How long before a meal do you inject?

i have been reading about injecting insulin up to 30min before a meal. i am wondering how many of you out there do this? i usually inject just before i eat, but from what i have been reading it is advisable to inject 30min prior to allow for the insulin to start working as soon as you start to eat. i do have a problem with not feeling lows, so this is a little scary and i fear i may drop before the meal without noticing.
so do you inject right before, or 20-30mins before or right after eating? i know some that inject after a meal so they can decide how many carbs they have eaten afterwards.

30 minutes is a while to inject before eating and it is not something I would normally do. If I had a high BG (maybe 220+) and was planning a meal I may take my bolus (carb ratio and sensitivity) 30 minutes prior to a meal. I would be concerned of going hypo before the meal and before the meal hits my bloodstream just like you.

20 minutes before a meal seams more likely. If my BG was a little elevated (160+), I wanted to eat a lot of carbs, and the glycemic load of the meal is high. I think this may be a trial and error type of experiment that you have to conduct to see at what point you go hypo and at what point you PP 1 hour and 2 hour tests stay the lowest.

I like to bolus maybe 10-12 minutes before any meal of 45ish carbs or more (if my BG can handle it).

30 minutes before a meal sounds like the old humulin R or Regular talk, but I guess it all depends on how fast your insulin starts acting on the carbs.

My son is on a pump and his doctor and dietician want him to bolus 10 minutes before a meal if his bs is in range and 20 - 30 minutes before the meal if his bs is high.

I try to bolus 40 minutes before breakfast, ideally 30 minutes before other meals or carby snacks if my blood sugar is 80 or above. This length between bolusing and eating seems to help calm, although not necessarily prevent, the post meal spike. If I’m in the 70s I usually eat 15 minutes after the bolus, and if I’m lower than 70, I eat a glucose tablet or drink some milk first, then retest and bolus. I have a pump.

With NovoLog around 0 to 5 minutes before eating. With Acctrapid it was around 15 to 20 minutes.

How high is your BG at the 1 and 2 hour mark after eating?

It really depends how long insulin takes to kick in for you. If you don’t know how quickly it kicks in, you can find out by injecting and then testing. That’s how I found out that Novorapid/Novolog takes TWO HOURS to kick in for me. So when I was on it (I call it Novoslow), I could inject and see absolutely no difference in BG for two hours.

I now use Apidra, and that kicks in in 15 minutes.

Everyone’s body is different - you have to work out what is best for you.

I inject right after eating. too many times in the past that I injected and did not eat everything. Bad news for me.

I inject (Apidra) usually 15 minutes before eating, then if I don’t eat for 30 minutes I will still be fine. For me, a correction from like 180 can take over an hour before I notice a change. I guess I figure if I can eat a piece of candy and raise my BG 30 points in 15 minutes, and it takes an hour for my corrections to kick-in, I should probably be injecting at least 15-30 minutes before eating.


Well, the time depends on the insulin!

Years back, when I was on Actrapid, I had to wait 30 minutes. With NovoRapid, it’s said to be 10-15 minutes.

How long I actually wait depends on the situation and my bg. I try to go with the 10 min. But it varies.

As said, it really depends on the insulin.

Today, I could never wait 30 minutes before I start eating, if my bg wasn’t very high, and in those cases I may not want to eat at all. If I’m in range, I wouldn’t risk waiting so long, especially not during the summer. I recently corrected a 300 (oh, the food abroad…!) and an hour later, I found myself at 30. Exactly that would happen if I took insulin for a meal and waited too long. NovoRapid kicks in too fast, and sometimes even faster when it’s hot outside.

I inject (pump) humalog within 10 minutes of starting a meal. But I take some time eating so that apple for dessert is eaten maybe 30 minutes or 40 minutes after injection. I eat high fat/high fiber and prebolusing tends to make me go low early and high in hour four. It really is a matter of trial and error.


thanks all of you for your input. i guess i should have mentioned that i use a pump and am using Humalog insulin. basically everything you all mentioned had crossed my mind. i think, that since for the most part, my BG’s are within range 2hrs post meal, i will just continue doing what i am doing. of course, there are the occassions when it is high but that could be becasue of eating pasta or my favourite, mashed potatoes!!! do any of you pumpers ever do a a combo bolus? and if so how do you figure it out. i am using the Animas Ping.

I think injecting before eating could be suicidal, especially for me when the Gastroparesis is in a bad mood and the food doesn’t stay down like it should, and that’s not uncommon these days…

Could be anywhere from a couple minutes after eating, to over a half hour, or not at all depending on how I feel, none of this is easy at all :shifty

I use the combo bolus (dual wave for MM) with some meals. In general I will use them when I am eating a high fat meal (pizza) or high protein (steak). Or I will try a dual wave when I have eaten the meal before and see my BG start to slowly wander up 3 or more hours after the meal (eating out). I suggest you look at some of the postings in TAG (Total Available Glucose - TAG) Group. That group will go into much more detail than I will and a bit of it is trial and error to figure out how you specifically digest things.

The basic concept is that about 40-60% of protein you eat can be converted into carbs and about 10% of fat can be. This conversion takes longer and therefore can raise your BG later than expected and slow the digestion of the carbs you eat. For me (through trial and error) I have found that taking 65-70% of the bolus (not including correction) up front and taking the wave for the remaining 30-35% of about 0.6 to 0.8 units per half hour (or 1.5 units per hour).

Things to be aware of: You probably have the protein and fat somewhat factored into your meals I:C ratio. Therefore if you are going to count all your carbs, protein, and fat you may overbolus (bolus what makes sense to you). From the bit I have read, diabetic's digestion varies a bit and my numbers may NOT be useful for you (but may be a starting point). It stinks when you are expecting a meal to digest slowly and dual wave bolus for it, then the meal hits your blood stream fast and all at once. You will get a bunch of Insulin on board with a rising BG that you can do little to correct. If you are eating a meal that you know (from experience) will cause your BG to rise at 3+ hours, they why not give it a try?

I used to bolus about 20 minutes before eating and for me with Apidra that worked fine. My only variations on that were if I were high I’d do a correction and wait longer and if I were low (in the 50s or 60s) I’d bolus and eat right away, unless the low was below that when I’d take a couple glucose tabs and wait for my blood sugar to come up.

I’m now on Symlin so I bolus one hour after eating, but that’s a whole different thing.

I’m like a few others where I used to give my fast acting insulin before I ate - but then sometimes I wouldn’t eat as quickly as I thought, or I couldn’t eat all that I had on my plate - so stopped doing that. Depending on how my blood sugar (BG) is at the time - I’ll sometimes give a correction injection with abit more to cover the food I’m eating - but not all of it - and then test abit later to see how my BG is doing and then either give abit more insulin to keep me at a level that I’m happy with. I use the same method as well with my insulin pump, except I set it up in the programming of my pump with an extended bolus. It all depends as well as to how much protein/fat you have in your meal - as that slows down the absorption of food into your blood sugar. It took me about 30 years to figure this one out and I’ve been a diabetic most of my life :slight_smile:

I use Apidra in an Omnipod. If I’m home I bolus 30 min b4 eating. At a restaurant I usually wait a little bit just incase the meal is late in being served.

20 min. My mg/dl starts down at 25 min. I’m on humalog and low carb. If I have any question at all that i might not have given enough, I test at one hour after eating. If there’s any spike, I haven’t given enough.

Now that I read your answer I must say that I am adjusting my injection pattern too - it is not that static. High fat and carbs => splitted injection: 60% after eating, 40% later. Low BG before eating => dosage reduction and injection after eating. Only with a normal and stable BG I will inject just before I start to eat.

now that i’m on the pump i bolus right before i eat if i’m in range and maybe 10 minutes before if i’m higher. before the pump i would wait to inject after i ate because if i ate more than i predicted i didn’t want to give myself a second shot…no wonder i had spiking issues…go pump!!

Using Apidra I inject just before I start eating.
In the case of pizza and other foods with a lot of cheese (can’t think of any others at this time) I inject just after i finish eating.

  • I’m relatively thin