By Pat Anson, PNN Editor

If you use cannabis for pain relief or take melatonin to help you sleep at night, you may want to check the label and ask the manufacturer just how accurate the list of ingredients is.  Or think twice before buying it.

Two more studies are raising doubts about the accuracy of label claims on cannabis products and melatonin supplements, which are often marketed with unsupported claims about their health benefits.

In the first study, published this week in JAMA, researchers analyzed 25 melatonin gummy products, including 5 gummies that also contained cannabidiol (CBD). Melatonin is a natural hormone produced by the brain at night to help induce sleep. Supplements containing synthetic melatonin and/or CBD are often marketed as products that improve sleep, reduce anxiety, and promote relaxation.

Researchers found that only 3 of the 25 gummies contained enough melatonin to be within 10% of the labeled amount – with one product containing 347% more melatonin than what was listed, a potentially dangerous amount. Another gummy contained no melatonin at all, just CBD.

“The great majority of melatonin gummy products were inaccurately labeled, with most products exceeding the declared amount of melatonin and CBD,” wrote lead author Pieter Cohen, MD, an associate professor at Harvard Medical School and an internist at Cambridge Health Alliance. “Given these findings, clinicians should advise parents that pediatric use of melatonin gummies may result in ingestion of unpredictable quantities of melatonin and CBD.”

Pediatric use is concerning because calls to U.S. Poison Control Centers about children ingesting melatonin have increased five-fold over the past decade, resulting in nearly 28,000 emergency room visits, over 4,000 hospitalizations and two deaths.

Researchers say it takes just 0.1 mg to 0.3 mg of melatonin to increase plasma levels beyond the normal nighttime range in young adults. The amount of melatonin found in the gummies was much higher, including one product containing 13.1 mg of melatonin.

“Consuming melatonin gummies as directed could expose children to between 40 and 130 times higher quantities of melatonin,” they said. “With respect to CBD, the drug is FDA approved to treat refractory seizures caused by 3 rare genetic disorders, but the FDA has not approved the use of CBD for any indication in healthy children.”

The JAMA report is believed to be the first U.S. study to quantify the amount of melatonin in over-the-counter supplements. A 2017 Canadian analysis of melatonin products had similar findings, with the actual dose of melatonin ranging from 17% to 478% of the amount listed on the label. Neither the U.S. or Canadian studies identified the melatonin brands that were tested.

Too Little THC

It wasn’t too much, but too little tetrahydrocannabinol (THC) that University of Northern Colorado researchers found in 23 cannabis flower products purchased at state-licensed dispensaries. The study findings, recently published in the journal PLOS One, show that nearly 70% of the flower samples had THC levels at least 15% lower than what was listed on their labels.

Inaccurate labeling has long been a problem in the cannabis industry. Some growers and merchants resort to “lab shopping” to seek out product testing laboratories that generate the most desirable results – which means inflated levels of THC.  There’s a financial incentive to do so, because cannabis products containing high amounts of THC usually sell at a higher price.

One of the flower samples, purchased at a Denver dispensary and sold under the brand name “OG Kush 2,” had only half the amount of THC listed on its label.  

“Given our results it is urgent that steps are taken to increase label accuracy of Cannabis being sold to the public. The lack of accurate reporting of THC potency can have impacts on medical patients controlling dosage, recreational consumers expecting an effect aligned with price, and trust in the industry as a whole,” researchers said.

“Although we have no power to change the current system, we hope highlighting this issue and educating consumers will affect the change needed to remedy inflated potency of flower products. Addressing this discrepancy will require both changes to the regulatory system and consumer awareness that reported THC potencies are frequently inflated.”

Although 38 states and Washington DC have legalized medical or recreational cannabis, there is little consistency in labeling, regulating or testing cannabis. The researchers called for more regulatory oversight of cannabis and standardized testing protocols.