Police say a yet-to-be released Ministry of Health survey suggests the number of people using methamphetamine has more than halved.
However, a methampetamine education group, Methcon, is warning that it is too soon to start celebrating.
Detective Senior Sergeant Chris Cahill told a seminar at Auckland University this week the survey suggests the percentage of the population using methamphetamine, also known as 'P', has dropped from 2.1% to 1% since 2008.
Mr Cahill says police on the street have noticed a reduction in meth use, and fewer new users.
He says society now sees methamphetamine as socially unacceptable and police need to focus more on getting medical treatment for people who are addicted to the drug.
Police say seizures of pseudoephedrine, an ingredient used to make 'P', coming from China have dropped significantly in the past three years. Mr Cahill says it could be that 'P' manufacturers are using different chemicals to make the drug, as the supply has not dropped off.
However, police say a lot more cocaine is arriving, which is cheaper to buy.
Methcon says people should not put too much faith in the Health Ministry survey because statistics on drug use are inherently unreliable.