Testing is underway on samples of synthetic cannabis products which went on the market on Friday to replace the legal high known as K2.
Associate Health Minister Peter Dunne says he has instructed officials to buy samples for testing as soon as they appear in shops.
A ban on K2 was put in place in November last year and came into effect on Friday but new products have already taken its place.
Mr Dunne said it's a cat-and-mouse game the Government will play until the Psychoactive Substances Bill is passed into law in August this year requiring manufacturers to prove their products are safe before they can be sold.
The minister said no one can have any confidence in the integrity of those behind the products, because the industry has demonstrated it has not the slightest interest in the health and well-being of those who use them.