A survey by Massey University suggests the drug methamphetamine, or P, is losing its appeal among drug users.
But the study also reveals that cocaine and ecstasy are becoming more popular.
More than 400 drug users were interviewed in Auckland, Wellington and Christchurch in the Illicit Drugs Monitoring System survey.
Lead researcher Chris Wilkins says its findings show P is less favoured by users because of the risks involved.
Dr Wilkins says the results suggest ecstasy and cocaine are becoming more popular but there is a decline in the use of cannabis by people under the age of 45 because of the risk of smoking.