Kiwis are warned to watch out and get their drugs tested after "winter's first dodgy pill" was found.
The pill is described as a 'purple Papa de Papel' and was first seen in the North Island in May.
Sold as MDMA, it weighs 485mg and contains around 203mg of eutylone.
KnowYourStuffNZ, which runs free drug-checking services, posted a message to Facebook after it was discovered.
"This one's approximately two doses of eutylone being sold as MDMA. Don't forget to check the pill library to see if there's anything you recognise," it wrote.
"We've got clinics happening up and down the country in the few weeks, so check the events page to see when we're in your neck of the woods."
Eutylone is a stimulant that's "much more dangerous" than MDMA and can cause severe and adverse reactions.
Risks from eutylone include anxiety, headaches, stomach upsets, agitation, and paranoia, with the worst outcomes being vomiting, convulsions, and possibly death.
Often, eutylone feels like the user has taken MDMA but after an hour or so the euphoria fades.
"Users thinking they have MDMA may think it is just weak MDMA and be tempted to take more. Higher doses have been linked with intense, unpleasant and potentially dangerous experiences," KnowYourStuffNZ says on its website.
According to KnowYourStuffNZ, users have reported effects at 35mg. At an MDMA-sized dose (typically 100mg), then they risk taking a dangerous amount of eutylone.
One KnowYourStuffNZ client who took a total of 250mg reported feeling "poisoned" and spent 48 miserable hours unable to sleep.
It's been linked to several hospitalisations with some people still feeling unwell up to 10 days later.
