The ban on drugs like ecstasy and crystal meth is back in force.
President Higgins signed emergency legislation yesterday evening, which brought the new law into effect at midnight.
The ban on over 200 psychoactive drugs was overturned on Tuesday, when the Court of Appeal struck down part of the law as unconstitutional.
The government was forced to pass emergency legislation through the Dáil and Seanad - after the Court of Appeal struck down a section of the Misuse of Drugs Act.
The amended bill once again bans ecstasy, ketamine, crystal meth and other psychoactives.
Agriculture Minister Simon Coveney said the government did all it could to minimise the length of time the drugs would be legalised.
Health Minister Leo Varadkar has said in future, the Oireachtas will have to approve new restrictions whenever the government wants to ban individual drugs.
"Primary legislation will now be needed to add to this controlled substances, until we have new primary legislation to cover the policies and principles," he said.
"Having said that though the criminal justice psychoactive substances act of 2010 does still stand," he added.
It comes as the State withdrew charges against a man accused of holding a small amount of ecstasy in light of the ruling.