Timing insulin

HI, I've been meaning to post a discussion about this for awhile... when I was first put on insulin (pork/beef) in 1984 the doctor told be to wait 20 minutes minimum up to an 1 hour before eating (If I recall correctly). Mid to late 1980's I began using Humulin R (short acting), the doctor still told me to wait at least 20 minutes up to 1 hr before I began to eat food. I would usually wait 30 minutes.

Fast forward to 2002, with the invention of "rapid acting insulin" my doctors began telling me I could eat right away, "this insulin (Novolog) begins immediately!" So for years I would eat and dial up my insulin at the same time. Why would I wait? this is silly, so 1984!

I do a lot of good for my diabetes, I TAG most of my meals, I use a pump where I can deliver a Dual Wave Bolus, I wear a CgM that has a blood sugar trend arrow on it, I eat a semi-low carb diet and even exercise a little each day. All of this is thrown out the window if I do not time my insulin and food properly up front, honestly. I notice (for me) Novolog does not start working "right now".. it just doesn't, no matter how much they want to tell me this. My blood sugars are SO much better when I wait 20-30 minutes.

Do you time your insulin? Did your doctor tell you that you could bolus right as you ate? ... no wait time? Do you have decent sugars when you eat and bolus at the same time?... or do you find if you wait a few minutes your sugars are much more spot on? What did your doctor tell you on this topic? Please include what insulin you are injecting...


I will wait unless my BG is below say 85-ish, depending on other variables like drinks, IOB, exercise plans, etc.? I enjoy food quite a bit more if I feel the buzz from the insulin I think?

I would wait longer w/ R or do IV R shots for CB to make them work faster back in the days. I think that they work quite a bit more quickly than "super fast acting" 'logs with, of course, considerable risk.

I wait 15 mins after I have taken my insulin before I eat. If my sugar levels are low, I just eat. But then it goes sky high after being low. I discovered that if I eat asap when I am high, I stay high.

Even “rapid acting” insulin analogues are super slow compared to the naturally-produced stuff. Naturally-produced insulin starts to work instantly and has done its thing and is gone after a matter of minutes. Rapid acting insulin takes minutes just to begin working and is not really working that hard until an hour or two later, and is not done its thing and gone until four or more hours after injection. That is very, very slow.

That's a very useful chart.

The other 'stat' I'd be curious about would be the 'probability'? When I had my pump installed, the endo and/ or MiniMedSalesNurse explained that N had only a 53% chance of peaking when it was supposed to? This immediately explained many of the odd #s I'd dealt with for oh, say 20 years. They also said that the newer insulins were 'more accurate than R/N but not as accurate as a pump' but, since that was about the last conversation I had about shots, they didn't elaborate and I haven't ever looked it up. Some of it might also relate to the size of the shot since, as noted by Dr. Bernstein, shots > 7U are absorbed less smoothly, leading to fluctuations down the road?

I recently started Apidra and noticed that it seems to be out of my system very fast. I didn't believe it could be gone in 2-2.5 hours as it seemed to be, but according to this chart it can. It's interesting that this chart shows it starting to work quite a bit slower than Humalog, which I was previously using. I do notice when I correct highs it takes forever to kick in and then seems to kick in all at once. My after-meal numbers seem to be lower on Apidra, even when I test at one hour, but I wish I had a CGM so I could see how high I really spike. I trialled a CGM through my hospital clinic about two years ago and was shocked to see that even for foods I counted perfectly I could spike to 15 mmol/L and then be 6 mmol/L at two hours, never knowing I had spiked that high at all!

I do not pre-bolus ahead of eating but probably should. When I was diagnosed I was given Toronto (regular) and, like you, told to take my insulin at least 30 minutes ahead of eating (this on two shots per day, though, so no carbohydrate counting). I started Humalog in 1998 and was also told I could take it at the time of eating (still with NPH, two shots a day, no carbohydrate counting). Then I started Lantus in 2005 and learned carbohydrate counting and continued to bolus at the time I ate. Then I started the pump in 2007 and was told I could "eat whatever I wanted" from now on ... sheesh! Now with CGMs people can see how much they are actually spiking after eating and are starting to pre-bolus once again.

I usually eat within 5 minutes of taking a bolus but I eat a high fat, high fiber diet so that the insulin has time to catch up. If I pre-bolus for more than a few minutes, I have a tendency to go low early and then drift high during hours 3 and 4.


PS - If I waited till my BG was down to 85 before starting my meals, I might never eat :-)

I pump humalog.


I am an Apidra user and I truly don't get , that the duration is between 1-2 1/2 hours ( in the form shown) ...my sense is more like 2 1/2 -3 hours ...but I am not a scientist . My TDD of the last 30 days is 19.80 u ; am not a low carber , in other words I deliver small doses at one time .I think forms like this are guide lines ...and we are all different .

Time of bolus depends for me much on what my BG is at the time , so sometimes I wait 13 1/2 min ( ha, ha ) ...this morning( 4.1x 18 ) ) I drank my breakfast milk before I bolussed for breakfast minus the milk carbs ...it seemed to have worked .I use dual wave 99 percent of the time..again it depends what the BG is and what the meal consists off ( fried spuds , pasta deliver over 60 min . , rest 30 min ...if higher than 8 ( x18 ) I have tried to deliver " normal bolus " .And the exercise equation needs not to be forgotten .

PS I just wonder, when I have to go into the HOME , if the staff would know , what I am talking about :)

PSS I tried to post this just below the form ...and it did NOT work , oh well .

I have a weird timing routine because of gastroparesis, but here goes in case it's of interest to anyone. If I could ever figure out timing with this burden, I'd be one happy diabetic.

Breakfast--Apidra about 5 minutes before eating (dawn phenomenon).

Lunch--Apidra when I finish lunch

Dinner (the bad time)-- Apidra 45-60 minutes after eating, depending on the meal. Regular 3.5-4 hours after eating. Strange, huh? Sometimes I take Regular 30 minutes after eating & then Apidra later. Still figuring out which works better.

My doc told me to take Apidra 15 minutes before eating. Regular 45 minutes before. This doesn't work with delayed stomach emptying.

I wait longer to bolus if I'm low before meals.

You make me laugh :)

Actually self taught on the Apidra , after reading about it on TuD !!...and more reading .

Apidra became only available in Canada earlier this year ; I mentioned it to my Team at the Diabetes Center in August ; received samples , did not discuss " advice " and I felt confident enough to proceed . The Locum Dr. prescribed when I asked after she looked it up on the computer ( new product for her ) .

And I am happy to read Jennifer is taking the Apidra route !

Is apidra much more expensive than novo or humalog ?

Anthony ,in BC at my Safeway Pharmacy : 3x 10 ml Apidra $ 77.73 ,( BC Pharmacare paid $ 57.10 rest was paid by my PBC ) ...

3x 10 ml NovoRapid $ 90.36 , ( BC Pharmacare paid $ 58.90 , rest was paid by PBC ) ...these dollar figures may change on Jan 1 , 2011 , since we have to pay the Pharmacare deductible .

Apidra is cheaper :)


In 1984 I was told 20-30 min before meal for R beef/pork. Same thing when I switched to Humulin R. When I switched to Humalog they told me to take it anywhere from 15 min before to when the meal began.

I find it depends on what I eat. I use the times listed in Think Like a Pancreas:

  • 1 hour - 30% gone (70% IOB)
  • 1 1/2 hours - 50% gone (50% IOB)
  • 2 hours - 70% gone (30% IOB)
  • 3 hours - 90% gone (10% IOB)

I have found these times to be accurate for me. If my bg is on the lower side, I eat any carbs first. If it is higher, say 120 or so, I eat my veggies and protein first. That seems to work pretty well for me. I don't eat "low carb", but restrict any meal to 45 carbs max. This keeps my bg from rising more than 60 points at any point after any meal. I know some people will think that is horrible, but it is much better than I used to be. Also, I don't inject much insulin at once(Sometimes large doeses or insulin can throw off absorption times). My meal boluses are only 2 to 3 units, and my levemir is a total of 10-12 units per day.

Interesting like the Chinese curse--may you live in interesting times.

It still doesn't always work well even with my wacky timing. My gastroparesis was diagnosed because following endo's instructions resulted in lows after eating. Hey, why I am at 30 two hours after meals!

Thanks for the great chart.

That's because natural insulin is secreted directly into the portal vein, and goes immediately to the liver to stop its glucose output. What the liver doesn't use then goes to the tissues.And the pancreas keeps secreting for as long as necessary.

Injected insulin is backward from that -- it goes to the tissues first, and only later hits the liver. So the liver is producing glucose, even as the glucose from the meal hits your bloodstream. Result: high peak. Injecting a little early gives the insulin a chance to get to the liver and stop it from producing glucose.

Well, I had a lousy experience in a nursing home/convalescent center, but I hope you will have better than that, if you need to go!

For me it’s actually cheaper. I paid about $22 per five-pack of pen cartridges for Humalog, and only $14 for Apidra. I’m pretty sure the province covers the same (70%) of both insulins.

Do you find it takes forever to bring highs down? As long as I am in a good range it’s fine. But when I’m high, I stay high for a long time! For example, about an hour and a half ago I tested at 16.5 (dunno why as it was after exercise, but oh well), and I corrected, and now I just tested and am still at 16.0. I have heard of people needing to bolus more insulin when their blood sugar is very high as opposed to only slightly high, and I have never found this to be true but maybe with Apidra it is. Or maybe it just takes forever to kick in, as I will now correct this reading and probably crash low later on, but I hate just leaving it as I then may stay high. ARGH.


Could you give me the source of your chart? Thanks.