Speeding insulin activation: IM

For those who take intravenous or intramuscular insulin to speed up the time to reach peak activity, do you keep an inventory of longer needles? I was hoping to not to and just use my regular needles or pen tips. Scheiner also talked about rubbing the area and warming the area. Rubbing can be done if out of the house, warming the area, maybe a hot paper towel in the bathroom? Any other ideas?

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Unless you’re devoid of fat and have very thin skin, I think it might be hard to reach the intramuscular region without a substantially larger needle. Do you currently use 6 mm or 4 mm?

@TiaG. I exclusively use 8mm needles, and I don’t think I come close to IM.

I have some 1/2 inch syringes and pen needles (which I use for IM in other areas), but I can easily get IM in the back of my calves with a 5/16 inch (8mm) needle.

It really depends on your body. I don’t have any fat on the back of my calves, so it’s easy to get IM there. But the length of the needle really matters for each person

The rubbing and warming helps speed absorption, but faster than that is to simply use the muscle. Try the back of your calf and then jogging or walking.

For IV, I am able to use 5/16 inch (8mm) 31 gauge needles, which is much smaller than what the labs use to draw blood, so it doesn’t cause much trauma. But I am lucky in that my veins are easy to get to. Again, it will depend on each person’s physical makeup, if they have veins that are easy to access or veins that are further down.

Pen needles and syringes are available without prescription.

I use the 4mm pen needles and 8 mm syringes.

I try the calves/legs too, figuring that they are the larger muscles and I’m more likely to walk than do bicep curls.

Has anyone found youtube videos of IM or IV insulin injection? The IV could understandably be controversial.

I could video an IV injection if you want. Not really hard to do, but you won’t find many people doing this.

IM is much more mainstream. But you don’t really need a video of that. You should just be able to feel the difference. If you go in the back of your calf, you should be able to tell when it gets past the fat layer and into the muscle. Depending on your body type, 8mm might get there for your.

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What is the time to effectiveness differences between:

  1. subcutaneous
  2. IM
  3. IV

realizing that it could vary from individual to individual. ( can be time to peak insulin impact, or time to onset of insulin action. As long as comparing apples to apples)

With your specific data, one can do some guesstimation as to the differences between the speed of onset of insulin for the 3 methods.


It is very hard to give a comparison for subcu versus IM. As you know, there are a lot of factors, including the amount, and temperature, and your muscle usage, and your own personal absorption rate.

So all of this will depend on the individual, but for me, I can figure IM saves me about 15-20 minutes.

IV is almost instant. Just a few minutes to get circulated and it’s already lowering your BG.

Another trick for speed is more insulin.

I don’t want to confuse the issue, but you know how insulin does not deplete in a straight linear fashion? Like the 1st hour you get more than the 2nd hour, 3rd hour, and 4th hour, right?

According to Lilly, the half-life of absorption is about 1 hour. (See: http://uspl.lilly.com/humalog/humalog.html#ppi)

So think about it like this:
Suppose your duration is 4 hours. If you take 3 units, imagine you get 50% in the first hour, and the remaining 50% in hours 2-4.

If you are in a hurry, you want more insulin in the first hour, so taking more results in more being absorbed in the first hour.

Of course, more in the first hour also means more in hours 2-4, so you would need to be aware of that.

A simpler way of saying it is this:
(sticking with a 4 hour duration)
If you need 3 units to correct a high BG, and you inject 3 units, it will take 4 hours for all of that insulin to be absorbed.

But…if you take 6 units, you get 3 units in the first hour (50% like Lilly has documented). That covers what you needed for the high BG, so you have fixed it much faster. Now you just need to contend with the rest of the insulin that will keep trickling in.

Does that make sense?


Yes! Of course, that makes sense, the old non linearity of the insulin depletion trick, as Agent Maxwell Smart would have said on Get Smart. That’s why some people would prefer to correct with a larger dose of insulin and then make up for it later with dextabs or some quick sugar. (I did read about a person who, for some reason, took too much insulin and was literally clutching a one pound bag of sugar, and “holding onto it for dear life” on his way to the ER room because his BG would still drop. He sounded like a recently diagnosed diabetic.)

I guess it depends on everyone’s comfort level and how vigilant we can be in terms of BG monitoring. Some diabetics prefer to correct with the larger dose to bring down a high BG faster and then post correct with fast glucose, while others may take a more conservative approach.


I did read about a person who, for some reason, took too much insulin and was literally clutching a one pound bag of sugar, and “holding onto it for dear life” on his way to the ER room because his BG would still drop.

:rofl:Oh man. I feel bad for laughing but this is such a silly image. Of course, I can imagine the terror of this poor dude – the unrelenting low really is terrifying, especially at the beginning.


I’m sure it works the same way when correcting for a low. Carb absorption is not linear either, so if you’re at, say 30, and you want instant results to raise your Bg you’re probably going to eat more than one chocolate donut (more likely a dozen), and deal with the fallout later.


I had the same reaction to his post because of his description of the event. He seemed to have had a good sense of humor about the episode. For the reasons of not wanting to yo yo and deal with the fallout later, I tend to correct high BG’s cautiously. We all have our nemesis of certain foods, dishes…etc. Mine include dim sum, pizza (more than 1 slice), burger and fries. Majority of the time, I simply eat lesser quantities and that seems to do the trick. Just like insulin absorption is nonlinear, carb absorption is not linear either. Over some carbohydrate threshold, the IC does not work for me. I would then have to dose more than the customary ratio. But then, one has to do with the aftermath. But life is good, I have my supplies of dextabs, or smarties, or my Ghiraddelli 72% Intense Dark Chocolate Squares :slight_smile:

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We were also taking that approach. However due to not being happy with the results and in conjunction with taking advice from Eric, I have been trying to be more aggressive in treating the high and not worry so much about bottoming out. At least when wearing a CGM and watching the graph. When the graph comes down if it does not start leveling when I think it should, it seems to take a very small amount of carb to push it over. Like maybe only 6~8 carbs appear (often times) to stop a rapid plunge from the stratosphere.

Some of the highs can be difficult and really take more to correct then seem reasonable. Without a CGM however, I would simply not be comfortable with dumping what would appear to be an unreasonable amount of insulin.


We pound my son’s highs with tons of insulin, and have found, like you, that just a few carbs can land a high pretty easily. Without a CGM we would absolutely not do this.

This one only took 4 carbs to land.



@Thomas, have you read Sugar Surfing ? This is a reference book for us. Some of his blog posts are even better.


Very good discussion.

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If I want to speed up my insulin activation from a bolus I just do a little exercise and the insulin will kick in pretty quickly afterwards.


That works too.

If it’s a late night dinner dessert, I would go with insulin and skip the exercise. Mid-day extra carbs- for sure exercise is a good solution to speed up insulin activation.

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For a late night dessert i prefer Afrezza because it has a much softer landing for me.


Does IM speed vary with body part? For instance, the standard IM injection that kiddos receive is their semi-annual vaccines at the doctors’ office. These are often administered in the shoulder or upper arm. But I’d imagine a thigh or some other large muscle has more capacity to pull in glucose, right?

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