A hundred years ago Canadian researchers discovered insulin, saving the lives of millions world-wide including 450,000 Australians who now rely on it daily.

A hundred years ago in a borrowed lab, two Canadian researchers had a breakthrough.

Months later, a malnourished six-year-old girl weighing less than 10 kilograms stood on Sydney's Pyrmont wharf awaiting the first of some 65,000 injections that would change her life.

When Phyllis Lush was diagnosed with diabetes the year before, the condition was a death sentence.

Caused by little or no insulin production, diabetes resulted in soaring high blood sugar levels, which could only be controlled through an unsustainable, extremely restrictive diet.

Sufferers would drastically shed weight until they slipped into a coma and died.

But her parents refused to accept that fate for Phyllis.

Her father had heard of the Canadian experiments and desperately wrote to Frederick Banting and Charles Best asking of their progress. Could they save Phyllis?

"We're close, keep her alive," came the reply.

And so for eight months, Phyllis was kept going on only a lettuce leaf, a teaspoon of butter and whey each day.

"It was nothing. She was skin and bone," her son Studley Lush told AAP.

"Before mother got insulin, her sister who was about two was bigger than she was."

When the ship carrying the first dose sent to Australia arrived outside Sydney heads in 1922, Phyllis' father and doctor rushed out to meet it and then back to the wharf where they injected her on the spot.

Almost immediately, she began feeling better and was fed her first proper meal.

"They gave her half a SAO biscuit and she remembered it as the best meal she's ever had," Mr Lush said.

"And then they were told she should probably live until she was nine. She lived until she was nearly 82."

Phyllis was the first Australian and among the first in the world to receive the life-saving hormone. A century on, over 450,000 Australians rely on it daily.

"This insulin discovery was one of the great discoveries of the 20th century - there's no doubt about that," Diabetes Australia chief executive Professor Greg Johnson told AAP.

"You can compare it with the discoveries of antibiotics. It has transformed the world for huge numbers of people."

Beginning their experiments in May 1921, Banting and Best figured out removing a dog's pancreas triggered diabetes.

By November that year, they had successfully managed the disease in a dog by injecting it with an extract made from its own ground up pancreas.

In January 1922 they administered their first dose to a human and a year later were awarded the Nobel Prize in Physiology or Medicine.

Massive strides in managing the disease have been made since.

When Phyllis was young, she'd be picked up from birthday parties when the food came out, unable to bear watching her friends eat cake, and taken back when the meal was over.

"Every bit of food she had was weighed and the calories were counted," said Mr Lush, who also developed type one diabetes in his 50s.

"These days it's much easier to control. We have all sorts of medication ... and you can eat almost anything in moderation."

Originally created from cows and other animals, most people with diabetes now use synthetic "human" insulin, which comes in fast-acting and long-acting forms to cater to different needs.

Even the tools to administer it have changed drastically, Prof Johnson says, from 'frightful' and 'cumbersome' needles to the tiny single-use pins now available.

"These new devices can pretty much do what a pancreas would do in a person whose own doesn't create insulin," he said.

However managing the disease is still an extreme financial burden.

The average lifetime cost of type one diabetes - which is not preventable - is $400,000 per person, according to the Juvenile Diabetes Research Foundation.

So while Phyllis would marvel even at the huge progress made since she died in 1998, Mr Lush says she would be disappointed we haven't achieved one thing.

"Her greatest wish in life was that they would find a cure."