The effect of taking fentanyl is the same as taking heroin, but the side effects can be great and an overdose can lead to death in the worst case.
With the help of the kit, the user can detect if their drugs are contaminated by the controlled substance before it is too late.
–We want to make it as safe as possible for the users, says Robert Sanderö.
"No fentanyl in my tjack, please"
The association has received positive feedback on the initiative.
"We have received messages: 'Thank you, you saved my life'," says Robert Sanderö.
The Twitter page "Drug warnings", which is run by the Users' Association's Stockholm department, warns of dangerous substances that are in circulation on the Swedish drug market.
In a post that the page has retweeted, a user writes:
"It's cool to be careful! No fentanyl in my tjack, please" and posting a picture of a negative fentanyl test.
Hear Robert talk about when he took a fentanyl overdose and see how a self-test for the substance works in the clip above.