Distributors of synthetic cannabis products say a decision to ban them will force alternative legal highs into the marketplace.
From Friday, the Misuse of Drugs Act will be amended allowing the Government to ban more than 40 synthetic cannabis products for the next 12 months.
Under the amendment, the Minister of Health can temporarily classify unregulated substances as a class C controlled drug, the same as cannabis.
Hemp Store manager Chris Fowlie, of Auckland, says manufacturers of synthetic cannabis will simply introduce new products to the market each time a ban is imposed.
