Pot Use and Green Tongues: The DUI Myth That Won’t Go Away

An urban legend about marijuana use and green tongues is circulating among some law enforcement communities and it’s getting innocent drivers thrown in jail.

The York Daily Record reports that a growing number of police affidavits in local DUI cases mention drivers displaying a ‘green tongue.’ It’s purportedly evidence of cannabis impairment, despite a complete lack of scientific evidence.

The York (Pa.) Daily Record/Sunday News analyzed more than 1,300 DUI cases that reached the York County Court of Common Pleas in 2018 and found at least 28 that mentioned phrases such as "green coating," "green film" and "green tint.”

“The science behind marijuana consumption turning your tongue green is about as sound as the science behind the earth being flat or that lying makes your nose grow,” Erik Altieri, executive director of NORML, told the publication in an email.

The myth may have California roots. Nick Morrow, who used to work for the Los Angeles County Sheriff’s Department and now testifies for the defense in these cases, says he thinks he knows where the lore originated. 

Morrow traces the green tongue back to a handbook called “Identifying the Marihuana User," which was published in 1986.

Dr. Forest Tennant Jr., the physician who wrote the guide, included a picture of a person with a green tongue in the handbook. He dedicated it to the California Highway Patrol.

The green tongue myth “just doesn’t seem to go away,” Morrow explained, even though there’s no truth to it. He said he’s only seen one green tongue in his entire career. It was on St. Patrick’s Day.

“The guy was drinking green beer and smoking weed.”

That'll do it.