A blanket ban on so-called legal highs and tough new enforcement powers will come into effect on 26 May 2016.
The Psychoactive Substances Act will protect young people by banning any production, supply and importation or exportation for human consumption of these potentially dangerous drugs, linked to the deaths of 144 people in the UK in 2014 alone.
The act provides a range of criminal and civil sanctions including new powers for police and tough sentences of up to 7 years for offenders.
The UK will be the first country in the world to put in place a rigorous system of testing to demonstrate that a substance is capable of having a psychoactive effect, providing evidence to support civil action and prosecutions.
Minister for Preventing Abuse, Exploitation and Crime Karen Bradley said:
Psychoactive substances shatter lives and we owe it to all those who have lost loved ones to do everything we can to eradicate this abhorrent trade.
This act will bring to an end the open sale on our high streets of these potentially harmful drugs and deliver new powers for law enforcement to tackle this issue at every level in communities, at our borders, on UK websites and in our prisons.
The message is clear so-called legal highs are not safe. This act will ban their sale and ensure unscrupulous traders who profit from them face up to 7 years in prison.
Sanctions under the act include:
up to 7 years in prison for the supply, production, possession with intent to supply, importation or exportation of a psychoactive substance for human consumption
up to 2 years in prison for possessing a psychoactive substance in a custodial institution
prohibition and premises orders, which will allow police to shut down head shops and online dealers in the UK, with up to 2 years in prison for those who fail to comply
police powers to seize and destroy psychoactive substances, search people, premises and vehicles, and to search premises by warrant if necessary
The government has already taken action against so-called legal highs, having banned more than 500 potentially dangerous drugs since 2010 under the Misuse of Drugs Act 1971.
The new act will go even further but legislation alone is not enough. The government continues to take action across prevention, treatment and recovery to reduce harmful drug use and is working with experts - including the Advisory Council on the Misuse of Drugs - to develop a new drugs strategy.