• Steve Mann

Know Thy Insulins

Why is it important to understand how different insulins work?

As kind as possible, your doctor may not be up to date with the latest developments in the field. It happens. And you need to know as much as they do to (1) have a constructive conversation with your doctor and (2) make an informed decision about which one is right for you. For instance, Novolog works slightly faster than Humalog, even though they are almost identical chemically. The difference is one amino acid in their DNA structure, but it’s enough to alter the pharmacokinetics (how the drug moves through the body and what the body does to the drug). These small changes will impact how your diabetes is managed.

Insulin has three main characteristics

Onset: is the length of time before insulin reaches the bloodstream and begins lowering blood sugar. Peak time: is the time during which insulin is at maximum strength for lowering BGs. Duration: how long insulin continues to lower blood glucose.

Multiple Insulin Types

I remember three types of insulin at the time of my exile by the Sugar Gods

NPH Insulin: Neutral pH (pH = 7), Protamine (a protein), and Hans Christian Hagedorn (insulin researcher). In 1936, Hagedorn discovered that the effects of insulin could be extended by adding protamine from river trout semen. It is an intermediate acting insulin with an onset of 90 minutes and action up to 24 hours. It's been around for a long time... since 1946.

My questions are:

1. Whoever thought of using trout semen? 2. How do you collect trout semen?

Regular insulin: – short acting relative to NPH, and is typically mixed with longer acting insulins like NPH… that’s what I had to do.

Lente insulin (comes from Italian lente, meaning "slow") was an extended duration insulin no longer used in humans. The onset of lente insulin was one to two hours, and the peak effect was about 8 to 12 hours after administration, with a duration of more than 24 hours. Lente, which comes from pigs and cows, as most of these early insulins, had zinc added to it to extend its effect.

Insulin Dosage Strengths

Insulins have different strengths because some people have larger or smaller insulin requirements. If that is the case, the only way to get your dose without multiple injections or using a syringe that doesn't have small enough increments is to use a non-U-100 strength.

U-100 is the typical strength, and means there are 100 units of insulin in one milliliter of fluid.

U-500 is five times more concentrated than U-100 regular insulin, and is used if your insulin requirements are substantial.

Other concentrations include U-40, U-300, and if I recall U-80 as well.

Up until the 1970s U-40 was the most common form of insulin strength, but has been largely phased out.

Insulin Onset and Duration Types

Ultra/Rapid-acting insulins work over a narrow, more predictable time range. Because they work quickly, they are usually used at the beginning of a meal. Some require a pre-bolus, others like Fiasp and Lyumjev do not need much pre-bolus at all. I know a few folks who actually take their bolus after their meal.

Rapid-acting insulin is closest to how endogenous (internal human insulin) operates, but still has a way to go in terms of onset and effectiveness.

Another category of insulin - called short-acting - is also included, but I find it has similar characteristics to rapid and intermediate-acting insulins.

Intermediate-acting insulins take effect and wear off faster than long-acting insulins, but have a longer duration than ultra-acting insulins.

Long-acting: Some insulins contain added substances (buffers), which causes them work over a longer period, and can also make them appear cloudy. When these types of insulin sit for a few minutes, the buffer settles to the bottom of the vial. But insulin glargine and insulin detemir are clear liquids (not cloudy). These insulins have no peak effect and can last anywhere from 16-42 hours.

Major Insulins on the Market

Being a diabetic is a constant exercise in education.

It's part and parcel of the life-style.

Here’s to being an avid learner.


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