Egil André Kvelstad Myhre from Namsos in Norway died the day after a party in March, but was only proven to have died as a result of the drug by a recently completed autopsy.
So-called synthetic marijuana is produced by spraying psychoactive chemicals onto plant matter that can then be smoked or eaten by users.
“One of the biggest problems with the new synthetic drugs is that we don't know what they contain or how strong they are,” Andreas Westin, Senior Physician at St. Olav's Hospital, told Norway's Aftenposten newspaper. "New drugs enter the market every week."
The use of synthetic marijuana is on the rise in the US, with the Center for Disease Control (CDC) reporting a threefold increase in deaths and poisonings related to the drug in the last year.
"A lot of these products are marketed as natural and safe and that could be the appeal," Royal Law, an epidemiologist with CDC's National Center for Environmental Health, told CBS News.
No deaths related to smoking too much ordinary marijuana have ever been recorded in Norway, as the effect of the drug does not increase beyond a certain point.
“With synthetic cannabis, the more you take, the larger the effect. You can get cramps and there is a risk for heart attack,” Liliana Bachs at the Norwegian institute of public health told broadcaster NRK.
Use of synthetic marijuana is increasing in Norway, with most users ordering online.
"We seize new psychoactive substances and 'look-alikes' every day, Alf Røgeberg, from Norway's border control authority, told Aftenposten. ”Drug use is increasing, that's clear.”
At least thirty people have died in Norway due to other synthetic drugs. Most of the deaths are related to PMMA, a chemical drug designed to simulate the effects of ecstasy or MDMA.
“Norway has a sad world record with that substance,” Westin told Aftenposten.
The drug is potentially more dangerous than ecstasy, and many drug users are sold PMMA thinking it is MDMA or ecstasy.
“PMMA takes longer to have an effect, so people could take a tablet and think it wasn't working and then take more,” Harry Shapiro of the charity Drugscope told the BBC. “Having taken more, you're dealing with a drug that's far more toxic than ecstasy.”