Fiasp® (Faster-acting Insulin ASParte) is a new formulation of NovoLog®, in which the addition of niacinamide (vitamin B3) helps to increase the speed of the initial insulin absorption, resulting in an onset of appearance in the blood in approximately 2.5 minutes.  According to Novo Nordisk, Fiasp, “has its maximum effect between 1 and 3 hours after the injection and the effect lasts for 3 to 5 hours.”

It is not yet rated for use in an insulin pump and was just approved by the FDA for sale in the US. The US price for the pen cartridge is not available yet and I hear that availability will be first quarter 2018, although I’m sure there will be prior authorization issues.

It’s REALLY fast!  I’ve been using Fiasp, in my Medtronic 723 pump with the do-it-yourself RileyLink closed loop system, since I was able to import it from Canada (thanks to the great folks on the Facebook group, Looped) about 3 weeks ago. And I am amazed.  My husband is amazed.  My endocrinologist is amazed.  I frequently look at my 24-hour Dexcom chart and smile. 

While I am not the greatest at the technical settings and making adjustments, I’ve noticed that my total daily dose of insulin is down about 25% and I routinely reduce my recommended bolus by half. I know I have to make changes in my ISF and I:C ratio. 

I had read about issues on

  • Worked well for a couple of weeks, then ISF plummeted so TDD went up
  • Worked well for a while, then started getting major site inflammation/irritation problems
  • Worked well for a while and but needed a lot more basal
  • Worked well for a while but then had to use more insulin per gram carbs

Loopers had a wide range of experiences, as above … no one T1’s experience was exactly like any others.

So far, my experience is all positive.  I have no irritability at the site, don’t need more basal at all and maybe noticing that my insulin sensitivity is inching back.  But overall, I couldn’t be happier!

I do feel a sense of anger though! 

Why did it take SO long to get a faster acting insulin??? I’ve been using insulin for over 50 years … this should have been here a LONG time ago! 

I hear that the pricing for Novo Nordisk Fiasp will be similar or a bit higher than Novolog.  That’s NOT ok!  I’ll continue to purchase from Canada!

Want to learn more?  Tim Street writes all about his experiences with Fiasp on his blog,, “Where Diabetes and Technology meet.”  Outstanding information!

Any questions?  I’ll try to answer or find out from others.  For now, I give Fiasp A+++++!

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