The Government wants to restrict the manufacture and sale of mock cannabis cigarettes, but must wait for a law change first.
The products - currently on sale at party-pill shops and dairies, with no age or other restrictions on their purchase - contain vegetable matter sprayed with naptholindole, which when smoked produces similiar psychoactive effects to cannabis.
Associate Health Minister Peter Dunne says legislation due to be passed in the next couple of months will make it possible to restrict the products.
But a new law is needed, he says, so that rather than individual products being targeted, their generic ingredients can be restricted or banned.
Mr Dunne says he's interested in a British proposal to ban such ingredients: "I think that's the long-term way to go."
Chris Fowlie, who manages the Hemp Store in Auckland, says his shop acts responsibly.
However, he says, many others do not, so an age limit may be necessary to prevent the products from being banned altogether.