Delayed Insulin Absorption

Hi Everybody,

Since I started using my Dexcom G6 80 days ago I have learned so much about my Type 1 diabetes. One troubling thing I have noticed is that injecting fast-acting (Novolog) into my thighs results in very delayed absorption. However, the insulin doesn’t go dead! This morning at 12:40am my glucose was 185, I took a bolus of 4 units of Novolog to bring me back to my target of 100 but when I woke up at 4am my glucose was 166! I drank my morning coffee and took the required insulin to cover my creamer carbs and the additional to bring me back in line then I jumped on the elliptical and BOOM! My glucose cratered!!! As long as I can exercise or move around the insulin absorbs just fine but if I am inactive the insulin just stays pooled without absorbing. Has anybody else encountered this? How have you adapted?

For me, if I have more than basil insulin onboard and then add exercise, I go low.

So if it was me I would suspect the correction bolus done with your morning coffee and not the insulin at 12:40 as the cause of your low.


I try to walk to lunch on work days. About 30 min walk.
When I don’t walk, I need to take insulin about 30 min before I eat, but when I walk it’s more like 10.

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Yes, for basically my entire life. Caused an uncountable amount of seizures in my childhood (most often at night while asleep but sometimes even during the day). I just don’t absorb insulin reliably, one day insulin will work as expected and the next high BG’s that don’t come down for hours and when they do it’s after all of my IOB should be gone.

I’ve learned to avoid rage bolusing and just watch BG’s closely on my CGM. I avoid having a large amount of insulin on board before exercising if possible and if not possible then keep low treatments handy. I recently got a Tandem X2 pump with Control IQ and while I am pretty happy with it on the days where I am not absorbing insulin correctly then the automation will end up giving too many corrections when my BG doesn’t come down in the expected time frame and BOOM low BG that requires multiple low treatments.


Thank you Firenza!