Legal highs will be pulled from shelves within two weeks following an announcement from the Government this afternoon.

Each brand of synthetic high will undergo individual testing and will remain off the market until it is proven to be "low risk".

Protestors outside Special T Discounters on Cameron Road.

Associate Health Minister Peter Dunne says while there has been a substantial reduction in the number of synthetic cannabis products, reports of severe adverse reactions continue to be received by the National Poisons Centre and Centre for Adverse Reactions Monitoring, reports Fairfax Media.

"It has been impossible to attribute these adverse effects to any particular products and in the absence of that ministers accepted my recommendation at cabinet last Tuesday to end the transitional period, taking all products with interim approval off the market."

Peter will present to Parliament amended legislation putting the measure in place with it to be introduced and passed through all stages under urgency on May 8.

He says it will come into force the day after receiving the Royal Assent.

Under the bill, manufacturers will have to prove their products are safe before they are allowed back on the market.

Peter expects the new laws to be passed within the week, and for stock to be pulled off shelves almost immediately.