Northland legal-high opponents are questioning why the new ban took so long and want to ensure there will be support services available for those addicted to the substances.
Northland District Health Board says it is too early to say what services may be needed to deal with any withdrawal fallout from the legal high ban.
"We will be watching the situation closely to ensure that if people do require assistance they can access it," said NDHB general manager of Maori health and mental health and addiction services Kim Tito.
Mr Tito said the alcohol and drug helpline, offering free confidential information, insight and support on such issues, could be accessed through www.alcoholdrughelp.org.nz or 0800 787 797.
But Kevin Carroll, who owns The Same Name store in Whangarei's Cameron St Mall - and four others nationwide - that sell tobacco products and legal highs, said the ban would send the products underground and into the hands of "the illicit drug trade".
After months of saying psychoactive substances could not be banned, Associate Health Minister Peter Dunne did a U-turn and announced on Sunday that all psychoactive substances - also known as legal highs - would be pulled from sale in two weeks once legislation can pass in Parliament.
More than 250 products were banned in August when the Psychoactive Substances Act, promoted by Mr Dunne, came into force. But 41 products had temporary approval for sale until a testing regime was introduced.
Mr Dunne said the remaining products would be stripped from shelves until they could be assessed by a Ministry of Health-backed testing regime.
Mr Carroll said retailers were "dealt the short straw" in the whole process and, after being told they could sell legal highs, had suddenly "had the rug pulled from under us".
He said the products would now go underground and be at the mercy of the illicit drug trade.
The ministerial U-turn came amid widespread public opposition to the products, with marches and rallies held across the country, including in Whangarei. Darcel Bolton, from the "Ban Synthetic Cannabinoids Whangarei" was delighted that the products would be removed from the shelves, saying they should never have been allowed in the first place.
She suspects that "politics" in an election year were behind the about face.
"A big concern though is what happens after they are pulled off for those people addicted.
"Will there be more support services and counsellors available for those people?" Ms Bolton said.
Her organisation has set up a Whangarei support group for users, ex-users, family members and friends of users, which has its first meeting on May 1 from 5.30pm at Otangarei Community House.
The group is believed to be the first of its kind in the region and Ms Bolton said she hoped Mr Dunne would provide a counsellor trained in legal high addiction to speak to the support group.
Whangarei District Council currently plans to restrict where legal highs can be sold in the central city to Lower Cameron St, Clyde St and Albert St through a locally approved products policy (LAPP) that has gone out for public submissions.
Mayor Sheryl Mai welcomed the ban and said plans for the LAPP would continue as, if products were given approval to be sold in the future, local authorities would still need to limit where they could be sold.
A Northland police spokesperson said police had been working with the community to mitigate any possible harm caused by the sale of legal highs.
"The introduction of the Psychoactive Substances Act in 2013 helped us address several concerns, including the risk to health, involvement by vulnerable young persons, addiction and crime problems to support habits," the spokesperson said.