"Our study indicates that the opening of North America's first supervised injection facility was not associated with measurable negative changes in the use of injected drugs. Indeed, we found a substantial reduction in the starting of binge drug use after the opening of the facility, suggesting that it had not prompted 'risk compensation' among local injecting drug users, whereby the benefits of a safer environment are overcome by more risky behaviours such as higher intensity drug use."

Source

Kerr, Thomas, Jo-Anne Stoltz, Mark Tyndall, Kathy Li, Ruth Zhang, Julio Montaner, Evan Wood, "Impact of a medically supervised safer injection facility on community drug use patterns: a before and after study," British Medical Journal, Vol. 332, Jan. 28, 2006, pp. 221-222.