Party pills will be tested on animals before they are allowed to be sold because "human safety is ... paramount", Associate Health Minister Peter Dunne says.
Under new regulations being proposed by the Government, companies that produce the psychoactive drugs will be made to prove they are safe.
Mr Dunne said the amount of testing on animals was still to be decided but he ruled out using "the controversial" lethal dose 50 per cent (LD50) test, where doses of a tested drug are increased to a sample group of animals until half of them dies.
"Human safety is the paramount consideration," Mr Dunne said in a statement today, responding to criticism from animal welfare groups and the Green Party that testing on animals, including dogs, was "barbaric".
The SPCA says it will condemn any plans to test party pills on animals, Newstalk ZB reports.
"To me, it's totally unnecessary to experiment on animals with party pills," SPCA national president Bob Kerridge said.
"There's absolutely no justification for it, no matter which way you look at it."
Mr Dunne said he had "a great deal of sympathy" for the view that it was sad to test legal highs on animals as opposed to testing necessary medicines.
"I understand that but I think we should see very different questions if we do not test these products and someone dies," he said.
Mr Dunne said the Ministry of Health was "actively working on finding alternatives to animal testing".
No decisions will be made without consulting with other ministries and ethics groups, Mr Dunne said.
He said criticism from the Greens about testing on animals was "ironic in the extreme".
"They need to take a long look at their own unrelenting pro-drug history," Mr Dunne said.