This study, published in Drug and Alcohol Dependence, from researchers at the Milken Institute School of Public Health at George Washington University and the Center for Public Health Law Research used mystery shoppers to assess 130 cannabis retail practices in summer 2025 in five U.S. cities (Los Angeles, California; Las Vegas, Nevada; Denver, Colorado; Portland, Oregon; and Seattle, Washington) regulating legal nonmedical cannabis retail. 

The study finds that cannabis retailers in the five cities frequently made prohibited health claims and minimized risks, reinforcing public health concerns and the need for ongoing cannabis retail surveillance and stronger regulatory oversight and enforcement.