Cumbria detective's legal high 'Russian Roulette' warning
People taking legal highs are "playing Russian Roulette with their lives", a senior Cumbria detective said.
Fifteen Cumbrian addresses were searched during a week-long crackdown on the substances.
Eight people were arrested and bailed and hundreds of pounds of what are believed to be controlled drugs and more than £5,000 cash was seized.
Det Ch Insp Rob O'Connor said there was a misconception about legal highs and many contained controlled drugs.
Cumbria Police took action as part of Operation Burdock, a national crackdown on legal highs.
Forensic tests will be carried out on the substances seized during the operation.
Mr O'Connor, who led the operation, said a lot of the work had been about education.
He said: "There's a real misconception, certainly amongst young teenagers, that because these drugs are advertised as being legal highs and they can buy them off the internet or in what we would call head shops they think it's perfectly legal and safe to do so and that sadly couldn't be further from the truth."