The DHB did not record synthetic cannabis presentations separately.
The Psychoactive Substances Act, which passed in 2013, regulated the availability of substances but allowed some products to stay on the market.
The Psychoactive Substances Amendment Bill, passed in May last year, ended that interim product approval.
Tommy Wilson, director of Te Tuinga Whanau Support services, said there should not be separate rules for different substances in society.
"It's gone under ground and because it has we don't have any way of monitoring it - some of the stuff going into the synthetic highs is just toxic, it's terrible.
"That is why people are spinning out and you are getting all this psychosis and nutters. It's not just from P now, we have created another sort of P with what they are putting into synthetics.
"If you legalise stuff you have the opportunity to know what's in it. Now we have no idea."
But Get Smart Tauranga manager Stuart Caldwell said it was a huge relief when the Government finally passed the law banning legal highs.
"Every week while they were available we would have distraught mothers calling us, usually about their teenage sons, but since the ban we haven't really seen an increase in other drug related presentations."
Mr Caldwell said there was apparently a black market still running with some synthetics and thought it would have been fuelled by people who stockpiled the substance prior to the ban.
Hanmer Clinic chief executive David Benton said there was definitely synthetic cannabis still available, despite the product being made illegal.
If people really wanted it, they could still get supplies, he added.
The drug
* Synthetic cannabinoids are smokable products containing varieties of plant matter that have been infused with synthetic cannabinomimetic substances. They act in a similar way to cannabinoids naturally found in cannabis such as tetrahydrocannabinol (THC).
* Dependence - There is limited evidence around the dependence, addiction and overdose risk from synthetic cannabinoid use. However, as with cannabis, it is very likely that dependence is a real risk for users.
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