An analysis of 75 edible marijuana products sold to patients in Seattle, San Francisco and Los Angeles found that labels on just 17 percent accurately described their levels of THC, the main psychoactive ingredient, researchers reported Tuesday.

Sixty percent of the products had less THC than their packages advertised, while 23 percent of them had more THC than claimed.

“We need a more accurate picture of what’s being offered to patients,” said Dr. Donald Abrams, the chief of hematology and oncology at San Francisco General Hospital, who was not involved in the new study, which was published in JAMA, The Journal of the American Medical Association.

“What we have now in this country is an unregulated medical marijuana industry, due to conflicts between state and federal laws,” Dr. Abrams said. [Read more at The New York Times]