Proposed tougher penalties for using and dealing N-bomb won't take effect for almost a year.

Fourteen people were hospitalised last month after using the dangerous designer drug.

The government is proposing a three-month maximum prison term for possessing N-bomb and a 14-year maximum sentence for selling the drug.

But Associate Health Minister Peter Dunne said the proposal has a long way to go.

"The process is a reasonably lengthy parliamentary one, so it's probably likely to be the middle of next year before this takes absolute effect," he said.