My try of Fiasp

Fiasp is Novo Nordisk’s newest rapid insulin. It has two additives which are supposed to speed up its abortion - nicotinamide and arginine.

I got some Fiasp a few weeks ago and wanted to give my impressions on it so far…

Before saying anything, I want to point out, my bar for insulin speed is set pretty high. I mostly have been using Apidra for injections, which is a bit faster than either of the “logs” (Humalog / NovoLog). I also frequently do intramuscular injections, and use longer needles, so I am used to more rapid insulin absorption.

I know there is a lot of excitement about it and people are hoping for a faster response.

I would just say that people should temper their expectations a little bit. It is not a game-changer. :frowning: It seems perhaps a slight bit faster, but nothing that will rock your world.

I didn’t have any burning or pain from the injections like some have reported. I have only used it with syringes though, not a pump where some of the complaints have come from. And the insulin duration is the same as far as I can tell. I think getting rid of the 3-5 hour insulin lag would be the real game-changer…

So, for what it’s worth, a bit faster, that’s all. But if you want to try it, you should. From Canada, about $70 plus shipping gets a vial to your door.

(image taken from


That’s great to see you experiment with it!

I wonder how it would compare to our reaction time. It takes us 40 minutes to see significant Humalog/ Novolog action. I hope to be able to test it over summer.


Thanks for the information. Really interesting. I’d like to try and will, but doesn’t seem as promising as I thought it would be.

What length needle do you use for intramuscular injections?
I need SO much information and guidance!

I really want to try IM because faster onset makes so much sense! I even wish to consider IV (not there yet)


It depends a little on your body composition, but if you use a 8mm needle in the back of your calf you will likely be IM.


As Chris said, it depends on your body composition. But it also depends on the location of where you are doing the IM.

I would suggest trying from 8 mm to 12.7 mm (1/2 inch) needle length.

If you have had a flu shot, you know the place they do that in your shoulder. You can try IM there with a 1/2 inch needle. And as Chris said, the back of the calves is pretty easy.


8mm syringe has half units

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