Insulin Stacking Question - Educator confusing the bejeezus out of me

So here’s the situation:

Dinner Last night (BG 110) is 43 carbs at 8PM. We MDI with Dexcom G6 (though these levels are verified with meter). I dose Liam 1.5 (1 per 25) levels are solid between 100-150 (150 for a tiny bit, but mainly 100-120) until 10:15 when they start going up.

By 11:00 PM he is 180 (his dosage is 1 per 100 for over 150). I give him a 1/2 unit at 11:00.

By 11:45 he is 220. Since if I had checked him at 11:45 I would have given him a full unit, I give him another 1/2 unit (1/2 + 1/2 = 1 unit).

He drops to 180 by 1AM and SLLLOOWWWLY drops to below 150 by 3:30.

By morning he is back in the 100 range. Because we have not had a resistant high before (Liam is 5 and was diagnosed a month ago) I called the Endo to see if there was anything i should have done differently.

She got REALLY uptight that I had stacked his doses – even though the total dose I gave him was equal to what I would have given him if I had checked him at 11:45 and saw him at 220. She said I should wait the full 3 hours to see what the insulin should do. However, since i didn’t dose him more than 1 per 100 I don’t get it.

Is diabetes a mystical unicorn and she is right that I could have caused a drop into lows that was dangerous, or is math not her strong suit? I don’t want to take risks with my son, but I don’t think based on the standard doses we use that I did. If he hadn’t broken 200 I would have waited the 3 hours.

I’m super confused.



She’s just being cautious since very few patients are aware and/or capable enough to be that careful with the math and dosing. Endos, especially pediatric ones, are going to be very cautious to avoid hypos generally, and may have conservative blanket rules to that extent (like always avoiding stacking insulin). If you really understand what you’re doing and aim for tight control, you are going to tend to go outside their general comfort zones a lot of the time.


Very mystical sometimes. That’s why we experience these persistent high BGs despite correction boluses or sudden drops when we haven’t taken insulin for hours.

It is kind of a dogma among medical professionals that stacking is bad. They are not entirely wrong about that, because stacking indeed can cause quickly dropping BG levels resulting in a hypo. So you do have to be cautious. However, CDEs and endos sometimes stick to this dogma even when it doesn’t make sense to do so. In some situations it is perfectly clear that the correction bolus will not be enough to get BG levels back to normal. Then I personally see no reason to wait the full three hours. With a child you might be more cautious though.


Who would want to wait a full 3 or 4 hours for a correction to take you down, if it even does. Depends how high you are. I always give myself more/sometimes twice the correction. Comes down quicker and BONUS you get to eat something to keep it from going too low.


That’s not something you want to do with small children.


You’re right about that.

A month in I definitely won’t say I really know what I am doing— but I feel like The logic is sound. I guess I wonder in my situation if people would have done the same thing.

We would have done the same thing, maybe even more aggressive, but that is because we have lots of experience doing it. The fact that you are only a month in and are already grasping the basics and working on the advanced stuff bodes very well for your son. You will certainly have better control than most. As others have said, be conservative, but if the situation demands stacking, stack. We don’t hold to any rules hard and fast. We just use the CGM as a guide and figure out what works best through testing. I think the no stacking thing would be more appropriate if you were having issues grasping the basics or if you were only using strips instead of sensors. You are doing great! Please also bear in mind that your son is probably producing his own insulin, so there is some reason to be conservative.


Also remember you have time to figure this out. Nothing in the short term is going to have long term effects. Please take your time and be sure you understand the basics and how Liams body reacts to insulin dosing and carb intake. Your expertise will come with time but right now you are a novice and should focus on the basics and learning as much as you can.

I’ve been at this 38 years and it still puzzles me sometimes.


Firstly @Jess you are doing really great - MDI, Testing, getting the dexcom G6 up and running and understanding all of the terminology, ratios, etc etc. Your son is very lucky.

My daughter is 4yo and uses humalog through omnipod pump (only) - this is based only on my observations with her. You may be also using Lantus? I have glucose and glucagon ready to go if I need them - I think this is necessary if you are going to give insulin corrections to a child after 10pm.
I am also assuming that the carbs were complex carbs rather than sugary carbs. There is also a difference here - for example I will dose my daughter 1.7u for whole grain rice and 2.5u for brown pasta.

If your son does not return to 110 or 120 within 2 hours after dinner then the carb ratio can probably be adjusted to give more insulin. I notice that you said 1/25 which leaves you short insulin for 43g carbs but I guess you rounded down as humapen can only give 1.5u or 2u?

Usually for Audrey I correct at over 140 which you did. 3 hours had passed 180-50=130 so this is fine.
The second half unit is a little tight timewise as it would drop 130-50=80 BUT as he was reading 220 I would probably have given this 0.5 after a test strip confirmation.

Another consideration at 11pm is the average duration of action of rapid acting insulin e.g. humalog is 5-6 hours. I am always very conscious that giving Audrey 1unit at 11pm may cause a <70 low at 4am. IoB is a term commonly used - insulin on board.

I agree with @cardamom

You are probably well ahead of where most people are after 30 days. I think you would benefit from reading the book "Pumping Insulin by John Walsh - make sure you get the 2017 6th edition.

There are a few benefits to the pump which you would probably notice after this
the pump can give dose’s like 0.65 and 0.85.
You would not have to inject twice while your son was sleeping - you can dose from phone



Did meal contain fat/protein ? Is 8 pm typical meal time ?
Was the dexcom flat ? Meal dosing can be influenced by many other factors than just carbs. You can learn more from the Sugar Surfing book by Stephen Ponder. Also a website with much of same info. He is T1D endo, and treats T1D children.


I have so many comments about this.

To start, I’ll say the dosing decisions you made look entirely reasonable to me.

The hazard of course, is a severe hypo, not the act of stacking insulin. For those of us with trustworthy CGM, and who are able and willing to respond to CGM alerts and unfolding trends in the CGM graph, and who have the means to compensate for too much insulin (i.e., glucose tabs at hand) — for us insulin stacking can be a very useful tool. I take some insulin; if the CGM graph looks like it wasn’t enough I take some more, but I’m always prepared to recover promptly when I take too much.

I think that the medical professionals recommend against stacking insulin doses because they are trying to guard against severe hypos, and too much insulin is the usual cause of severe hypos. Common insulin takes quite a while to get into full action, and continues to act for an extended time. So it is easy to overdose while stacking insulin to try to speed up a correction. I do that routinely, and routinely have to rescue myself with fast carbs when my multiple aggressive corrections take effect. I believe that I can do this safely, and that it helps me get back to a good BG level quickly, but I can’t imagine that a prudent medical professional would suggest that I stack some rage boluses when I’m experiencing an excessively or stubbornly high BG.

You explained that you properly calculated the correct insulin dose, so it was safe. That’s actually a weakness in your story, because experience shows that a carefully calculated insulin dose sometimes isn’t enough, and sometimes is significantly too much. The body isn’t a machine, and doesn’t always respond as predicted. In particular, there’s a potential hazard in taking insulin before going to sleep, and the educator may not fully trust that you will detect and fix a late-developing hypo overnight.

The key point is this: it is your degree of attentiveness and ability to respond to the actual BG trend that distinguishes whether you cause danger or not.


As others have said, you’re on a good path already - curiosity, learning, asking questions and advocating for Liam. Keep up the good work.

And welcome to the FUD forum! So many here with experience and encouragement to share.



This is a key point. Whether you should stack or not, especially with a child, probably depends on your ability to monitor carefully over the next many hours. If you feel confident about your ability to do so and intervene if hypo, then that’s less of a concern. If you feel less than fully confident about it, maybe better to take a more cautious approach. Also if you’d prefer to prioritize not needing to possibly wake up to treat a low, it might be reasonable to choose to be more cautious and protect sleeping time at any given point—there are lots of trade-offs we all need to consider in our decisions, because we are playing a very long game, so it is going to vary much of the time, and we don’t always need to stick to the same strategies.


Hi @Jess,
Somewhat related - do you guys have a glucagon kit for emergencies?


From my point of view, I’m not even sure I would call what you did stacking? The first dose was based on his BG level, which then kept going up. The second dose was based on his new level and only included the difference. Albeit rounding up versus down, probably because you have to give in half units? To me that is not stacking except for the rounding up portion.

The rounding up could be the potential problem I see, which is why he ended up closer to 100 upon waking versus 150. Pumps are not for everyone, but the benefit of a pump is you can give doses as little as .05 of a unit. Luckily you have a Dexcom, dosing kids can be so scary.


We have a glucagon kit ( actually 2) and we also have baqsimi (because they had a coupon for a free prescription.)


That’s where I was. My math was- 180-50 = 130 but then additionally once he hit 220 assumed only correcting for the differential, so 220-180= 40 then an additional 10 off the 130 to 120. (Realizing that a direct relationship like that is never exact). (Again all CGM numbers verified by finger pokes Before dosing). I guess the question I have is - how is that any different than waiting 20 minutes for his BG to reach 201 and then dosing him 1 unit as long as the second dose restarts the “3 hour check” clock. (I am not being snarky- I really don’t get the chemistry/biology that makes one ok and one not- does a second site theoretically make the doses absorb into your body faster because of increased surface area allowing for more opportunity to drop quickly?)

That night here is how we were prepped for lows (because I figure folks are curious):
We have Dexcom alarms set at 80 (and Sugarmate calls me). Also since I hadn’t done a dose like this before I stayed up an extra hour + To watch the levels fall- I wanted both to see the speed at which they fell and to make sure they fell below 180 before I went to bed then told my husband who was up working late.


I will get this- thanks!

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That totally makes sense- thanks!