Drugs sold online are readily available for shipping to Sweden. A former user, who Swedish Radio calls Martin, explains the procedure.
"It is easy, not hard at all," he says. "You go in, type where you live and pay in advance using Internet money or a bank card. In three or four days, the stuff arrives."
Traces of a new drug, 5-IT, have been found in the autopsies of 14 young people here this year. In two cases, the 5-IT was found to be the direct cause of death.
The most dangerous aspect of this new drug, says Martin, is that nobody knows quite how it works. Advice is mostly available on amateur Internet forums.
And so far, 5-IT is legal in Sweden. That means there are no legal obstacles to buying it online and having it shipped right to your doorstep.
According to Lars Hansson, the Swedish customs' drugs expert, packages containing online drugs are usually clearly marked.
"As long as a substance is legal, the seller wants to let the customer know what is in the package," Hansson says.
But it is going to be harder for 5-IT to cross Swedish border. The drug will remain legal but the Customs authorities will have the power to seize and destroy 5-IT when it arrives here.
That is thanks to a new law, introduced last year, which for public health reasons allows Customs to destroy substances that have yet to be classified as narcotics.
Lars Hansson thinks the law has saved lives, but also says that the customs service will never be able to stop all the harmful substances that enter Sweden.
"Around 250,000 packages arrive at Stockholm's Arlanda airport every day, it's like a flood," Hansson told Swedish Radio.
"Customs are following the government's instructions to prioritize finding drugs sold online. But preventing deaths is also about spreading awareness and, in the end, about everyone approaching drugs responsibly."
The former user Martin says the new law has led to more seizures by customs, but he agrees that spreading knowledge about drugs is the most important means of prevention.