IV or IM injections for extreme highs?

If my BS is above 300 I will change my infusion set and give a sliding scale bolus with the new set, but I also give a bolus via injection. The bolus I give though is IV for the most rapid treatment. I have prominent veins so it’s relatively easy. Wondering if anyone else does IM and how they feel absorption compares to Sub Q or IV.


I’ve done IM a few times when a high refuses to come down. I find the results vary widely. I may drop fast, I may drop the same as I would with a subQ, or it may not have any effect at all. Given this unpredictability – and when I’m dealing with a sticky high, I want some predictable result – I lean towards taking large doses by old-fashioned subQ.


My son gives IM shots into his calf when dealing with stubborn highs. They seem to work faster than SubQ. He has not done anything IV. When @Eric gets back from vacation he will probably have a bunch more to say about IV.


What do you all feel the difference is in timing of insulin kicking in IM vs SubQ? I hadn’t known people do other than SubQ injections of insulin

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I have had a similar experience with IM injections. i find, though, that if i have been active, the absorbtion is very quick (within 1/2 hour). so, when i inject, i will exercise my muscle (my mid-thigh is where i like to inject; maybe i should try somewhere new). if not exercising the muscle, i will massage it to get the blood circulating. this seems to help. but there are other times when nothing happens. i dont think that this is due to anything other than a really stubborn high BG. i will wait 1 hour after the IM and if there is no downward movement, i will give myself another shot. i find that the IM shot insulin is in and out within 2 hours (as opposed to the 4 hours of subQ injections) (which is definately part of the IM convienience.)


Hi @Dc53705, I do all of them. I learned from a friend here, but he’s MIA right now. So I can tell you what he’s taught me about them, all of which I have found to be true… and then maybe see if we can’t bait him with this thread. :thinking:

I am on the t:slim, so my options include a regular pump bolus, a manual sub-q injection, IM, and IV. And I mix them all together all day long… as long as I’m home. In the interest of avoiding a scary infection, I won’t do IV shots outside the house.

In regard to timing, sub-q is slowest, both pump and manual injection, often taking as long as 45 minutes to really start to do anything. I like it when I just want to keep the insulin on board but know I have no real immediate need. I also use it when I’m treating a low and expecting a rebound. If I do a small sub-q bolus, either through pump or manual injection, it’s slow enough to help slow the rise without causing too quick a turnaround. For me, the sub-q requires the most patience and the best organization. Because those aren’t my strengths, they can lead to frustration… and ultimately can lead to general screw it thinking.

IM just feels more effective. It feels like I’m doing something when I bolus this way. I’ve never timed it, but I’m thinking, based on what I can recall of my friend’s information and what appears to hold true, that I can expect to see some movement after about 20 minutes or so. I also go off the assumption it’s out of my system in about 2 hours rather than the 4ish it takes a sub-q to be complete. For this reason, I’ve switched to doing IM shots for my coffee in the morning. I like to try to run midday, so the earlier I clear what I have on board, the better. The biggest problem I have with the IM is not having anyway to confirm I’ve actually done an IM. I have read about proper technique and tend to use my thigh muscle, but I really can’t be sure I’m hitting muscle as often as I like to think. I finally bought longer needles… and just wimp out every time I go to get one. :roll_eyes:

IVs are, hands down, my favorite. I’ve learned to mix them in, sometimes giving myself both a pump bolus and IV to cover more time. This one I have actually timed. 10 minutes and I start to see a turn. Then there can be a wicked fast drop. This shot I use only under certain circumstances. If I’m already borderline high but am about to have coffee or something else that is definitely going to spike me— or if I need to bring down a ridiculous number and would like not to have to wait 3 hours… But this one is never used preemptively. It’s just too fast. I work under the assumption here that the IV is working as quickly as 10 minutes later (confirmed) and is out in an hour. I’ve tried to confirm this, but it can get tricky. I can say though that I’ve seen good stable numbers an hour after an IV enough times to say I think it’s about right.

I’d love to hear your thoughts on it all. There’s not often mention of this, and I am definitely hooked. Thanks for posting!


Sounds like Afrezza is even faster at kicking in and clearing out. I’m not sure if you’ve used it. If you have – or if anyone else has – can you compare the experiences?

I think when Afrezza finally comes to Canada :sleeping:, it would be my choice over IM or IV for dealing with stubborn or extreme highs.


I’ve got a guy in my group who loves it. The way he described it, it did sound faster than IM… but I still don’t think faster than IV. There is another gentleman in my group, who I believe is a doctor, if my memory serves correctly, who mentioned Afrezza and IV in one of his posts. He was talking about the unknown long term side effects and whether they were any safer than the risk of doing IV. At that time, he said he thought the risks were about even. So I asked the commenter from the other day whether he knew anything about long term side effects (specifically lung issues), and he said he has been swimming for 35 years and has seen no difference yet. So no immediate effect. Then he posted this link to see what they’re saying on it so far.

Not sure if MannKind just presented or ran the tests themselves. I tried finding more information on it and fell asleep.

I agree it would be great to be able to use something that was designed to act that quickly and drop everything else, but I feel like, at this point, I can take care to minimize risk with what I’m doing currently. Maybe Afrezza will be fine, but I know I’d be more comfortable after they’ve had some more time looking at it.

I don’t even know what you asked. All of this has been on my mind, and you hit all the keywords. Oh! The guy… I will go find his post and see what he said about the timing…


When I use 4 or 8 unit Afrezza, I see a change in dexcom trend in the next 2-3 dots.

I have tried split 2s, and get less predictable trend move, so usually do 4 unit, with small snack if goes low.

The units do not align with liquid insulin for me. 4 Afrezza is closer to 2 humalog.

I have never done IM or IV.


I use it—starts working in 10-20 minutes depending on how high I’ve gone and is done working in about 1 1/2 hours.


@Nickyghaleb these timings are with novolog?

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With novolog, @LarissaW, yes. I’m definitely asking my endo about an Afrezza sample though.

And the IV shots really are something I’m very careful with… I don’t want anyone to get an impression otherwise. There are far fewer instances throughout the day that allow for one than ones that don’t. So for 10 considerations, I might find one scenario where it’s a good fit.

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Cool. Thanks for clarifying! I’m curious what fiasp would look like IM and IV. I might try IM for a real deal high but I dont think I’d ever try IV myself

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@Nickyghaleb thanks for the info on IM. Do you find it difficult to correct with a sliding scale after an IM? Obviously I am assuming you are ignoring the recommendation the pump is giving you off of BS.
@Larissaw - I have used Novolog, Humalog, and Regular all IV and my times are all the same - 5 min to see a rapid drop starting on a meter (between 7-10 with CGM) and clearing the body in an hour. DO NOT EVER do this with NPH! A basic rule of pharmacology is that if a solution is cloudy, it doesn’t go directly in the bloodstream (and there are always exceptions, but you triple check before putting cloudy meds in).
I have no issue worrying about doing it away from home amd nasty infections. What I am careful about is that the vial I am pulling from is clean, that the skin is clean, and that the needle is sterile / new (I have been known to reuse a needle for Sub Q - sshhh I know I’m a bad diabetic, but I am old enough to remember many people using non disposable needles without killing themselves). If it’s an old bottle where things may have gotten in their and had a chance to culture or I’ve dropped it on a dirty floor, I will just break open a new one.
I almost never pump bolus (and that drives the endo nuts :slight_smile:) because I find I get much better and more even absorption of the basal insulin at the infusion set insertion site.
I also have to agree that it is nearly impossible to do IV with the short needles. I won’t get anything less than 1/2" needles. The first time I saw the 5/16" needle, I threw it away - I thought there was a problem at the factory. It wasn’t until I uncapped the 3rd one that I finally read the box.
I generally don’t do IV as a meal bolus but certainly after this I think I will try IM meal boluses. Corn is my clear exception. If I eat a meal that is corn based, I know my BS will immediately skyrocket, and I will do an IV meal bolus. I swear I can eat cake and ice cream and my BS is lower than I corn tortillas!
I think @Eric has the best IM site plan with the calf. In theory, whenever you are moving your leg both thigh and calf muscles will be engaged, and 1/2" needles are certainly likely to hit the muscle in the calf.

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I was just talking about Fiasp through IM with a friend, and, if I remember correctly, it’s not supposed to act any differently. I’ll have to go ask why… And maybe try it. I think it would have to be a very convincing explanation before I ever tried a Fiasp IV though. That’s a little scary.

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Fiasp is Vit B3 and Novolog mixed right? I know B3 is a vitamin given in IV vitamin treatments.

Nope… or at least not that I’ve noticed. And, yes, I’ve learned to ignore the pump recommended anything. I was very fortunate to have found FUD and @Eric, and I learned how to… I don’t know… depend on my own calculations and guesstimates rather than relying on the pump’s. It’s working out great.

Interesting. I never looked any sooner than 10 minutes following the shot. I’ll have to try it again starting with 5. And you honestly see a CGM change within 7-10 minutes?? That’s impressive. What’s your CGM??

I went ahead and added in a bit of my own paranoia here. It’s kind of silly to be like that, and yet I’ve stuck with the rule.

I keep a designated IV vial, wipe it down with an alcohol wipe before every use, clean the skin, and use a new needle. Those things were drilled into my head as necessities.

I had a hunch I was a bad diabetic already, but if this is evidence… :grimacing:

A 1/2 inch for an IV… hmmm… I’m really going to have to think this one over. I actually use the 5/16, but I can have some difficulty with good placement. Maybe that’s why. But… you did also say the answer was 1/2… so maybe I’d rather keep having problems with placement. :thinking: Those needles are intimidating for IM… I think I’d pass out for IV.

I will do a pump bolus when I’m either way ahead on insulin or when I’m just too lazy to do anything else. I like the IM as a meal bolus. IV no… better as a rescue.

I will say about this that I stopped doing calves for IM shots because I hit a nerve twice. I don’t think it’s the end of the world, but I really didn’t like how it felt. Thigh and shoulder are my spots now, but I’m sure I’ll get over the calf thing sooner or later. I do massage the muscle when I do it, or I use the muscle.

Thank you again for the post. This has been very interesting. :slightly_smiling_face:


@Nickyghaleb I should clarify - certainly don’t insert the full 1/2" for IV, BUT the lower angle/having the top end of the syringe closer to the skin is the big advantage as I see it.

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I can also say that I have never had an infection from any injection. I CAN’T say the same about infusion set insertion sites :slightly_frowning_face:

I use the minimed guardian. I just can’t use a freestyle or a dexcom. Don’t get me wrong, I certainly have issues with minimed since medtronic bought them, but I find them less reprehensible than the crap dexacom and abbot try to pull (but that’s really a different thread).