One in five Americans experiences chronic pain — a distressing reality that drives depression and opioid use. This widespread pain problem is sending people to medical cannabis dispensaries in droves, looking for relief.

But according to a new study, which reviewed 8,505 cannabis products sold by 653 dispensaries across the United States, tetrahydrocannabinol, or THC, concentrations are often twice or even three times TOO HIGH FOR PAIN RELIEF.

THC is the main psychoactive compound in marijuana, and high concentrations can create a “vicious cycle” of dependence, according to the study authors. Too much THC cause a person to develop tolerance to the drug’s effects and can induce adverse mental health effects with potentially lasting consequences.

The findings were published Thursday in the journal PLOS ONE.

“The products offered online in dispensaries, which should be a reflection of what they have in their physical facilities, are mostly very potent and represent a risk for patients that seek medicinal effects, and also a risk for regular users in the long run,” co-author Edgar Alfonso Romero-Sandoval, a researcher at Wake Forest Medicine, tells Inverse. [Read more at Inverse]