Newcastle police are investigating the spread of a dangerous new drug that caused a mass overdose on the weekend.

At least 11 party goers were taken to Calvary Mater Newcastle and John Hunter Hospital emergency departments between Friday and Monday nights after taking 'blue superman' pills.

One of the 'blue superman' pills that were responsible for 11 people being taken to Newcastle hospitals on the weekend.

The distinctive blue triangle-shaped pills have a superman logo stamped on them and are being sold as MDMA, or ecstasy, in Newcastle, but may not contain any MDMA.

The patients, ten men and one woman, were aged between 18 and 34. They presented over four nights and were not believed to have attended the same venue.