A law prohibiting the supply of psychoactive drugs in Northern Ireland is a milestone, Justice Minister David Ford said.
The Psychoactive Substances Act received royal assent last week and will be implemented from the spring.
It prohibits the production, supply and importation of these potentially dangerous drugs and will see offenders face up to seven years in prison.
Mr Ford said: “The Psychoactive Substances Act will considerably enhance the powers available to our enforcement agencies to stop those intent on supplying these harmful substances here in Northern Ireland and across the UK.
“The Act is an important milestone in the efforts of the Westminster Government and the devolved administrations and represents a significant change in approach to the emergence of these substances.”
The substances have been typically known as “legal highs”, but in most cases they had only remained lawful because there had been no scientific testing and advice leading to a ban.
In October, MPs claimed the legislation was being rushed. The Home Affairs Committee said ministers were not working properly with their own expert drug advisers.
Former senior coroner for Northern Ireland John Leckey likened a cluster of deaths of users to a serial killer on the loose. An estimated 20 people had died after taking stimulants known as “speckled cherries” or “speckled crosses”.
New psychoactive substances (NPS) are products chemically designed to mimic drugs that are already outlawed.
The law will create a blanket ban on all of them and their successors. These measures, based on a law from Ireland, will replace the current system of banning substances one at a time.
Serious concerns have been raised about the law’s effectiveness in the Republic.
Health Minister Simon Hamilton said the new law could save lives.
“My department, and the Department of Justice, have been working very closely with the Home Office on this issue and I believe this new legislation sends out a clear message - these substances are not legal and they certainly are not safe.”