Diabetes NZ wants Pharmac to fund a "life-changing" device that can measure diabetics' blood sugar levels instantly.

New Zealanders living with diabetes can now measure their blood sugar levels instantly through a new continuous glucose monitoring (CGM) system, which launched on Tuesday.

The FreeStyle Libre 2 is a small wearable sensor that attaches to the back of the wearer's arm and shares glucose data to a smartphone app.

Previously, people living with diabetes were required to prick their fingers and draw blood many times a day to monitor their glucose levels.

Diabetes New Zealand chief executive Heather Verry said the technology has been around for a while, but the new sensor has the added benefit of having alarms.

The sensor gives information to the smartphone or meter, she said.

"It now sets off alarms to highlight to people that their blood glucose levels are trending high or low, so that's a really huge addition to this technology."

The technology was life-changing for those with diabetes, she said.

"Quite apart from the fact that they don't have to prick their fingers every few hours, which is something. It also gives people the opportunity to better manage their diabetes, less days off work, less hospitalisation."

It could also help prevent the onset of diabetes complications such as renal failure, blindness or lower limb amputations.

The new alarm would help the whole family, Verry said. Until now parents have had to wake their diabetic children at night to ensure their blood levels were regular which meant neither the parents nor the child had a good night's sleep, she said.

"When you're living with that seven days a week and there's no break from it - you can't go on holiday from diabetes, it's there with you."

The system was publicly funded in Australia and the UK, but unfortunately the new system was not funded by Pharmac, she said.

"It's a real issue for us because it's an equity one and only those that can afford it will be able to take advantage of such wonderful technology - and at $50 a week it's a huge cost."

They had been petitioning for better access to continuous glucose monitors, she said.

"We know that it's sort of gone through loops that it needs to go through in Pharmac and it's just sitting there waiting for the budget."

Considering the costs of hospitalisations and diabetes complications, funding the device was "really a no-brainer", Verry said.

Pharmac was approached for comment, but didn't immediately respond, reports RNZ.

-RNZ.