There has been a drop in synthetic cannabis users seeking health services since a law change in July but professionals fear this won't last.
As of July 18, 2013, the sale of synthetic cannabis and party pill products in dairies, convenience and grocery stores, supermarkets, service stations and liquor outlets was banned. Any retailer wanting to sell the product had to apply for a licence.
Nine Western Bay companies have been granted licences to sell legal highs since the law change and two were under consideration.
A licence has also been granted for a wholesale company, and one licence application had been declined.
Health Board youth alcohol and other drug services clinician David Gilmour said since the worst offenders, such as the synthetic cannabis known as Kronic, were taken off shelves, there had been a reduction in psychotic episodes.