How to take a correction bolus

When do you take a correction bolus? Must you wait 4 hours after your previous bolus or do you just do a correction bolus if your 2 hr pp is say 200?

i generally think 2 hours is safe, although i’m way less hypo-phobic than most people. some things that will cause me to hold off:

-my PP is not dramatically out of range (140-170 2hr pp)

-i had an unusually high dose of insulin or an unusual meal

-the meal did not have a lot of fat or protein

-i split a dose (i typically do this with big multicourse meals when i go out)

200 is always an insta-correct for me btw. if you’re worried about a hypo you can slightly under-correct and see what happens.

When I was on shots I would correct if I was above 10 (180 mg/dl) at two hours. I would only use 50% of my normal correction dose, though. I still went low sometimes, but at least it was something (and my numbers were too crazy on MDI to really tell what was doing what).

The only exception was before bed, when I would not correct unless I was above 12 (216 mg/dl), and then I would only do one unit, otherwise I’d risk a low overnight.

I am the same as ultravires on this, though I know some people hesitate to correct at the two hour point. The important thing is to know your ISF and keep track of the IOB. (God that sounds jargony…lol). For safety, you have to know how much insulin is still on board from your mealtime bolus. So figure what duration you consider insulin acts for you (most people do between 3 and 4 1/2 hours), divide the dose to see what is left, then add this to your planned correction to achieve your desired drop. I believe you said your correction factor is 1:80? So if you are at let’s say 220 and you took 1 unit of insulin at Noon and it is now 2PM.: Using my duration which is three hours: I would say that 1/3 unit is still onboard. At 1:80, if you took a one unit correction, 1 and 1/3 units would lower you 106 points to 114. I would go ahead and do this. With your ISF there are going to be times it isn’t safe for you to take a unit. I don’t know if you have a syringe that can measure 1/2 units but that would be useful for you.

My correction factor is more like 50 but I am not sure because I have never tested it without taking it in addition to a meal or snacktime bolus. I usually only use 2 units at mealtime. I took 2 units before lunch and ate more than I planned on eating ugh! and at 2 hours I was 232 now at 3.5 hours I am at 252. I have no clue how much insulin to take to correct or when to take it etc

Good points John, I was still climbing but now it has been 3.5 hours and I am still climbing.

For some reason I was under the impression that 2 hours after you eat would show your highest BG level so take my BG at 2 hours but I wait and take it again at 3 hours and if it the same or higher (above 150) I make the correction if it is going down I wait till bed time (usually 10:00-11:30pm) and take it again just to check.

Well if your correction factor is 50, and your sugar is 252. Then I would take 3 units to hopefully drop it back to 100. Especially if 4 hours has gone by. At the 2 hour mark i would cut that in half. But i am always more cautious with the two hour correction than a four hour. Like everybody’s been saying don’t forget about that insulin on board. And like JohnG said can you determine which way it is trending? That is very important as well. Don’t know if you have a CGM but you might try to get one. They are a amazing tool to help determine all that stuff! Remember some times when your high it takes more insulin than you would think to bring you back down.

I’m still doing research on how many units it takes to drop my BG X number of poins. What I have found so far is that with me it depends on the type of food I have eaten that caused my high BG. Do you find this also or am I missing something? I find this interesting.

Hi -

If you know why you need more insulin then I don’t think you have to wait more than two hours to correct the mistake. For example, a couple of times I simply forgot to bolus. I’d weigh the food, calculate the carbs write it down in may book and … failed to push the button. When I tested 2 hours post - feeling not so hot - I was 200+. I just took the calculated dose and tested more frequently that afternoon.

If you are nervous about going low, correct to 150 and follow your blood sugar closely.


I am very situational in my approach. If I think my carb count is off, I will do CBs in the 110-120 range on the CGM, if there’s > 5 point difference in the numbers, like 110-116-122, I will figure it is going up more and head it off at the pass. A more mild version, like120-121-122-123 I’ll wait a couple more rounds? If it’s a really big meal, I might wait a little bit and let it run higher but usually I don’t let it get very high before I fiddle around with it. Although sometimes I’ll compromise and walk the dog?