Prime Minister John Key has ruled out any animal testing on legal high products.
Parliament will pass legislation this week to pull all legal high products from shop shelves until they can be proved to be safe.
Mr Key had previously ruled out recreational drug testing on all animals except rats, he told Newstalk ZB.
"The advice I've had from the Health Department over the weekend, and having had discussions with Peter Dunne, is that they don't believe that that's safe.
"They say it has to be on two species, not one, so what I've said is, 'Okay, well if that's what you believe, then it's all out'."