Basel has become the first city in Switzerland to receive approval for a recreational cannabis pilot scheme, set to launch this northern hemisphere summer.
Under the government-approved plan, around 400 people aged over 18 will be permitted to purchase cannabis at selected pharmacies, with their consumption patterns and physical and mental health closely monitored over a 30-month period.
The cannabis will be supplied by Swiss firm Pure Production, which has been granted an exemption for research purposes.
The scheme is the first to be authorised since Switzerland sanctioned time-limited pilot projects in May last year.
The Federal Office of Public Health (FOPH) said the aim was to improve understanding of "alternative regulatory forms", such as regulated sales at pharmacies, that could form the basis of future legislation.
Growing, importing, producing and selling cannabis remain banned in Switzerland, although the FOPH acknowledged there is a thriving illegal market and majority public support for reform.
It warned that participants who pass on cannabis from the pilot projects to others will be penalised, with repeat offenders removed from the programs altogether.