Drops between hour 4-6 after bolus Novolog duration, 4, 5, 6 hrs?

I tend to drop between hours of 4-6 after a bolus. If Novolog’s duration is 6 hours as I have seen on many places how much should one expect to drop between hours 4-6 assuming basals were correct?

Not nearly as much. I think you’re going lower at the peak, and the edge tapers off.

That being said, the tail of Novolog can be greater than six or eight hours. I’ve experienced wicked tails at least eleven hours after inection, especially overnight. Also, the action of Novolog seems to be particularly sensitive to exercise.

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If I eat higher carb meal, with little fat or proteins, then i experience this. Either reduce dose, with a bit higher peak before it goes down, or consider food changes.

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Wow! This would explain many things. EH was just saying he feels like the tail is way longer than he has the pump programmed for.

For me, the duration of insulin action becomes extended only in the case of a large bolus. Especially over 20u.

And of course, the nutrient content can affect the onset and duration.
Meals that have substantially more protein/fat can have a big effect on the duration curve of “rapid” insulin.
Personally, I use this chart as a guideline/reference, which, for the most part, is fairly consistent in my case.


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So it seems for most 4 hours is it?

I ballpark my duration at 3.5-4 hours usually. If I’m sedentary and have to take extra insulin to make up for the lack of activity, I’ll see its duration last longer…to around 5 hours. If I’m really active, it tends to be 3 hours or less. But even with the longer tail during sedentary times, it shouldn’t cause major drops…just a downward trend. If I’m seeing a significant drop more than 4 hours from a bolus, then I’d examine my basal or other factors that might lead to a drop.