FIASP for Insulin Pumps

Into week 2 using FiASP, mixed 50/50 with Humalog to test faster onset with longer duration. As expected, not nearly as immediate BG response as with 100% FiASP - perhaps also what others mentioned above that the body develops some sort of resistance to the quick onset.

Overall quite happy with 50/50 FiASP / Humalog - it does blend the benefits of both :+1:t3:

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I did mix once and I noticed a big negative difference. Mainly that the extra irritation I have from Humalog and the poor absorption after about a day. The only negative issue I have had with FIASP so far has been the more frequent site leaks which seem completely unexplainable.

I’ve been using an 80/20 FiASP/Humalog mix for a few months because of the pump problems I had with 100% FiASP. I no longer have pump issues when the cartridge level gets low. I don’t have any quantifiable way to measure if the absorption speed is worse than FiASP alone, but I think it’s closer to FiASP.

My concern with mixing is that the active ingredients that facilitate faster absorption (niacinamide and L-arginine) are diluted proportional to the mixing ratio. I don’t know how the effectiveness falls off as the concentration decreases. I’m sure Novo formulated FiASP with this data in hand. Maybe it’s proportional or maybe there’s a minimum concentration required and Novo added this plus a buffer? That’s why I diluted the FiASP just enough to eliminate the pump issues. But it looks like you’re using it successfully at a 50/50 ratio so I may give that a try. My pharmacy charges a premium for FiSAP so I’ll save money!

I wonder whether using Novolg instead of Humalog, so there is only one type of insulin in the mix, would have any advanatages?

My rationale for the 50/50 FiASP Humalog mix was to mitigate the need for using considerably more total daily (FiASP) dose than what I used for Humalog.

This is only day 2 on the 50/50 so the jury is still out, I’ll post TDD used for FiASP vs Humalog in a couple of days :+1:t4:

Interestingly enough for me I have been using significantly less insulin with Fiasp.


I don’t know if it is “advanced” paperwork, but there are some fairly simple rules the endo has to follow to get the pump for you. I think there’s a Certificate of Medical Necessity or some such form where he says you have diabetes and are doing multiple daily injections, you are having frequent highs or lows anyway, etc. The rules are published on most pump company web sites. I’ve had a pump for about 20 years and never had a problem getting either a pump or the supplies for it covered by Part B. The only problem is at my local Walgreens where apparently no one else uses a pump, so they always try to put the insulin under Part D. So I’ve just gotten used to going there in person to order each refill so I can remind them about Part B.

If you’re still not on Medicare and you have a good employer plan, it might be a good idea to try to get the pump before going on M’care.


Thanks. I’ll only have 2-3 months left on Tricare (military retiree) when my Medtronics pump comes off warranty. Tricare is rent/purchase over 13 months.

I know my CPAP machine was a rent-to-own deal under Medicare, but I don’t remember my pump to be that way. With 2-3 months before pump replacement, I think you’ll find yourself in a timing situation. I always start my pump replacement process with my endo about 3 months before the warranty runs out, to get all if the questions answered, the back-and-forth correspondence, etc. done, so I can expect to get the pump by about a month or so after the warranty runs out. You probably should expect to use your old, out-of-warranty pump for 3-4 months after you get onto Medicare to allow for the wheels to grind slowly processing your order. But the pump companies are usually very helpful to get those wheels greased as much as possible. I know Tandem was, and wY back maybe 10 years ago, so was Medtronics.



Interesting new article on this subject.

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Well, after using Fiasp for a while and switching back to Novolog, I can say that for ME, it is absolutely worth it!
It is not perfect by any means, but the end results far outweigh any negatives.


They do seem to be leaning really heavily on the negative comments and findings. Not sure why—it certainly doesn’t match my experience with it. I had a couple of incidents of the sting/red-spot thing, but seems to have been isolated and temporary, not a chronic problem. The only issue I would warn people about is that if you’re bolusing for a meal with a lot of fat content, thus slowing the rate of carb absorption, Fiasp can end up coming on a bit too fast. I had that happen once with pizza (the dread pizza, sheesh). But other than that it has been great for me.


This is different person to person.

I know for some people it is enough to completely make Fiasp unusable for them. For others, they may not have the reported issues but also they might not see any speed difference.

I would suggest that anybody who wants to use Fiasp should get a trial or start with 1 or 2 vials. Definitely not jump right into a 90-day supply and then find out it might not work for them.

We have none of the reported issues and find it works very good. For us. We would not willingly go back to Humalog or Novolog.


Totally agree–that’s what I did. And of course no one regimen is good for everyone. I just find it confusing that the artcile chooses to focus so relentlessly on the negative.

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I think that’s one of the key take-aways from the article and the comments in this string. They talk about the negative issues for some, but not all, patients.

I’ve never experienced any of the pain or site irritation issues, but was consistently having unexplained episodes of high blood sugar. I wasn’t able to resolve this until I diluted the Fiasp to U80 using either humalog or humalog diluent. But after that change I’m very happy with it’s performance,

I’m anxious to try Lilly’s Ultra Rapid Acting Lispro when (and if) it becomes available in the US. Just like Fiasp it has two additives (citrate and treprostinil). These are different than to two used in Fiasp. The other nice thing is the clinical trials used pumps.

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I’m a little suspicious of “…although there is little data available regarding its clinical utility in insulin pumps.” FIASP was approved in Europe for use in pumps before FDA approval of FIASP.

Early on, I had occlusion warnings with 2-3 infusion sets/sites. FIASP was delivered with tubing detached, so the problem was either in catheter or with the site. No problems since. My site problems have been no worse than with Novolog.

I will say I know of at least one other Fiasp study not mentioned at the bottom of the article; one I saw on a local Endo website for studies they were participating in. It was to compare the speed of plateauing of rapidly rising BG with Fiasp compared to Humalog/Novolog.

I have mixed feelings of Fiasp after using it for a while now. The site irritations are not much different, if at all from Humalog, so that doesn’t bother me. Sites do seem to last a little longer than on Humalog, but not reliable enough to call it a complete win. I have only had one occlusion so far, and it was a clog in the tube/cartridge somewhere. I can’t say for certain it was the insulin’s fault. It seems to lose a lot of effectiveness after about 2.5-3 days for me, and I do think the occlusion was past the 3 day mark. It does seem to work a little faster than Humalog, but it has not been working nearly as fast as it did when I first started using it. I used to get the double down arrows on the CGM sometimes, but now the fastest I get is usually a sloping arrow.

Though I have not had the consistent improvements over Humalog I had hoped, I am probably going to stick with it because it is actually a little cheaper for me surprisingly.

That is interesting, I have not heard of that one, though I suppose it shouldn’t be too much of a surprise that they would be making one. I’m sure Sanofi will be as well.

I’ve been on it for a year and love it. As already mentioned above, my major changes have been A. be mindful of high fat content foods and when to bolus and B. being more thoughtful in my workout planning routine to avoids lows, bc FIASP on board will drop me alot quicker than Novolog or Humolog.

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Funny, with Fiasp, my IOB will drop me for excercise, but I recover easily.
With Novolog though, I do NOT recover that well. I have to fight to get my BG to climb again.

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One thing I like about Fiasp in this respect is that I used to have the darnedest time getting a temp basal dialed in before exercise that would actually work. Seemed to require being set 2 hrs prior, which is kind of a pain on many levels, and then I’d either end up going low anyway (depending on time of day), or running high or whatever—getting it just right was totally elusive. With Fiasp, if I set a temp an hour ahead, it almost always does exactly what I want. Just seems like Novolog/Humalog would find some way to linger in my system just so it could kick in with exercise, whereas Fiasp really clears when it says it’s going to. That’s at least as big a benefit to me as the faster onset.

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I’ve noticed that too. Getting low with FiASP I’d best described as a soft low, not the sort of freight train low we’re used to with Humalog.