Mr Cull was commenting after Associate Health Minister Peter Dunne late yesterday announced legislation to remove all remaining so-called ''legal highs'' from sale would be introduced to the House on May 8.
The legislation was expected to be passed under urgency the same day and would come into force days later.
Mr Cull said the move was in line with the public's view that legal highs should be banned, not controlled, and it was ''better late than never''.
However, it also begged the question, as the Government had until now maintained it was not possible to simply ban the products and had instead ''abdicated responsibility'' to local governments to control them, he said.
''Up until now, we've been consistently told by the Government and Minister Dunne that it wasn't possible.
''I think it's good that it would appear the Government has found a way to provide what the public and various communities have been asking for.''
Toxicologist Dr Leo Schep, of the National Poisons Centre, in Dunedin, also welcomed the Government's move as an important step to protect young people.
However, he was also ''surprised it's taken that long'', given the ''groundswell'' of public concern at the impact legal highs were having on people's short- and long-term health, he said.
People trying to quit were having ''pronounced'' adverse effects, including ''severe, persistent vomiting to the point of blood'', and he was ''worried - really worried - about the long-term effects of these drugs''.
''The emerging chronic effects are what seriously concern me, and we're only just starting to see them now. For some people, that could be permanent health issues.''
Mr Cull said he had also heard numerous stories about the ''horrendous'' effects of legal highs.
The country had found itself in the ''ridiculous'' situation where a legal substance was more dangerous than cannabis, the illegal drug it had replaced for some.
While ''pleased a way forward appears to have been found'', Mr Cull also worried other products could yet emerge, or some users would find other, more harmful, ways to get high.
For that reason, Mr Cull said he supported reconsidering the legal status of cannabis, if it led to a better approach to minimising harm.
However, with more evidence of cannabis' impact on young people also emerging, Mr Cull stressed he had come to no conclusions about the merits of decriminalisation.
''We should be taking a broader view of all mind-altering substances and coming up with a sensible regime.''
However, Dr Schep said he would not support such a move, arguing cannabis was not without harmful effects.
''I don't think it needs a review.''
He said some users would find other ways to get high, ''but you have to put the brakes on''.
''By banning [legal highs], you're effectively putting the brakes on. You're also sending a signal out that these are not safe.''
