The Power of PreBolusing w Novolog (Flatliners: Look Away, Please....)

So I have appreciated @Nickyghaleb’s openness about having been essentially afraid of insulin for a long time (I apologize if I’m misquoting you, Nicky). I am, too. I didn’t used to be. But as I’ve mentioned probably a lot of times, I got much more skittish about prebolusing since having kids. The reason for this is that it is easy to lose track of time, I’m up and moving so much that I assume any insulin I take will get working much faster than it did pre-kids, I’m concerned about it dropping me before I’m ready, etc etc etc.

So I made myself test it, leave it alone, and see the rational difference for myself this weekend…but only after Saturday was a total disaster from NOT prebolusing enough.

The first graph is: 7 unit injection, 34 grams of carbs, 10 minute prebolus, eventually followed by a two unit correction at 3PM bc I wanted to give the insulin the full chance to work bc I needed to SEE it for myself. The reason I didn’t prebolus longer was that I’d been doing so many chores, I thought it would be dangerous to prebolus too much. Clearly, I was wrong.

The second graph is: 6 unit injection, same 34 grams of carbs (like, actually the same lunch), 30 minute prebolus. This graph ends after 3 hours of insulin action, so I’m still dropping and will get to eat more at the end of this likely.

My point in sharing this is in case anyone else reading this, lurkers or otherwise, also struggle with prebolusing long enough. For me, on the weekends when I am doing chores and parenting and may or may not have another adult in the house, the near panic is pretty real once I get 20 minutes from my injection and haven’t eaten yet. I did this exercise to show myself why it is actually safer to prebolus longer (like 30 minutes vs 10)…bc then I am not riding the rollercoaster, taking correction doses, and getting drops later from the accumulated effects of misdosing.


@T1Allison, super valuable post!

We also prebolus regularly. A couple of tricks we use to help with the same problem (they don’t solve it all):

  • We try to keep 10-12 rations of mid-carb meals in the fridge as leftovers at all times (for instance dishes with chick peas or beans, or sometimes potatoes) so we can improvise a meal with any number of carbs quickly

  • We also keep lots of fruits with known carb values, for the same reason (typically mid-sized clems, oranges, pears, pre-cut honeydew, sometimes bananas)

  • We ask our son to set up an alarm 5 minutes before his insulin is due (for us, that means 40 minutes after bolus). But it can be quite irregular :frowning:


I like your strategies. I always have my lunch ready at the same time I inject just in case my insulin gets legs early…but that also means colder meals. Your plan is better.

If I ever write a memoir, it’ll be called “Waiting to Eat” :joy::joy:


I had such a sudden laugh when I read your line :slight_smile: It is not funny and yet it really is!


Cool. Are these with or without your +5% temp basal one hour before and after (which I’m in love with, by the way)?


Without. I was doing straight bolusing.

I also remember now that I was super frustrated being so high, so the drop you see in the first picture is the result of a 20 minute nuclear shower. Without that, I probably would have just stayed flat and high.

Glad the +5% works for you!! I do it on work days but I haven’t tested it on weekends yet…the activity difference gives me pause although maybe it shouldn’t.


Terrified. I was terrified.



First, the title made me laugh so hard.

Second, thank goodness we are not the only one with messy graphs.

We really struggle with the pre-bolusing thing. Probably because we eat out a lot, and it’s really unpredictable, but even at home sometimes. And there are so many confounding factors. For instance, yesterday, we wound up going out for Indian food around 9 PM. After a pretty physically active day of hiking, following a long stretch of days with zero exercise. It was a complete disaster! EH bolused an upfront bolus and then an extended bolus, crashed down to 55 mid-meal, took a correction with a mango lassi as dessert basically. Walked back to the hotel one block, he was at 42. He knew this was setting him up for disaster, having had a super carby meal and then tossed fast acting dessert sugar on top - but what to do? Waiting for the food to kick in hadn’t worked - he kept dropping - hence the lassi. Waited it out and normalized but then the late meal digested overnight sending him up to 250 in the middle of the night which he woke up to correct half a dozen times. Then he plummeted at 8am.

I’m not trying to talk anyone out of prebolusing. I think that might be the key to success for us even (as would eating dinner earlier…or exercising regularly…or…or…). We’ve also had the prebolus issue where we arrive and the (predictable, previously eaten at and understood) restaurant is closed, and then there’s traffic unexpectedly, etc.

I guess I’m presently frustrated. I also recognize that we’ve chosen a lifestyle that doesn’t really permit waiting to eat or even eating at home all the time. Which I suppose is the trade off - better management is out the window. :slightly_smiling_face:

Do you set an alarm to remind yourself to prebolus? Or do you do it as your cooking? I love that it’s working better for you! And that you’re not afraid. :smile:


I do use alarms on my phone to let me know when 30 minutes (or whatever timing seems appropriate for the conditions) is up. This helps guard against distractions at work and at home.

I am most capable of following “best practices” when I’m already in range and when the day has behaved close to as expected. I still have great difficulty in adjusting to foreign conditions “correctly”. And when I don’t know what to expect from my blood sugar for a new situation, I tend to panic correct too soon.

I definitely am not a flat liner. I would love to be. But I am not. BUT, my control and my consistency is the best it’s ever been, which I feel good about. I just hate getting stuck in the bg ditch and am trying to get myself closer to that lower end of the spectrum without scaring the heck out of myself.


That’s excellent news!

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I would like to join in, i am not a flat liner, but of coarse am trying! Prebolosing for me has been a problem, my boluses normally don’t start having an effect for 45 minutes plus and food longer, (my stomach is slow) if I prebolus for the amount of carbs in a meal (not factoring in correction) I will go low then high and fight to get down, then low again. What I have started doing is calculate my dose and if any correction is needed do a dual wave doseing correction up front and 50% for 30 minutes and dividing the remainder 50% into a temp basal increase for two hours (if that makes since) and watch reading for rise, when I get to around 150 I’ll bolus 2 more. If it continues to rise I’ll use temp. basals again and watch. Very rarely do I go over 200. Once I start to level out or turn down I cancel temp basal. Have gotten to point I normally land pretty soft.


I just wanted to add, I cannot eat Indian food at all. I end up just like EH! :frowning:

I’m also not a flatliner but like all of us, would love to be, and I know we all try our best!!


I like what you said here. I can completely relate to this…although it would be awesome if that was bc I was out eating dinner at 9PM and rock climbing…mine’s for different reasons but this is totally relatable.

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Yesterday was not the first time I forgot I’d bolused for a snack…thankfully something always manages to happen that reminds me before my BG gets too low, but I really should set alarms like @Michel. :slight_smile:

Pre-bolusing with kids is so hard. It’s why I use Afrezza for most lunches and dinners. I can swing a pre-bolus for breakfast because I have to wait an hour before eating after I take my thyroid meds anyway…

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It went wrong, but it tells you what to try next time you have this food. Smaller upfront, longer extended bolus, and look early to see if there are hints of too much insulin in which case cancel the extended bolus and maybe put on a smaller or longer one. I tend to get a spike and crash and then a very late big rise with Thai red curry, and am down to 25% up front and 8 hours extended but I only eat that dish about once a year, so there’s some kind of race to see whether I figure out how to do it during my lifetime.


Honestly, I just don’t see consistency when eating high carb/protein/fat meals. Even when I think I have it figured out, it’s usually coincidence or luck and there are too many variables that affect the speed of digestion and insulin absorption to bolus perfectly. I just watch my CGM/libre if I eat a difficult meal and try to adjust with insulin or glucose tablets for highs or lows. I think this is where loop/AP systems will have a real advantage.


I think this is exacerbated when eating out, because the amount of fat is so variable. I was at a party and there were two higher end restaurant cooks and they talked about mashed potatoes and in one of their places the mashed potatoes were 50% butter by weight and the other 35% butter by weight. They would look the same, but the amount of fat would be hugely different. And this applies to every part of the meal. So even day to day, the prep cook may use a different amount of fat in the meal. This makes it pretty difficult to guess what you are going to get. After listening to these two gentlemen, I also never eat mashed potatoes when eating out. My god, who would have thought 50% butter.


But that’s what makes potatoes taste good! :laughing: I say this as someone who can’t eat dairy, so I may be biased in my longing for “real” butter… :wink:


This is good advice. We’ve twice cancelled an extended bolus this week because “tacos” (or whatever) weren’t as expected (for instance one night I managed to order lower carb Chinese delivery. I don’t know how. It was amazing.)

Also, 8 hours extended is amazing!!! Thanks for sharing!!

Well, heck. No wonder they taste so amazing.