CCTV footage has been released showing legal high users stumbling around, falling over and collapsing unconscious on a busy high street in Newcastle.
Northumbria Police, the city council and ambulance chiefs set up a "New Psychoactive Substances" taskforce in January.
The number of call-outs by police involving legal highs has dropped by half, and by almost two-thirds to the ambulance service, in the first month the task force has been running.
The Police and Crime Commissioner Vera Baird said the issue was a "top priority" and explained the aim was to disrupt the sale of legal highs.
Work has included undercover test purchases, executing search warrants and warnings being issued to shops threatening prosecution if they continue to sell them.
There has also been educational work about the dangers of legal highs.
Head of resilience and special operations at North East Ambulance Service, Simon Swallow, said: "We are urging people not to take these so-called legal highs as they are putting their own lives in danger and also endangering the lives of others because these calls are potentially delaying our response to someone else who is suffering a heart attack or other life-threatening condition."
Additional reporting by Press Association
