Correction bolus

When do you do a correction bolus? 2 hours after eating, 3 hours, or when you pump gets to no insulin on board? Also I have been back and forth on bolusing for snacks. My endo said anything under 15 to not bolus for. Our day around here starts at 5 and I need to eat a little something before lunch. The same goes in the afternoon with dinner at 5:30. Thank you ahead of time.

I do a correction bolus whenever I'm over target. If it's 2 hours after eating and I'm high I correct, taking into account, of course, the IOB. I don't snack but if I did I would bolus for the carbs I was eating, the same as any meal. I don't really understand the idea of "don't bolus under 15 carbs". I can't eat carbs without covering them.

I correct for any reading where my pump recommends a correction, unless I think I'm going to go low for some reason. The pump should automatically subtract IOB, so "stacking" insulin should not be a problem if your insulin sensitivity factor is set correctly.

I bolus for all snacks. Never understood the "don't bolus for under X carbs" thing, unless you're low.

I'm pretty much with Zoe on this one, with a CGM wrinkle. If I am over target @ 2 hours (and especially if the CGM has me trending up @ the same time), I will do a correction. OTOH, if I am over target and the CGM has me trending down, I won't do the correction.

I always bolus for a snack with carbs involved, with similar CGM caveats. If I am trending down and below 80 mg/dl (and my meter reading closely matches the CGM), I might not bolus.

I usually correct at any point depending on IOB. I also bolus for all carbs unless I am eating glucose tabs to raise a low. One grape can raise my BG by up to 10 points, so I have to bolus for all carbs.

This. Especially when 15 grams of Carbs represents a whole meal sometimes.

I don't have a single set time to correct. I correct at 2 hours after breakfast but wait 4 hours after dinner unless I'm trending really high.

I won't bolus for a very small piece of chocolate (my equivalent of a single grape) or a handful of nuts but I will always bolus for a real snack - 6 carbs of yogurt for example. If you don't bolus for 14 carbs you're likely to see a 70 point rise in your blood sugar if your basal is set correctly. That's a lot.


I correct when I need correcting. Translated, that means whenever my BG is higher than it should be. If I'm high in the morning, I correct. If I'm higher than my normal pattern says I ought to be, I correct. It doesn't matter whether I've been fasting, have eaten, or whatever; if, based on IOB and food consumption, I am significantly off from what my calculations say I ought to be, I correct.

This is essentially what a working pancreas does -- it tries to keep BG close to normal no matter what's happening. My goal is to do the same, or as close to it as I can realistically get. My corrections are dictated by my meter, not by any schedule or clock.

I just want to point out that IOB is at best an approximation. I learned that the first time I went over 250 a couple of hours after a meal and my pump recommended testing for ketones and suggested a bolus of .05 units.

If I'm running high 2 hours after eating, I often reduce the IOB as calculated by my pump.


One way to do a correction while reducing the risk of a subsequent low is a super bolus. The idea is to "borrow" up to four hours of insulin from future basal insulin, and deliver it right away, as a bolus. This can also be used to reduce a post-meal BG spike.

For example, say your BG is 200, and if you wait to let IOB bring it back down, it'll be elevated for two hours. If you want to bring it down more quickly, you could give a super bolus of, say, 2 units, and then reduce your basal insulin over the following hours, e.g. if your basal rate were 0.5/hr, you could set a temp basal of zero for four hours (4 x 0.5 = 2). The nice thing about this is if after an hour or two you notice you've undercorrected, you can always turn your basal back on.

Super bolusing is tricky, because it can risk hypos, and the fact that our insulin takes about 1.5 hours to peak and hangs around for 4.5-6.5 hours means you have to be savvy in your application. But under some circumstances I find it incredibly helpful.

Anytime I check, and my pump calculates I should give one.

This can be as little as none in a 24 hour period, or many, depending on how stubborn my IR is being. If a really bad day, I'll just turn up the basal and keep an eye on the BG.

Niccolo - I like the super bolus correction technique you describe. That way, even with a large IOB within two hours after a meal, you can simply shift the timing of near term insulin delivery. This is the kind of thing where pumps really shine. With MDI, your basal commitment is already made.

I’ve probably read about this somewhere before but I now plan on using it. Thanks.

Here's John Walsh on the super bolus:

I'm a big fan. But it is playing with fire a bit. I've been playing around with both super bolusing and extending the time between my bolus and my food intake, and with the extra super bolus insulin on board, I have to be careful not to let that time extend too long, or I risk a low before things bounce back.

And agreed that pumps shine here. And I suspect in future we'll see these kinds of functions get integrated into pumps, too, though doing so in a way that doesn't confuse less thoughtful pump operators is a tricky challenge.

I don’t use the mealtime super bolus as I find the combination of immediate and extended boluses with an appropriate pre-bolus time usually matches my meals well enough. I’ll click through your link to refresh my memory.

Yeah, super bolus is sort of the opposite of an extended bolus.

Personally, I haven't found a use for the extended bolus function, I find our insulin duration of action already plenty long enough, really too long, for my meals.

But for that reason, I find the super bolus helpful for curbing that initial BG spike, allowing me to eat sooner after a bolus, or lowering a high more quickly.

I read the Walsh super bolus piece. I wonder if his technique works well with large carbohydrate meals. Eating large carb seems like a dangerous dance to me.

Variances in insulin absorption and meal absorption make a small percentage error into a multi-unit insulin error and presents significant risk for hypo- and hyper-glycemia.

Agreed, the law of large numbers means that at least for me, I avoid very high-carb meals with only rare exceptions. But for me, that's less the application for the super bolus. The super bolus is more about simulating super-duper fast acting insulin, in other words, it lets me pretend that my Novolog is really Novo-even-better-log. So I can better cover post-prandial peaks, more quickly reduce highs, eat a little sooner after a bolus, etc.

Same for me.