IM insulin injections: what techniques work best for you?

Our IM injections work really well when they work—but they are hit-or-miss.

When an IM injection works for us, it will give us a much faster action time (25-30 minutes vs 45 to turning the corner), and its effect will be magnified: we will only need about 2/3 dose for the same effect. But we never know if it will come through.

We have used both the thigh and the calf for IM, but lately the calf has been our favorite target. We started with 4mm needles, then went up to 8mm. We are now using 13mm needles. We aim for the round part of the calf, then, once the injection has been administered, we run 5 minutes on it, typically up and down stairs, to get plenty of blood and contractions going.

Despite our changes in technique, we still get only about 40% of our IM shots to work :frowning:

Do you have a good percentage of success in IM insulin injections? What techniques work for you best?

Btw, here is the post, from @Nickyghaleb, that caused me to start this thread:

My thighs. Those are my preferred IM spots, and I agree that it’s hit or miss. I use calves next, but that doesn’t always feel good. I am currently using 8mm syringes, but I’ve purchased 13mm ones. Which sit in my cabinet untouched. They’re a little more intimidating. :grimacing:


Well, I got back from my MRI and realized I’m all out of pods— so MDI it is, and what a great time to focus a little on my IM technique. Thank you, @Michel, for creating the thread. I really do look forward to hearing what people are doing.

And I’m headed home to open my 13mm syringes—now that I have confessed, alone it turns out, to being a wimp. :grin:

Actually, since we’re here— are thighs and calves the most ideal locations? I am not a fan, but I have tried the shoulder (which feels like a flu shot every time) and have wondered about the bum. Are these appropriate alternatives?

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I’m relieved to hear a few others get spotty results, because I’ve largely been unimpressed, using both Humalog and Fiasp. I’ve wondered if I’m not injecting enough, or not going deep enough. And I bruise a lot afterwards. :musical_note:All I want for Christmas is some Af-frez-za, some Af-frez-za, some Af-frez-za …:musical_note:

As for sites, I’ve used calves mostly. My very first attempt was in the shoulder, though I’ve read that has some risks, as there’s a major nerve running close by that is easily damaged. Don’t know if that’s true or a Google Horror Story. I would think on the glutes there was too much adipose to get through first.


I’m just curious… How do you know for sure when you hit the muscle? Is it just the burning sensation that gives it away? Or can you feel that same burning sensation when just hitting a larger blood vessel? Cause sometimes when I inject in the arm, where there is less fat compared to the rest of my body, I do feel a burning sensation and as @Beacher says, there’s often bruising involved. I didn’t see any difference in the absorption, but then again, I never really paid attention to that specific aspect since I wasn’t doing it intentionally.

I would say you don’t know for sure that you hit muscle if it is incidental. If you take a longer than normal needle and jab it into areas where you know there is little subcutaneous fat, and you take an angle straight in, you can be pretty sure you hit the muscle.

My son doesn’t report burning when he does it, and he does it pretty frequently i.e. at least 2-3 times a week.

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So if he does it so frequently I’m guessing he has pretty good results, doesn’t he? How much faster is the action time and how much of the time does he get it right?

He does it when he is stubbornly high, i.e. hormones, or he didn’t react to a previous treatment, and he wants to come down quickly.

When it works it acts in about 1/2 the time to “turn the corner” than a standard sub-Q treatment.

@Chris, how successful is Cody at getting good IMs? As a percentage?

It is pretty successful, but honestly, it is mostly used as a stacking rage bolus, so I suspect most of us would be successful under these circumstances.

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I saw what you said, @Chris, about its taking 1/2 the time as a sub-q treatment as being a sign it has been successful, but I wonder if that’s how everyone would describe success? I’m doing probably 2-8 IM shots a day now, and I do them in place of most of my regular food and correction boluses. I haven’t tracked them closely enough to determine a timeframe, but I see that sometimes it just works, and sometimes my rise gets away from me. Starting tomorrow I think I’ll switch over to 13mm, but I’m just curious how others measure it’s success.

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For me, there are two ways that IMs are different from regular injections: (a) they get more effect per unit and (b) they activate faster.

In our case, we use IMs most often to bring down hormone peaks, where it is really difficult to figure out how much insulin is needed. So it is not possible, for us, to judge the success of an IM by how much it dropped your BG (since we don’t know precisely how much of a drop we will get).

How we measure if an IM injection is successful is by timing it: if it turns the corner much faster than a regular one, it is successful. On that basis, about 40% (plus or minus) of our IM injections are successful.

If it turns the corner in the same amount of time (or more) as a regular injection, then we did not succeed in doing an IM.

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I have pretty much the same experience with IM injections. When they work, they are amazing. But they are SO hit-or-miss. I wish I could find a way to hit the muscle every time. I use 12 mm needles and tend to use my shoulder, right where they do the flu shot. But that’s still no guarantee, and I’d say I miss more often than hit.

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Wonders never cease. Dare I ask why? I’ve only ever thought of them as an extreme measure when SQ corrections don’t work, not as a replacement for regular boluses or as pre-emptive.


Of course you can ask why. :smiley:

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Would it be annoying if I offered the possibility that maybe some of these BGs just require more insulin?? Are you talking about times when you’re absolutely positive you know what his blood sugar is going to do?

I’m not trying to be difficult. It’s one of the things I dislike about diabetes— from my dwindling list. :smiley: It’s the uncertainty over whether or not I’ve done enough… enough insulin or carbs. There have been plenty of times when I thought I had done enough of a correction only to find I out I needed double that an hour later. Because of these incidents, I find myself checking my infusion set, wondering about scar tissue, etc. As you were saying that, in that I also believe the same to be true, it made me wonder how often my rise was just more acute or pervasive than I had anticipated and not that the IM wasn’t a success.

I hope you don’t read this as I’m wondering whether or not you are making mistakes because I’m not. I’m thinking out loud. The other day I had that BG that rose to a 400. I was wearing an OmniPod AND doing IM injections. I blamed it on having had a leaky site and injecting air into my muscle. :smiley: Looking back, however, maybe neither was the case, and that particular rise just needed more insulin than I thought.

Okay. More on point is the fact I started using the 13mm syringes last night— marked in mL instead of units— and… it’s been hit or miss. :smiley:


That is why I don’t use returning to range as the criterion of success:

Instead, we would like to see a downward corner int he BG data, that shows where IM insulin hit. If it happened in 25-30 minutes for us, or, in general, significantly earlier than for regular injections, then I think we can say the IM injection worked.

This downward corner, though, may be just an inflection, or a couple of points down in the middle of a general upward trend, if you need a lot more insulin. So it may not bring you down, but it still can be a successful IM injection if it worked fast (just not enough insulin).

Where I agree with you, though, if that, for us, when your upward trend is truly powerful, an injection of any kind that is really too small may not show on the upward trend. That is, of course, frustrating, but happens to us often. In this case, if we used an IM, we count it, according to my criterion, as a failed IM, even though, as you point out, it may simply have been way too small an amount of insulin.

But, so far, we cannot think of another way to measure IM success: somehow, we have to relate it to something we can measure. So, this leaves is underestimating slightly the percentage of successful IM injections.

To be 100% clear: to us, a successful IM injection is not one that treats the high (since that depends on the amount of insulin as well), but one that shows IM characteristics: speed in insulin reaction time and high insulin efficiency.

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I’m not sure why, but I’ve never considered anything else as a way to measure it.

I like this very much. I’m just now getting in the habit of setting my timer to remind myself to check my BG again after doing a correction. I really don’t need to do it all of the time, but when I suspect a sticky high, it’s in my interest to check in to see how it’s going. I’ll have to start making note of whether or not I think there’s evidence of the IM shot’s action.

Thank you! This makes perfect sense. :slight_smile:

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Sorry, @Beacher, I was planning on coming right back to tell you why I’m doing so many IM shots— and not leave you with only the permission to ask— but life got in the way. Either way, here I am.

I don’t have a better answer than that it is working really well, and I like its results better than I do the boluses delivered via pump or subcutaneous injection. It feels more… tangible. Heartier—if you will. The other day I couldn’t find any 5mm pen needles, and I was forced to use those little tiny ones. It was the first time I realized how important the type of injection is to the action of the insulin. And I know that you all in here have been thinking that way since the time you learned to walk, but it’s a new world to me— this world of insulin. So I’m basically using the IM shots for food boluses and correction boluses when I feel like I need to see action quicker. I haven’t really found a way to track it yet, but in general, I feel like I’m seeing the kind of results I’m hoping for, which makes me believe much of it is working. If my blood sugar is on the low end, I’m treating, and I know I need insulin on board but not quickly, I do a standard shot— or use a pump (if I have one on).

I feel like it gives me more control. I’m still working on the better part. :smiley:

So. Hit me. What is wrong with all of that I’ve just said? Actually— that’s a leading question, and I don’t mean it to be that. If you understand any of what I’ve said differently than how I’ve stated it, I welcome your explanation. Truly. I’m really enjoying everything I’m learning here and about my diabetes, and I’ve still got plenty of misconceptions that need a little straightening. :slight_smile:

Nothing! Hey, if it works for you, great! There’s no one way, as we see on a daily basis here. There are unlimited ways.

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@Beacher, that was a ridiculous question, and I tried to fix it right away. My real, genuine question was what are the downfalls, as you see them, to using IM shots as a regular part of daily management of blood sugar and not just as extreme measures when SQ corrections don’t work?

That first question was a trap. :grin: The second question, however, is a genuine attempt to understand.

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