The discovery of insulin

The discovery of insulin has been one of the greatest medical advancements in modern times and has saved millions of lives. Before insulin, a diabetes diagnosis was a death sentence. If people followed a strict diet, they might live a few extra years, but it was insulin that gave people a chance at life.

Our bodies need insulin, a hormone produced in your pancreas, to break down the glucose so it can enter your cells. If you have diabetes, it means your pancreas makes too little insulin, or none at all.

The breakthrough came in 1921 when scientists Frederick Banting and Charles Best figured out how to remove insulin from the pancreas of a dog. They used it to keep another dog with diabetes alive for 70 days. Armed with this knowledge, the researchers, along with colleagues James Collip and John Macleod, developed a more refined form of insulin from the pancreas of cows.

Isolation of insulin & distribution

This advancement led researchers to a Toronto Hospital, where a 14-year-old boy, Leonard Thompson, was dying of diabetic ketoacidosis. Within 24 hours of being given insulin, Leonard’s dangerously high blood glucose levels dropped to near-normal levels. However, the first injection was a partial failure because the insulin was not pure enough. After 12 days of testing his insulin, Collip repeated the injections with Thompson and this time, it was a success. In the weeks that followed, he received daily injections and gained weight and strength.

Researchers knew it was an incredible development that would change the future for millions of other people living with diabetes. Soon after, an agreement was reached with pharmaceutical company Eli Lilly & Company to distribute insulin on a larger scale.

Insulin in Australia

In 1923, six-year-old Phyllis Adams became the first Australian to be treated with insulin. The insulin was sent to Sydney on board a P&O ship from Vancouver, wrapped in cotton wool. Her father, Harry Adams, a machinery merchant, met the ship mid-harbour to collect the insulin which he rushed home to the waiting family doctor. Phyllis weighed less than 10 kilograms when she received the first injection. Phyllis Lush (nee Adams) went on to live a long life, passing away at the age of 81. According to the Guinness Book of Records, she was the longest living person to receive insulin.

Key dates

1921 – Surgeon Frederick Banting and research assistant Charles Best discover insulin at the University of Toronto.

1922 – 14-year-old Leonard Thompson becomes the first person to be injected with insulin as he lay dying at the Toronto General Hospital.

1922 – Insulin first mass-produced by Eli Lilly.

1923 – Six-year-old Phyllis Adams is the first Australian to be treated with insulin. Dr Frederick Banting and Professor John McLeod receive the Nobel Prize in Medicine for discovering and isolating insulin. They split their prize money with research assistant Charles Best and Bio-chemist James Collip.

1936 – The first commercially available extended-action insulin, PZI is released. Sir Harold Percival Himsworth proposes separating diabetes into type 1 and type 2 diabetes.

1946 – NPH, a fast-acting, insulin is released.

1953 – Lente insulin, the first intermediate duration insulin, is released.

1963 – Insulin becomes the first human protein to be chemically synthesised. First prototype of a ‘pump’ that delivered glucagon as well as insulin was developed by Dr Arnold Kadish.

1973 – Dean Kamen invents the first wearable infusion pump.

1978 – First synthetic ‘human’ insulin is created. The world’s first portable blood glucose monitor is developed in Australia by Stanley Clark and is rapidly adopted. Home glucose self-monitoring becomes a reality.

1979 – The first glucose oxidase strips are listed on the National Health Scheme.

1980 – Single strength insulin is introduced in Australia.

1986 – The first insulin pen is released.

1999 – More than 470 people with type 1 diabetes receive islet cell transplantation. They don’t need to administer insulin as long as they use immunosuppressant drugs.

2013 – The University of Cambridge develops an artificial pancreas that pairs the technology of an insulin pump with a continuous glucose monitor.

2015 – Dr Edward Damiano introduces the iLet, which he calls “a bridge to a cure.” The device is a bionic pancreas that delivers both insulin and glucagon every five minutes as required.

Insulin today

For many years insulin from cattle and pigs was used to treat diabetes, and while it saved millions of lives it also caused allergic reactions in many patients. In 1978, the first genetically engineered, synthetic ‘human’ insulin was produced using E. coli bacteria to produce the insulin. The first commercially available biosynthetic human insulin went on sale in 1982.

There are now many different varieties of insulin, from regular human insulin identical to what is produced by the body, to ultra-rapid and ultra-long-acting insulins. People with diabetes can choose which formula best suits them.

While there are treatments available for people with diabetes, there is still no cure. It is something scientists continue to work on.

In 2021 we mark 100 years of insulin. Federal Parliament’s diabetes support group has acknowledged the impact of insulin and called for the House to recognise the seriousness and complexity of diabetes.

People with diabetes require ongoing care and support in order to live well with diabetes and avoid complications. On World Diabetes Day the campaign aims to raise awareness around the importance of improving access to diabetes care and highlighting the need for more action to prevent diabetes and its complications.