FIASP for Insulin Pumps


I have been back on Novolog for a few days now, and I can say that I do NOT like Novolog compared to Fiasp.
I have more problems with lows on Novolog, which was why I raised my target from 100 to 110.
I will have more Fiasp (sample vials are great!) today I hope, and I ordered from DiscountRX for my longer term needs.
I didn’t have problems running the Fiasp out to 4 days (more like 3.5 days.) So, for me, I didn’t have a day limit on the sites. I did have a few sites that didn’t work as good though. More like Novolog reaction times instead of fiasp reaction times.


I’m not sure why, but that’s just what I’ve narrowed down thru process of elimination. Glad your fiasp experience is going well!


I didn’t find Fiasp a success in the pump, but I used my remaining supply for injected corrections and in situations where it was inconvenient to do a super-bolus. It was useful for that, but overall not, in my experience, the miracle drug I’d hoped for. Glad others have a better experience!


Just to clarify, were you finding it was starting to “fade” in effectiveness on the third day?


Yes, exactly.


What duration setting is everyone using for Fiasp in the pump?


Same as I did with Humalog, 4,5 hours. For me the tail is still there and I don’t want my boluses to mess up my basal.


I have mine at 3.5 hours. Thinking I might push it to 3.75 hours.


My pump is set to 3.5 hours, too, because that is what I’ve found works well for me with Apidra. The Vibe only lets me change duration in 30-min intervals, so I didn’t change it when I tried Fiasp.

That said, I did NOT have any lows while on Fiasp – just the feeling that I was low during the last (hour?) of the tail period after a larger bolus. I’m not sure if changing the duration would have helped with that issue…

(… meanwhile, Fiasp is still working great for me as an adjunct for corrections…)


Well, a few days on Novolog, and now back on Fiasp.
I can FEEL the difference between the two insulins.

I spent a lot of the last few days with higher BG than usual, and it did NOT want to come down.

Funny thing about Fiasp, I think that my basal rates were a lot more stable. Even though I could not eat with either insulin and stay fairly flat, the fiasp didn’t seem to flutter around as much as Novolog does.


I’m just on day six pumping FiASP and seeing good-to-great results. I agree that it seems to be making my basal more stable. I’ve been struggling with morning BGs that want to stay higher than I’d like and rising all the way to lunch, but I’ve been consistently seeing 80-100, which is really remarkable for me. Makes pre-bolusing a lot easier when you’re starting out from ~90 instead of ~140. And I have now officially stopped a Chinese dinner and a pizza dinner spike in their tracks. It was a flatbread pizza, but still. I actually peaked around 130 both times, which is unheard of. Also went kinda low after, both times, so it was a bit of an overshoot, but I usually have to do that just to keep from going too far into the 200s with those meals, so I’m very pleased with that.

I also agree that it “feels” different, but that will acclimate out I’m sure.


Be wary of pre-boluses. I had one in particular drop me like a ROCK. I bolus for eating when I start eating, and that does well. If I know I am having something like pizza, I will bolus a few minutes ahead. (unless my BG is already high.)


Hi, I’ve been using Fiasp in my pump since July 2017.
My findings have always been to split meal bolus’s the action of Fiasp it tends to leave me higher than I would want if I don’t do so.

For me an 80/20 split over two hours seems to be the magic formula!
Bolus for me needs to be done just before I eat any sooner and a hypo is guaranteed.
Duration seems to be 4.5 hours.


Second week on Fiasp for me. Before this I’ve been tending to drift high throughout the a.m. and pre-bolusing like an hour before lunch, like a struggle to get it to do much of anything, spiking in the 200+ neighborhood after lunch and then plunging later on. Yuck. With Fiasp I’m in the 90-100 range all morning, post-prandials topping out 160-ish, or even 140, and not crashing from my evening bike ride. I love this stuff.

The only problem I’m having is getting my hands on the stuff. I do the single-copay for 90-day prescription thing, but they only want to give it out in 30-day allotments. Had a lot of struggles getting it set up, and nobody has any on hand, so my last reservoir was running out when I finally got my scrip filled.

ETA: I’ve actually been thinking maybe I should give auto-mode on the 670G another try with this stuff.


Would love to hear how the auto mode works with the fiasp.
I can’t wait until Tandem implements it’s Control-IQ to do even more fun stuff.


Have you asked your doctor to share some of the free samples big-pharma is pumping out to all the prescribers? I’d call the doctor’s office and just ask! There’s no better price than free.


Yup, usually you only have to ask them.


I didn’t read the entire thread, but I will give my input with regards to fiasp. I use it in my pump (I’m European - Danish), and I would say it’s perfectly fine to use in a pump - it’s not like we are crazy irresponsible over here, so I don’t believe doctors should be too worried to try it out in pumps for fear of harming their patients. :stuck_out_tongue:

Anyway, first I want to say don’t have too high hopes, like I did. It will likely disappoint if you do.

It wasn’t as easy to switch as I expected it to be, but it does what it says for me. I needed to adjust my insulin sensitivity and insulin-carb ratio (I need more insulin to cover it), but my basal is the same. I also had to change the “active time” of the insulin in my pump from 4 hours to 3 hours. I don’t have to wait 30 minutes before eating, and I can now eat fruits or high fiber rye bread without a spike.

I absolutely recommend keeping a food journal and weighing everything you eat and calculating the carbs as precisely as you can, to figure out the correct ratios, as it most likely won’t be the same.

Fiasp works well with the “Guardian System” (Enlite sensor link) in the MiniMed 640G pumps, because it doesn’t last as long as other insulins. So when it shuts off the basal, your BG will rise faster (from my experience).

For me it stings at bit when bolusing, and can cause lingering local irritation after changing site (a small lump under the skin), and can cause local insulin resistence after 3 days. From my understanding it’s the vitamin B3 that paradoxically does that. It’s the reason why it works faster, but high doses of B3 causes insulin resistence as well. There isn’t enough B3 in the insulin to cause systemic insulin resistence, but can cause local resistence.

When eating high fat meals with carbs (pizza for example), you will probably need to take an extended bolus to cover the carbs, or you will go low before all the carbs are absorbed.

It works very fast in intra-muscular injections. Impressively fast to be honest. If I’m going back to NovoRapid in the pump, I will still keep fiasp as a supplement with manual injections for meals with fast acting carbs. I haven’t really decided if I’m going to stick with fiasp in the pump or go back to NovoRapid. I just like the freedom of not having to wait a very long time before eating, lest I suffer a spike in BG. :stuck_out_tongue:

I think I remembered everything I wanted to say… If not, I will edit the post. :slight_smile:


It’s been month since I started FIASP and it is been wonderful. Novolog bolus and basal were a good starting point for FIASP. With Novolog, I had manipulated basal rates and carb ratios to keep post prandial spikes under control. Don’t need that so much any more. Active insulin time went from 3 hours, which was too short, to 2.5 hours. The straight line IOB decay on Medtronics pumps seems to be reasonable with FIASP. The hypos I do get are a whole lot easier to treat.

With vacation, insulin change and weight loss, change to pre-bolus time is a little less certain. Novolog was 40-45 minutes and often that wasn’t enough. With FIASP needed pre-bolus time is down to 20-30 minutes dependent on BG and meal/time of day. FIASP pre-bolus times are still a work in progress.

BG/SGs are a whole lot more predictable than with Novolog. This is probably due to less stacking with the shorter tail and more reasonable IOBs.


I’m a tad confused by your active insulin, are you saying you have your duration set at 2.5 hours?

The leaflet with Fiasp states inject 2 mins before meals or up to 20 mins after starting the meal.
The maximum effect lasts between 1 - 3 hours and the effect lasts from 3 - 5 hours.

As I understand it the duration is the same as novo or am I wrong in thinking this?