’s other popular active ingredient, THC, cannabidiol is not known to be addictive or offer users a “high.”

But because marijuana use is illegal under federal law, there is no regulation or oversight for online sales of cannabis products.

A research team from the University of Pennsylvania found that nearly 70 percent of CBD products sold online are either over- or under-labeled.

The team, led by Marcel Bonn-Miller, adjunct assistant professor of psychology in psychiatry, spent a month searching and identifying CBD products available for online retail purchase that included CBD content on the packaging.

They purchased 84 commercially available CBD products from 31 different companies, and sent all samples to an independent lab that analyzed each of the product’s ingredients using high-performance liquid chromatography.

The results showed that nearly 31 percent of the products had what the researchers considered an accurate amount of CBD in relation to what was advertised on the product label.

“Accurate” for the study referred to the CBD content being within 10 percent of the amount advertised.

However, 42 percent of the products were under-labeled, and 26 percent had more CBD than what was printed on the label.

The findings suggest that patients who are purchasing CBD products to help alleviate symptoms of various conditions may be buying products that are either ineffective, or consuming a higher dose than needed.

The researchers also discovered that accurate labeling varied based on product type. For example, vaping liquid containing CBD was mislabeled most frequently, at 90 percent. About half of extract oils were inaccurately labeled, and tinctures, or alcoholic extracts, were equally likely to be over-, under-, or accurately labeled. 

Bonn-Miller believes the rampant mislabeling among CBD products is a direct result of inadequate regulation or oversight over these products.

“The big problem, with this being something that is not federally legal, is that the needed quality assurance oversight from the Food and Drug Administration is not available. There are currently no standards for producing, testing, or labeling these oils,” Bonn-Miller said.

Business estimates show that the market for CBD products could grow to more than $2 billion in consumer sales by 2020, demonstrating that the mislabeling issue may only get worse.

Another worrisome finding showed that 18 of the products also contained THC, the ingredient in cannabis that causes users to feel high.

Patients intending to use CBD products for medicinal purposes may unknowingly ingest THC, which could cause adverse effects like cognitive impairment. This is a potentially significant threat for parents who give their children CBD to treat conditions like epilepsy.

Bonn-Miller’s previous research investigating label accuracy of edible medical cannabis produced similar results.

“People are using this as medicine for many conditions (anxiety, inflammation, pain, epilepsy),” Bonn-Miller explained. “The biggest implication is that many of these patients may not be getting the proper dosage – they’re either not getting enough for it to be effective or they’re getting too much.”

The study, published this week in JAMA, came out just days after the FDA issued warning letters to four companies selling products containing CBD and illegally claiming the products prevent, diagnose, treat or cure cancer – without any sufficient evidence to back up the claims.

The companies – Greenroads Health, Natural Alchemist, That’s Natural! Marketing and Consulting, and Stanley Brothers Social Enterprises LLC – marketed products with claims that they could prevent or reverse cancer, or could kill cancer cells and tumors. Some of the products were also advertised as beneficial alternatives for Alzheimer’s and other diseases.

“We don’t let companies market products that deliberately prey on sick people with baseless claims that their substance can shrink or cure cancer and we’re not going to look the other way on enforcing these principles when it comes to marijuana-containing products,” said FDA Commissioner Scott Gottlieb, M.D., in a statement.

“We recognize that there’s interest in developing therapies from marijuana and its components, but the safest way for this to occur is through the drug approval process – not through unsubstantiated claims made on a website. We support sound, scientifically-based research using components derived from marijuana, and we’ll continue to work with product developers who are interested in bringing safe, effective, and quality products to market.”