Is a unit of insulin a unit of insulin?

Quick question for everyone that I can't seem to find the answer to, maybe my info hunting skills need an upgrade...but... Is a unit of insulin a unit of insulin? Meaning....

All things being equal, body chemistry aside, duration, time action begins, etc... Does a unit of lets say levimir, equal a unit of novolog in terms of ISF and or I/C ?

To further explain, if you take 20 units of levimir and it's "supposed" to last 24 hours, so 20 units divided by 24 hours gives you 0.83.

That 0.83 units of levimir an hour, is that the same as if you were to give yourself 0.83 units of novolog an hour (time of onset, duration, etc withstanding)... Will both have the same effect on BG correction and or offsetting carbs?

I hope I am making myself clear, this is the only way I can think to explain my question. Thank you in advance, I am so grateful to have these forums to help with questions and to learn from.


A unit is a unit. What is different is the time it continues to work in your body. Novolog generally lasts 4 hour. So if you take 1 unit. 1/4 unit iw used in th first hour, etc.

If you take 1 unit and the insulin is long acting, say 12 hours, then 1/12 of a unit is used every hour. (Its about time...its about space...its about the whole human race..and it all started with a BIG BANG!!) It is all about the science.

Time is the big key, along with dose.

Yes. Yes. Yes. Yes. What is different is the timing.

Well, yes and no. I found that it took a lot more Levemir than Lantus to keep my blood sugar reasonable. A lot more. I first started on Lantus, and gained a twenty five pounds. My endo switched to Levemir because it is supposed to be more weight neutral. i had to increase the amount like mad.I did stop gaining weight, though. By the time I switched to the pump, I was taking 50 units of Levemir a day, and with the pump, my basal was between 24 and 25 units a day of Novolog. And the 50 units of Levemir weren't getting the job done, at that. it's just too big a difference to be accounted for by pump efficiency.

Unfortunately, in my opinion, things are not quite that simple. Comparing as you say, Levemir and Novolog are kind of like comparing apples and oranges, even though they are both insulin. Levemir is a long acting (basal) insulin used for background coverage, and Novolog is a fast-acting or bolus insulin used for mealtime. You wouldn't apply ISF or I:C to Levemir, because you don't use it to bring down your blood sugar when it's high or to cover your carbs.

As for 20 units of levemir lasting 24 hours, it often doesn't, it's often more like 22 for most people. And it doesn't really give you quite as smooth a coverage as to be evenly divided by hours. That's why people like pumps! You can determine exact hourly basal rates.

Your question about giving yourself 0.83 units an hour of one or the other is also not exactly accurate, because you can't give yourself .83 units of levemir for just one hour, it is long-acting insulin. When you do set basal in a pump you use fast acting insulin in small hourly rates. Some people whose pumps malfunction try and substitute equivalent hourly shots of their fast acting but I don't know how well that works. it's not something you'd do under normal circumstances. And finally, Levemir doesn't work well to correct bloodsugar or offset carbs because it doesn't work quickly enough.

I may be missing what you are trying to understand, because you say "duration, time action, etc aside" but you can't put these things aside when you compare a unit of levemir to a unit of novolog; they are central to how those two forms of insulin function in your body.

Perhaps you can help us answer you better by telling us if you are just asking out of a desire to gain general knowledge, or if there is some specific purpose you have in asking the question.

Well now you have truly lived up to your handle, From my understanding though, neither insulin gets used in a linear manner, if Novolog lasts 4 hours it isn't used exactly evenly. I believe it goes by an algorhythmic formula, but I could be wrong about that name.

I am just trying to get a deeper understanding of how the chemicals work without time as a factor. So to ask this question another way, if you took a snapshot of 5 minutes in time out of 2 different days. On the first day during the 5 minutes you just happen to have 5 units of levimir acting at full strength on your body. On the second day you happen to have 5 units of novolog acting at full strength on your body. For those 5 minutes is the effect the same on your body on each of the days?

Thanks, Zoe. I try. Live long and prosper!

I agree with the evenly comment, but my brain cannot totally deal with that complex algorithim... So divided by 4 works good for me.

I would not totally stress about the chemicals and 5 minutes--way too much math! Watch your glucose levels (chart or CGM) and analalyze. You will slowly learn, as it all depends on your body's raction. Five minutes?!?! Too much stress.

The idea is that you're getting 'x' amount per hour because the long acting insulins release slowly over time...

A similar amount per hour is probably absorbed, but not necessarily the same amount.. Maybe when we have nanobots we can inject to regulate how much insulin we're getting per hour, it will work that way..

Its only a hypothetical. I suppose I am not asking my question in a way that makes sense.


5 units of Levemir is going to release slowly over X amount of hours.

5 units of Novolog is going to be absorbed more rapidly, leading to a more profound and shorter acting effect..

I am not making my question clear. It is a “what if” but thats okay I appreciate everyone trying to help. Thank you!

You can't remove time from the equation; the answer wouldn't mean anything. When did you take the 5 units of Levemir? When did you take the 5 units of Novolog? I suppose if you could somehow magically figure out the equation to adjust the time of dosage so that exactly 5 units of each was acting in your body at the given 5 minutes...yes, it would have the same effect. But....have you ever heard the saying: "If my mother had wheels she'd be a cart?". that kind of tells you how little meaning the answer would have! I agree, with Spock, much more important things to focus on!

Insulin is measured in units, abbreviated U
(international units, previously abbreviated IU).
One unit of insulin is defined as the amount of
insulin that will lower the blood glucose of a
healthy 2 kg (4.4 lb) rabbit that has fasted for
24 hours to 2.5 mmol/l (45 mg/dl) within 5

If you read Bliss's "The Discovery of Insulin", when Eli Lilly was standing up their first plants for the processing of insulin, they rounded up nearly every rabbit in Indiana and adjoining states for the purpose of testing their formulations :-)

I never had Lantus/ Levimir but noticed that pumping Novolog was a ***tremendous*** improvement over shooting NPH, like within a couple of hours of pumping I could tell.

Found a helpful chart that can explain some of the insulins and how the work, but it's going to be different for each person as well. That's the crazy thing about this disease. As much as we want it to be an exact science, it isn't. If we could plug in a formula to figure everything out, we could have perfect control all the time. Well, here is the link and good luck.

So rabbits are a lot more consistent than humans?? You definitely couldn't use humans in a similar equation!

The answer to your question is, "No!" 1.0U of Levermir is not the same as 1.0U of Novolog. This is because of the timing of the active period for each.

The measurement in volume is the same.

That's what I did when I was on MDI as well.