What Is Insulin?

In the topic of diabetes, you’ll hear a lot of terms thrown around: blood sugar, pumps, diets. These are all important concepts and we’ll visit them later, but when it comes down to it, one thing reigns supreme – insulin.

But what is it?

Before we can get to that, we need to first identify a few other key players.

The cells in our body need fuel to survive and thrive. We get this in the form of glucose, the most essential gas to our cells’ engine. Carbohydrates (and even protein) can be broken down from complex carbs into simple sugars for our body to use, the most abundant of which is glucose.

Insulin is a hormone produced in our pancreas that aids in our body’s ability to use glucose. Think of it as a key that unlocks our cells to allow glucose to enter them. Once inside, the cells slurp up the glucose and give us energy.

Sometimes our body produces antibodies that mistakenly attack the insulin-producing beta cells in our pancreas. This is type-1 diabetes (T1D). Without those beta cells, our body can no longer produce insulin which means we can’t unlock our cells to take in the glucose.

If you’re diagnosed with T1D, you need to put insulin in your body from an external source. This is usually done via a pen, a syringe, or a pump (there is also an inhalable rapid-acting insulin available as well.)

The insulin is injected under the skin into the subcutaneous fat that surrounds your body. There are different types of insulin that will are absorbed at different rates. The table below is a (very) general look at two of the main types:

Onset TimeDurationMain Use
Rapid-Acting15 minutes2-3 hoursTaken with meals to compensate for carb intake and correct high blood sugar.
Long-Acting2 hours24-36 hoursTaken once daily to act as a background regulator.
There are others that act quicker or longer. Talk with your doctor about best treatment options.

The History Of Insulin

In 1889, German physician Oskar Minkowsi was working on theories that evolved from the discovery of the Islet of Langerhans (by Paul Langerhans) a couple decades earlier. Minkowsi removed the pancreases out of healthy dogs and discovered their urine was increasingly full of sugar. This began the link between the pancreas and diabetes.

Several scientists would work on isolating the actual key molecule responsible for glucose metabolism with some even finding an aqueous pancreatic liquid that, when injected into a diabetic dog, seemed to regulate blood sugar. Most of these works were interrupted by the onset of World War I.

On July 30, 1921, Sir Frederick Banting and Charles Best, were able to isolate the hormone from the pancreas of a dog. Previous experiments saw the hormone destroyed upon extraction, but Banting was able to use a ligature process to dispose of the insulin-destroying digestive enzymes and successfully extracted insulin. He injected this into a diabetic dog and saw rapid lowering of blood sugar levels.

Fun Fact:


Over the next few months, Banting was able to extract insulin from the pancreases of dogs, calves, adult humans, and what humans would proceed to use for the next several decades – pigs and cows.

Only several months later, in January of 1922, the first patient was injected with insulin. 13 year-old Leonard Thompson saw a reversal of his glycosuria (sugar present in urine) and started regular insulin treatments and went on to live another 13 years at a time when a diabetes diagnosis was usually fatal within months or weeks.

Insulin Today

Today, most insulin is artificially created by introducing the human insulin gene into bacteria and fermenting it after which it can be harvested and turned into life-saving medicine.

Three companies dominate the global insulin market – Eli Lilly, Novo Nordisk, and Sanofi – who produce almost 100% of the supply in the United States.

For a bit of context: Banting, Best, and Dr. James Collip sold the patent in 1923 to the University of Toronto for $1 with the direction that it was only so others could not make a patent and profit on its monopolization.

“Insulin does not belong to me. It belongs to the world.”

-Sir Frederick Banting

The price of insulin has risen from 0.2 cents per insulin unit in the 1960s to as high as 48 cents per unit in 2021.

A prefilled pen will usually have 100 or 300 units in it, depending on if it is a long-acting basal insulin or quick-acting bolus insulin. For the latter, a general rule of thumb is to take one unit per 10 grams of carbohydrates. The actual amount you take will be decided between you and your medical team.

With a quick bit of math, you can see that the price of insulin has increased incredibly over the past few decades. A single serving of rice (at 40g of carbs) could cost about $2 worth of insulin to eat.

Due to price, availability, and logistics (among other factors), many people who need insulin to survive or correctly treat themselves don’t have access to it.

  • A 2021 WHO report found that roughly one in two people with Type-2 diabetes who needed insulin to properly treat themselves had access to it.
  • A 2021 NIH report found similar results with people in low to middle-income countries having even less access.

Insulin In The Future

There are positives, however. Medical science continues to improve and there are potential advancements on the horizon.

Technology is getting better. For example, insulin pumps were controlled by the wearer, but have now evolved into artificial pancreases which automatically release insulin based on the blood sugar readings of a CGM. This frees up a diabetic from having to constantly be reading, calculating, and administering insulin.

In a recent study at Washington State University, scientists discovered how bears regulate their insulin to match their calorie consumption, which could lead to breakthrough advancements in treatment in the future.

The current US administration signed a bill that will cap monthly insulin prices at $35/month for seniors, which will greatly impact those who need multiple vials each month. While this only applies to those who receive Medicare, it could trickle into further legislation in the years to come.

Diabetes is a life-threatening disease and insulin makes it possible for those diagnosed to survive. Continue to learn and support as we celebrate National Diabetes Awareness Month.

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