The legal-high industry says the Ministry of Health put retailers in a difficult situation by not telling them in advance it had banned five products after the reporting of harmful side-effects.
It says retailers were not formally told until after the ban came into force at 2pm on Monday. It is illegal to sell these products, possess or consume them.
The ministry has revoked the licence for the brands - AK47, Anarchy, Karma, Northern Lights Primo and Voodoo - following an increase in calls to the National Poisons Centre.
Associate Minister of Health Todd McClay says acute nausea and vomiting, acute anxiety episodes and prolonged withdrawal symptoms were among the side-effects reported and the five brands contain the same or a similar active ingredient.
Mr McClay says the recall is a sign that the Psychoactive Substances Act is working well.
The Star Trust, which represents most of New Zealand's legal-high companies, says the industry found out about through the media - and that's not good enough.
Spokesperson Grant Hall says the trust has advised them to take the products off shelves - even if they have yet to be formally notified by the ministry.
Twenty-three enforcement officers have also been appointed to make sure that retailers are sticking to the law.