A new ad campaign warns teenagers in Colorado about the long-term effects of marijuana use. The “Don’t Be a Lab Rat” campaign targets 12- to 15-year-olds, Reuters reports.

The ads state that the long-term effects of marijuana are not yet fully understood, and warn teens that if they use marijuana they are essentially volunteering as subjects of research about the drug’s effects. In Colorado and Washington state, the possession and recreational use of small amounts of marijuana is legal for those 21 and older.

The ads will air on television, online and in movie theaters, the article notes. The Colorado Department of Health and Environment will also set up life-size “Lab Rat Cages” at middle schools and high schools, concert venues, skate parks and other locations that teens frequently visit.

“While much still needs to be learned about the effect marijuana has on the brain, enough information is available to cause concern in terms of the negative effects marijuana can have on the developing brains of teenagers,” Dr. Larry Wolk, the department’s executive director and chief medical officer, said in a news release. “The core premise of the ‘Don’t Be a Lab Rat’ campaign acknowledges that more research is necessary, but it also poses the question of whether or not teens should risk the potential negative effects of using marijuana.”

Colorado Governor John Hickenlooper noted a recent survey found the percentage of high school students who think using marijuana poses risks for their health has decreased. “We have a civic and public health obligation to do everything we can to make our children aware that there are risks for teens when they use marijuana,” he said. “This campaign is designed to grab the attention of teens and their parents, and provide them with the facts to have an informed discussion and make informed choices.”