FIASP for Insulin Pumps

Terry, have you? How was it? Immediate onset? Do you use the same ISF for IM correction?

I’ve never used Fiasp but I do IM corrections with Apidra and it does seem to shorten onset and peak times. I find it an effective technique and I use once or twice per week. I do use the same ISF as other corrections.

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Where do you inject the IM? Arms?

I inject at the top of the arm into the deltoid muscle.

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Terry - How do you inject deep enough for IM? Are you using syringes with needles longer than insulin syringes?

I use the 12.7 mm (1/2 inch) 30 gauge insulin syringe. Dr. Bernstein explains that this depth will only just reach the muscle and the needle must penetrate at 90 degrees. Bersnstein also says it will not work if you have “fat” arms. More usual IM needle lengths are 1 - 1.5 inches long. I do observe faster insulin action when I do this so I assume I’m hitting muscle.

Here’s a Bernstein video talking about and demonstrating an IM shot.


IM seems to be 1 to 1 1/2" needle, depending on individual. So at 1/2’, the faster absorption might be due to getting closer to muscle and it’s more plentiful blood supply.

My infusion sets have the 6 mm canulas, so a 9 mm canula might speed up absorption with Novolog. That might risk true IM and absoprtion that is too fast, leading to hypo episodes. Something to add for discussion at my next endo appointment.

I’m struggling with problems similar to what many are describing here with Novolog: very long pre-bolusing time, like an hour to an hour-and-a-half, and long, persistent post-prandial spikes from relatively moderate carbs because it’s so hard to get the insulin going early enough. Biggest issue for me is that I generally have what carbs I’m going to have for the day at lunch time, so that’s when I’m going to spike, but then I have some endogenous insulin production that kicks in like clockwork from about 5pm-6:30pm, which is when I’m bike-commuting home, or going for an exercise ride on weeknights (just the most convenient time for me in all other respects). So the result is that I’m having to either accept having my BG hovering in the ~200 range most of the afternoon in order for it to be high enough to ride home, or if it has gotten really north of 200, struggling to figure out how to correct it without ending up with 50s and flashbulb effects in my eyes when I get home from my commute.

This pattern was one of the things I was really hoping the 670G was going to help with, but it just didn’t, and I think the limiting factor was not the algorithm but the effect curve of the insulins most of us are using now. There’s just no way an algorithm can be more rapidly responsive than the insulin it’s given to work with.

Clearly rapid effect and shorter tail is what I need, and I’ve just been been in touch with my Endo about maybe seeing if Afrezza would help me solve this longstanding quandary, and she’s willing, but she and my DBE (who’s really sharp and a T1 himself) came back with the suggestion that I try FiASP first. I’m seeing some encouraging posts here from @Hammer, @Jen, @SLYDoggie, and others, but it’s been a few weeks since anyone has posted so I thought I’d bump this one up again. I’d really like to hear more about how it’s going for people.

Re site-longevity and irritation issues, which appear to be thankfully not universal but pretty common: has anyone tried staying with Novolog in their pump for basal needs but bolusing with FiASP with an injector?

I’m just curious, how do you know you have insulin production at this time (or at all)? It seems odd that insulin production would kick in at the same time every day. Could this be a basal issue? Have you fasted through lunch to see? Or even just eaten a lower-carb lunch? Or tried suspending your pump an hour or two before this time?

Interestingly, with Apidra I had this same type of thing happen every day for two years. On my commute home I’d drop low almost every day unless I ran a temporary basal rate starting an hour or so before I left work. (And I don’t produce any insulin to my knowledge, though I’ve never been tested.) With Fiasp, while I can’t say that this never happens anymore, it’s gone from nearly 100% of the time to about 25% of the time. Though it’s hard to tell if this is because of Fiasp or whether it’s because I’m eating pretty low-carb these days (about 30 grams a day).

I don’t notice any site issues whatsoever when doing an injection, even with fairly large doses. To me a big part of the advantage of a pump is using the touch/audio bolus button while it’s in my pocket, so I wouldn’t want to inject for every dose (I bolus probably ten times throughout the day on average), but I do inject fairly often: if I want to do an IM (Fiasp by IM is amazing, by the way!), if I’m over 10 mmol/L, if I think my pump isn’t working, or if I want to do a large bolus of, say, 20 units for some reason (probably because I’m having a rare carb-fest) that I want to divide up into different injection sites.


I’m still having excellent results with Fiasp. I use it in my pump for both basil and bolus. On Humalog it was not unusual for me to spike at 250 to 300 after lunch if I didn’t bolus in advance. With Fiasp, I don’t have those spikes. I did have to play around with my pump Basil and Bolus rates and had to cut both back a bit. In my case, Fiasp just works better for me all around.

My biggest issue is that Fiasp isn’t on my insurance formulary and the cheapest I can find Fiasp is $289 a vial… Ouch. I’m considering ordering through Mark’s Marine Pharmacy in Canada where Fiasp is $70 a vial and hope that it gets added to the formulary during the mid year formulary adjustment my insurance company does.


Yeah, it’s weird but I’ve always tended to drop right in that time period, irrespective of treatment regimen, even back when I was on R/NPH in the 80s-90s. I’ve always thought of it as kind of the evil counterpart of DP, like my body starts expecting dinner and squeezes out whatever insulin it’s got. It would suit me a lot better if it would kick in at around 5-7 am instead. My current endo is the one who suggested it might be endogenous insulin, and she credits it for my good control, though I wanna say it’s hard work too.

From what you describe it will be interesting to see whether FiASP affects it. I have tried using a temp basal a couple hours out if I know I’m going to be biking, and it does ameliorate the problem, but it’s hard to do that when I’m still looking at a really high BG and not absolutely sure what’s going to happen later. I generally eat low carb, but it’s harder to manage at lunch times–sandwiches are just such a convenient food format. It’s less of a problem if I zero out the midday carbs entirely, but partly this is a matter of principle. I spent decades conforming my life to my insulin rather than the other way around, and in this day and I age I feel like I should be able to manage a few carbs at lunch or occasionally at dinner without riding the spike-and-plummet rollercoaster.

Maybe you could move to a different time zone and test out your theory :grinning:

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I agree. Low-carb bread has been my solution to that. :slight_smile:

So… Beijing?

Weird thing is that officially the entire rest of China is on the same time zone. By the time you get to where I went for my brother’s wedding (near Mingshu in Yunnan), it’s so far off as to be widely ignored by everyone.

I thought it might be helpful to post images of a “typical” day on Fiasp vs. a “typical” day on Humalog. As you all know, there really isn’t any such thing as a “typical” day as it seems that every day is different so maybe “representative” would be a better term to use. In any case, I think you will get the gist of how Fiasp is working for me vs. Humalog. I’m posting 2 screen captures for each… The daily CGM curve from my Tandem t:slim X2 pump which also shows the pump calibrations. The “gap” on the Fiasp one is where I had to do my weekly CGM sensor change.

Here are the Humalog screen shots from Glooko Diasend reporting application:

Here are the Fiasp Screen shots from Glooko Diasend reporting application:


You can see from my basil rates for both Humalog and Fiasp, that I have a multi-tier basil program and have developed that changing rate over time based on my body’s need for basil insulin at various times of the day. I did have to tweak it for the Fiasp and that is why the blue line looks different on the two.

One thing to also note when viewing these is that I don’t eat breakfast. I found that breakfast would start me on a YoYo where I was chasing the ups and downs for the entire day. Now that I’m on Fiasp with significantly reduced post meal peaks, I may try to going back to eating breakfast. I’ve been on the “no breakfast” routine for several years now and I have the basil pretty well tuned so that things stay pretty flat until I do lunch… Usually between 11:00 and 11:30.

You will also notice one “oops” at the end of the day on the Fiasp day. I had a snack and over estimated the carbs and that drove me a bit low.

You will also notice that I was “chasing the high” on the Humalog day and had to do multiple correction boluses after dinner. I also did my boluses well in advance of eating lunch and dinner and still had the significant peaks with the Humalog.

As I have stated, Fiasp has been truly a game changer for me. It may be that my body physiology is just a good match for how Fiasp works and I may be the Fiasp poster child so your mileage may vary :slight_smile:



Is there any way you can split up your carbs a little, maybe a mid-morning and afternoon snacks? Since splitting my former breakfast between breakfast and an early morning snack abut 6 wks ago, I rarely have low/high BGs or stubborn highs before lunch. And my weight is down 7 lbs as that change has mostly eliminated high fat morning peanut butter snacks.

I couldn’t have made the change in my previous Air Force position. Supervisor wouldn’t have allowed and only for her own convenience.

I am on day 24 of Fiasp now.
I have still been trying to test it out on random foods.
I have found that I have made a few bad guesses… Oh well.
BUT, even those bad guesses have been FAR more controlled with Fiasp then Novolog.
I left all pump settings alone except time down to 3.5 hours. I am still using these settings, but I am thinking I might start lowering my daytime basals.
Right before starting Fiasp, I was about to raise my nighttime basals a little more. But now they seem pretty on target. Might even lower the basal a little around 4 to 5am.
Point is, because of the way it works, I will use less for my basals, which is a big win for me in many aspects.

Now, I have had some BIG meals. Like an entire large frozen pizza! First time I did it, I didn’t get it right, but all things considered, it went well. Second time, you would barely guessed I ate a few carbs!
I hit it harder, and hit with a second dose for fat/protein.

Two downsides for me.
First, it stings/burns sometimes when I bolus. Mainly larger boluses. I am not worried about this, as I don’t have a sight irratation issue. I have even left the sites in for 4 days a couple times now.
Second, I CANNOT pre-bolus! I did it once to make a correction and bolus before eating a somewhat higher carb lunch. Not a good idea! I dropped like a rock! Lessons learned is to only do the correction, then bolus when actually eating.


I might be weird, but I find some amount of comfort and/or peace of mind when I can feel the insulin going in from a bolus. I suppose it just helps me know that it is going in and not leaking or failing to absorb.

I am not really complaining about the sting/burn. But I thought it was worth mentioning for people that it would be an issue for.

Not a bad suggestion, though in my case I don’t actually eat breakfast as a rule–just coffee; a lifelong habit, hard to break.