After a 12-year ban that was completely ineffective in stopping the manufacture of methamphetamine, the government is going to allow pseudoephedrine products to be sold over the counter again.

Rejoicing for the sinus sufferers and soldier-on types, but a nervous time for pharmacists as the demonised ingredient in effective cold medicines, pseudoephedrine, is allowed back in chemist shops.

In 2009 the then-Prime Minister John Key declared war on methamphetamine with a plan to ban over the counter sales of cold and flu drugs containing pseudoephedrine.

Those were the days when ram raids and armed hold-ups were aimed at chemist shops, the perpetrators looking for the main ingredient used to cook up methamphetamine.

The ban came into force two years later with the reclassification of pseudoephedrine as a Class B2 prescription-only drug.

Key said at the time he was worried about his teenage children getting involved with methamphetamine, or P, and in an interview with Paul Holmes he said his own home was robbed by a man with a P habit.

"It is a $1.5 billion problem, it is wrecking lives, and it is wrecking families," Key said. "It is something ... as a parent I can tell you, obviously you worry about your children," he said.

The ban ended the ram raids and burglaries on pharmacies but it did not stop crime associated with P. The gang-run imported methamphetamine market is thriving and it is still wrecking lives and wrecking families.

But soon people will be able to buy cold and flu medicines containing pseudoephedrine over the counter again, under a new ACT policy it got over the line during coalition negotiations.

"Since 2011, New Zealanders haven't been able to find over the counter cold and flu medicine that actually helps," leader David Seymour said. "Pseudoephedrine was banned because of fears it would be used for P production and following assurances there would be alternatives. Instead, the evidence shows that gangs continue to produce P, and there are no viable alternatives for people who are unwell."

Pharmacists worry that the change will make them a target of criminals again.

Associate professor at the National Addiction Centre, University of Otago, Simon Adamson says his first reaction was as a customer wanting cold and flu medicine that works.

He says the methamphetamine market has moved on from the clandestine meth laboratories that were prevalent when Key's government bought in a P fighting plan, but it is too soon to say if the move will make chemists vulnerable to crime…

Go to this episode on rnz.co.nz for more details