Police are warning the public about the dangers of taking the drugs formerly known as 'legal highs' after six people ended up ill in hospital after taking them.
They are all believed to have suffered an adverse reaction to a bad batch of New Psychoactive Substances (NPS), which used to be known as legal highs.
None of those taken ill are thought to be in a life-threatening condition, but they were kept in overnight as a precaution.
It is believed all those involved have taken similar types of NPS that were bought in the Hippy Green area of Newcastle.
They include substances known as Spice, Killer Smeg and Spongebob.
Officers are urging anyone who is in possession of the substances to hand them in to police to avoid putting themselves or other members of the public at risk.
Chief Inspector Barrie Joisce said: "So far we have not received any reports of a life-threatening reaction to these drugs, but we are concerned that people could be putting themselves at risk.
"Here in Northumbria we have done a lot of work warning people about the dangers of legal highs, and they were recently banned under new legislation brought in earlier this year.
"However, our priority is the safety of the public, and we want to make sure that any substances that may cause harm to those using them should be taken off the streets.
"If you have drugs of this nature in your possession, or have any information about who may be distributing them, then contact police immediately."