FIASP for Insulin Pumps


All down also had to change carb ratio from 1-11 to 1-14 lunch time and evening meal from 1-12 to 1 -13.

I took almost 5 units off of my basal.

Correction from 1 unit dropped me by 5.5 to 1 unit dropping me by 6mmol.
Insulin duration set at 5 hours

A1c is exactly the same @ 6.4% I’ve been on Fiasp since July 2017.

Hope that helps


What was your Insulation Duration prior to Fiasp (assuming same pump?).

We made a significant reduction in our insulin duration from 4-1/2 hrs down to 2-1/2 hrs.


I know some people don’t agree with this but I believe, given the same level of blood glucose control, less insulin is better than more. Good job on your Fiasp insulin adjustments.

I took a look a the Fiasp package insert to see what it said about insulin duration. Looks like they show insulin duration at 5-7 hours depending on how many units/kilogram of body weight that you dose. Here is a snap-shot of their findings for their study group.

I don’t use Fiasp, but I have increased my Apidra duration of insulin action setting up to 6 hours influenced by this NIH John Walsh study entitled Confusion Regarding the Duration of Insulin Action. I had previously used settings as low as three hours.

The people who maintain the code that runs Loop, an automated insulin delivery system, recommended setting this option to 6 hours. I think my overall control is improved with this setting change as I don’t get many blood glucose surprises several hours after a meal.

Having said all that, I’m a firm believer in the saying, “what works, works.” We do not all align with the norm of the people studied to produce the insulin duration graphs.


The problem with these drug company studies though, at least from my perspective, is that they are based on large doses of insulin. For me 0.1u of insulin per kg would be a very large and rare dose. I usually inject 0.04 u/kg or less depending on what I’m eating, and when I tried Fiasp I found it was basically gone after 2-2.5 hours.


Quite similar here. If the BG is not where we want it 2.5 hours after a Bolus then it is not coming down any further. Time to dose again.
This would be different from Novolog / Humalog where we would wait for 3 to 4 hours before doing a re-dose.

Often times we will even do another Fiasp dose after 1-1/2 hours if we do not see the movement we expect.

Clearly it reacts different for different people. But for us, it really kicks in super fast and the main action is over and done in a surprisingly short time frame.

We are still new to Fiasp only having gone through six vials so far. Some people have mentioned that the action changes over time so we have yet to find out whether that would be a factor for us or not.


I had to pull out a conversion app to see what our KG would come out to.
So also similar for us. .1 unit/kg would be a good sized dose. Not crazy but not the most typical. Maybe for a high (>250) correction bolus. For a regular meal bolus (with no simultaneous correction) it would more likely be in the .05 unit/kg range.

A 0.4 unit/kg bolus (for us) would certainly require Glucagon.


I’m also in the vicinity of 0.05 IU/kg for bolus, depending on the time of day and how many carb’s I’ll be eating.

I have my active insulin time set to 2 1/2 hrs. Active insulin seems to be a decent match with FIASP. So I’ll do a supplemental correction in as little as 45 minutes if BG excursion continues. If BG ends up low, then its just a few carbs. Correcting a low is a whole lot easier than bringing down a stubborn high.


I’ve given up on Fisasp for the time being. No question my postprandial numbers were better than with Humalog but too many unexplained highs and too much time spent trying to figure out why (change infusion site, etc.). Most are due to the apparent problems when the reservoir volume is low with T:slim pump and it’s become a real hassle. I see my endo next month, I’ll see what this has done to my A1c and I’ll review all this with him. Maybe I’ll give it another shot if he has ideas.

I looked again at Novo’s clinical trials for Fiasp with pumps. They finished two phase 3 studies in July 2017 comparing with NovoRapid. The raw results are available for both, but only one has published results with analysis and conclusions. That one looked at infusion site occlusion as the primary outcome and the conclusion was there was no statistical difference. A much larger study compared changes in A1c as primary outcome and many other secondary outcomes.

To my non-expert eyes it doesn’t look like there were any issues with Fiasp in these trials but all this was with Minimed pumps. A “fly on the wall” at Novo told me they hope to have Fiasp approved for pumps in 2019. That makes sense given two completed phase 3 trials.

If anyone’s interested they have a trial in the recruiting phase looking at Fiasp and 670G hybrid closed loop system.

If you’re really bored you can look at


I’ve now used 5 vials of FIASP in my Tandem t:Flex pump, switching from Novolog. I also use a DexCom CGM. Some really interesting results/observations:

  1. I have no pump/infusion set problems for the first half of a reservoir full (~480 units). But 100% of the time, I get occlusion alarms as soon as I’m in the last half of the tank. Changing to only loading ~300 units in the cartridge has completely fixed this. Since doing this, no infusion set problems at all. Before finding this fix, I was ready to quit FIASP. Now I just use twice as many cartridges and infusion sets.
  2. As far as use of FIASP in the pump, I have had really good results. I’m a pretty bad diabetic, as I usually don’t do my bolus until I’m at least halfway through my meal. With FIASP, my meal highs are down by about 40 points. I see a fairly quick downturn in BG (about 20 minutes) and then it levels off for about 1-1/2 hours, when it starts a steady downward movement.
  3. My insulin duration is the same as with Novolog.
  4. I use about 20% less FIASP than Novolog for a similar meal. As an aside, my use of Novolog is about 50% of what I needed with Humalog.
  5. FIASP does better with minor excursions from normal BG than when I need to make a big corrections.
  6. I’m on Medicare, and yesterday I ordered my first refill of FIASP. Last month, the pharmacy filled it no problems under Part B. Today, I’m told that via email it’s not covered by my insurance. Of course I don’t know whether Walgreens tried to run it through Part B or Part D. They usually do it wrong, and I have to make two trips there to get insulin, one to staighten out the insurance problem and then go back after they fix it with the main office to pick up the stuff. Apparently in my neck of the woods, there aren’t too many on a pump, so they keep trying to charge me $3500 a month for my 5 vials.


I am on my third vial of Fiasp in my Medtronic 670G. I reduced the Insulin on board time from 3:30 for Novalog Down to 3:15 for Fiasp. So far, I have reduced the height and length of my post meal spikes and my 30 day blood sugar average is down from 156 to 146.

I ordered 9 vials for three months from Caremark using my United Healthcare Medicare Group Advantage (Silverscript) Plan at a cost of $50.


According to the official documentation, Fiasp doesn’t have a shorter duration of action (tail), it only has a shorter onset of action.

But I changed my duration of insulin action from 4.0-4.5 hours to 3.0 hours when I switched from Apidra to Fiasp. So for some, it seems that it does have a shorter duration of action.

I find that, particularly when I catch a high that’s trending up and not yet high, a tiny bolus of 0.25 to 0.5 units of Fiasp seems to work virtually instantly. Larger boluses (especially when high) can take longer to kick in, but it’s still much faster than Apidra or Humalog was for me.


Hi. I was wondering? How do you like the Tandem pump? I am not due for a new pump until 2021 and I am interested in the tslim. I heard that the cartridge/site change is a little difficult. Right now I am using medtronic’s 630 pump.


I definitely think if this is likely to be concerning then it is much better to stick with what you have.

I absolutely 100% guarantee that when you switch from Medtronic to Tandem, there will be numerous changes and differences you will find.

There is nothing wrong with staying with something that you have spent a long time becoming familiar with. You can probably do the vast majority of operations without even thinking two thoughts. It becomes second nature. There are clear benefits with that.

Choice is good.


I absolutely love the t:Slim X2 Pump for a lot of reasons. I can’t really draw a direct comparison with the Medtronic pump as I had a run-in with them with my first pump (because it wasn’t waterproof) and I moved to Animas. When Animas decided to get out of the pump business they tried pushing the users to Medtronic but I did my own thing and went to the t:Slim and haven’t regretted it a minute.

Here are some of the reasons I really like the t:Slim X2:

  1. The pump is user updateable. I hated the fact that, once I went with a pump, I was locked in on that capability for 4 years while the industry was progressing. I have already gone through one user update and it was very easy and added significant capability to the X2… They call it Basil IQ

  2. With the new update, it is integrated with the Dexcom G6 CGM Transmitter/Sensors. With this system there is zero calibrations needed… no more finger pricks to calibrate the system. I used Dexcom with the Animas pump as well and feel that they are far ahead of everybody else on CGM accuracy

  3. With the Dexcom G6, I can also get my CGM readings on my Android Phone (also works wit iPhone). It is super convenient to glance at the phone to know your BG readings, which is probably already in my hand, than to the access it via the pump… Although it is also super easy to view it on the pump as well since you don’t even have to unlock the pump in order to see the CGM.

  4. I like the color touch screen. It just makes the t:Slim X2 more like any other mobile device rather than a clunky medical device.

  5. I’m not sure what you are saying about the site change being more difficult. I like the fact that the infusion set and inserter are made together. From what I remember about the Medtronic, you had to have a separate “inserter” device which you used for the infusion sets. Just like Medtronic, there are a number of choices of 90-degree, slanted, soft canula, metal canula, and etc.

  6. Probably the biggest thing from a BG management standpoint is that you can do multiple basil programs (Tandem calls them “Profiles”) throughout the day and those profiles can also have unique Basil Rates, Correction Factors (how much BG is lowered by a single unit), Carb Ratios (number of carbs per unit), and even target BG. Each time entry in the profile can have different values for each of these. While this may seem like overkill to many, I’m a control freak and love having that much flexibility. It allows me to really manage the variations to how my body works at different times of the day. Since being on the t:Slim X2, my A1C has been ranging in the mid to high 5s where before it was more in the mid 6s… Pretty amazing for a Type 1.

This may have been more information than you were actually after and I don’t know how to really draw a direct comparison to the Medtronic 630 but, based on what I hear from my endocrinologist, the t:Slim with Dexcom G6 is a much better CGM than Medtronic… And the majority of their patients are Medtronic.

One last thing. Since you were responding to a post I had made in the “Fiasp” thread, I dscovered that it was the soft canula on the infusion set I was using that was causing the issues with Fiasp site longevity. I moved to the metal canula infusion set and the Fiasp is working much better. Even though my insurance doesn’t cover Fiasp and I’m having to get it through a pharmacy in Canada, I believe Fisap has also been significant contributor to beig able to significantly lower my A1C. It has such a fast action time that I don’t have the big post meal spikes I used to have.

Hope this helps.

Regards, Steve Yarbrough


I’ve been on a pump for about 20 years, and have tried just about every one except the Omnipod. My current pump is the Tandem t:Flex, which has been discontinued. Before that, it was the Medtronic. My next one will definitely be the t:Slim X2. I like the company, the customer service, and if I have to be diabetic, I like the t:Slim best to handle my needs.

The cartridge fill process is a little clumsy but after 2-3 times you’ll have it down pat. The tubing fill is pretty fast. Overall a good pump.


Because it is able to be updated is one of the reasons why I want the Tandem pump. I also like the fact that you don’t need to buy batteries.I didn’t like medtronics cgm. I found that the sensors are supposed to go 6 days but the on the fifth day accuracy was bad. I too, was on the animas vibe with dexcom g4. I have been using dexcom g5 with my medtronic pump. I am already using the Tandem 90’s for my infusionsets. I also like the fact that it is a touch screen and you can add your carbs on it. I also have been using fiasp for the last 6 months and I love it. It is able to bring my sugar on the down trend usually in about 10 minutes when I watch the cgm. I am in Canada so by 2021 Tandem should have their automated system by then.


Based on your update, I think you will love the Tandem Pump. I have found Fiasp to be a game changer. That’s why I’m now paying $600 for a 3 month supply for Fiasp (through Canada) vs my insurance coverage for Humalog at $90 for a 3 months’ supply.

Regards, Steve Yarbrough


I guess I’m fortunate to have my husband’s medical insurance through his work. We just recently got them to cover 3,000$ of my dexcom sensors and transmitters.


I am still LOVING Fiasp in my X2 pump with G6 and Basal-IQ.
I almost did the 670 pump, but felt the X2 was easier to use.
I really didn’t think that the cartridge refill was that much of a big deal. I don’t have problems doing it.
But, I wasn’t doing it for years a different way, then having to change.
I still have to get Fiasp from a Canadian pharmacy that I pay out of pocket because the VA still doesn’t carry it.


I have finally gotten to try this insulin (since my endo insisted it was the same thing as Apidra and was unwilling to let me try it, I asked my primary care to fill a prescription for it). So far so good. I am on my second day with it and I haven’t had any issues. I have not experienced any site irritation, which is an interesting change from Humalog which I have been on since being diagnosed 20+ years ago and was causing me more and more irritation and was starting to not work effectively.

Two things I have noticed so far are that my waking BG is higher (though that has always been hard to fix for me), and that it does seem to work faster. My BG hasn’t quite been in range, but it has been more stable even with food, so that is a definite plus.