New Lantus User Lots of Highs!

Hi All

I am a brand sparkly new user of Lantus. I’ve been a type 1 diabetic and have always used Humalog for meals and a slow release for night but my dr told me I need a base insulin for the day. Since starting I don’t get it all. I have to inject double the amount of fast acting - thought it would be the opposite ? So now im injecting 16 at night and about 6 with every meal.This morning i had a yoghurt and injected 4 and when i tested myself an hr later my sugar was 20 ?!!! After lunch i had a sandwich and injected 5 and same thing sugar was 22 ??

Any advice greatly appreciated feel like just going back to my old routine .

Tnx !

Hi Char. I'm not sure I understand what you've written. Anyway, the usual method of taking insulin is a long-acting, such as Lantus; and also a fast acting, such as Humalog, for meals, snacks, corrections. A split dose of basal/Lantus, would be a morning injection and a nightly injection of it.

Okay so I am taking one daily injection of Lantus at 10pm of 16 units and then I take fast acting Humalog with every meal about 4 - 6 units. Previously i was taking one night injection of 14 units of a 12hr insulin and then nothing in the day except fast acting when i ate (about 5 units/meal) . Since changing to the 24 hr lantus i have had a lot more highs than when i had no base insulin in the day.

Not sure what im doing wrong am i meant to split the Lantus ?

A split dose simply means to take part in the morning and part at night to make sure you have 24 hour coverage of Lantus. It could take a little tweaking, but one way to start off using a split dose is to take half at each time, that is 8 units in the morning and 8 at night. You might want to check with your doctor, but it really is commonly done.

You need to get your basal dose right first, and as others are suggesting, a split dose is usually better and Levemir is smoother than Lantus for many of us. Once your basal is covering you as closely as possible so your numbers are good between meals, at waking and at bed, then you can start tweaking your I:C ratios until those are more in line. It's really hard to do both at once because you can't tell what's causing highs and lows.

Hello and welcome! How was your control with the humalog alone? What was your average BG in mmol/L then? Your A1c from the humalog time would be helpful too to understand your current situation.

It sounds like you were taking NPH. You may have very different dosing between Lantus and NPH. As has been mentioned you need to determine your basal dose first, this can be done with basal testing. This is described in books like "Using Insulin" by John Walsh and "Think Like a Pancreas" by Gary Scheiner. A simple description is also on the Gary Scheiners site.

It is quite likely that before, the humalog you took during the day was partially acting as your daytime basal. And remember, once your blood sugars get high (like 22), you will need more insulin to bring your blood sugars down to normal.

Transitioning to a new insulin plan is not always "automatic". Sure it may be better on paper or according to the folks who sell insulin, but until you get things adjusted right, it can be tough!

If you are running high a lot of the time, it's not surprising it takes you more total units.

Lantus isn't a true 24 hour insulin but it is a lot longer acting than say NPH. I do Lantus twice a day (12 hours apart) with pretty good success spreading it out evenly. If I only had to do one shot a day it would not be so good.


I have personally just used Lantus at night (24 units, but I am male and weigh in at 85kg) and just use Humalog before each meal. As others have said, it is also common for people to spread the dosage over two shots (usually night and morning).

Hope this helps!


First: your lantus dose has to let you go to bed with a good BG and wake up with a good BG: is it so ?

Yogurt can have a lot of sugar, but mine usually is 13-16 carbs and you take 4U, it's a lot. Try to change site of injection, can you ?

Look and see how BG go in the afternoon, because lantus can fade away too soon. If this happens you can:
- get a bolus of humalog (with or without snack) in the afternoon or
- split lantus or
- use a mixed insulin at lunch (novomix 70/30, qhich has 70% of novolog and 30% of sort of NPH)

but if lantus is a 24 hr insulin and u split the dose doesnt it mean im getting a lot more in the day then at night ? if i take 16 units should i try split it ? is it too soon ? highs continued went to pilates and went up to 17 duno wat to do

First you have to get your base line set with the Lantus. then after you have a steady baseline 80-120 you have to readjust your use of humalog. Remember you already have a active insulin in your system so you won't be using the same amount of insulin as you did before. If you used to use 4 units for a yogurt before, I would start out at a 1/2 unit and check to see what your readings are and readjust from there on. Remember now you have a active insulin baseline and you have to find your new I/C scale (maybe you were 1/5 now you maybe at 1/20)

Also don't forget , don't use the same injection area as you are for the lantus, or you will be wiping out one or both of the insulins, they usually don't mix)

Good luck

The simplest way to split a dose is to take half at night and half in the morning, each dose 12 hours apart.

I never actually thought about where I inject humalog and lantus, but I routinely follow a morning lantus shot with a morning humalog shot and they are both in my stomach. I guess now I will actually think about where I am injecting before I inject. But I don't think I can remember a time when I wiped out the actions of either of my insulins regardless of where I injected them.

I too find lantus is not a true 24 hour insulin. I take 13-14 units in the morning depending on what kind of activity level I am expecting like if it is a weekend and I am playing golf I'll take 13 if it is a work day I'll do 14, then 13 at night regardless of the day of the week. But figuring it out has been a whole lot of trial and error - lows, highs and everything in between. Once you do get it "right" for you it is an awesome feeling just knowing what to expect makes life a whole lot less complicated. So keep at it and know you have a cheering section here to help as much as possible.

We do not split the lantus into two doses. I do not want to add an extra shot. We moved it to the morning. This has made a HUGE change for us. His night numbers have been FLAT. Sometimes we have to watch for a peak in the Lantus in the afternoon. Good luck!

I did that initially started taking the full 30 units in the morning and got immediate measurable results. Both from an A1C point 7.5 down to 6.9 with much less uncertainty, but it was still not optimized so the CDE and I looked through all my meter data and decided to split it. That has further increased control and taken the 6.9 down to 6.1 in a couple of months. It crept its' way back to 6.4 recently but I'm ok with that. Not having to constantly worry about the high/low roller coaster has improved my life immeasurably. I use a lantus pen and nano needles so the extra shot is incidental for me.

Hi Char. Your basal dose is set too high for the amount of Humalog you've been used to taking or you would not get those lows. It takes 3 days for BG to settle after starting it.
Do a basal test: don't eat breakfast the first day, and test every hour, record it; hold off on lunch til 12 so you get numbers thru 12. 2nd day skip lunch and test thru afternoon every hour; 3rd day, skip supper and test thru bedtime and it would be lovely to have a test during the night. Your basal should not cause a fluctuation of more than 30 all day and all night - or are you doing mmol?
This is your choice. The doctor sets the basal dose or you do it. And since you have to deal with it, do the testing so you know what that dose is doing to your BG. If he has a team, you can get some more consult from his CDE maybe.
While some do 1/2 at evening and 1/2 in morning, do not be surprised if you find you do better to have very little in the evening and a majority in the morning or vice versa. When you have test results from around the clock, you'll find a lot of people here can read them and help you interpret what to do next.
When you said you're taking Humalog about 4-6 units every meal, it sounds like your insulin to carb ratio is not established. How many units per carb gram is what you want to work with. And if you use non starchy veggies first to test that out, it's easier before seeing if your Humalog can cover starches/grains or can cover above 25 grams. It can't be worked out til the basal is tested thruout the day. You have to do trial and error and corrections for awhile.

Hi Leo & everyone else thanks so much for this . I havent done the Dafne course yet so no carbs ratio not really established . I read Dr Bernsteins book and am trying to eliminate carbs. I am a 28 year old Type 1 diabetic weighing 68kg and gym everyday. I am testing 10 units at 10pm and 10 units at 8am of Lantus, Then normally it is between 3 - 5 for other meals. But just seem to be yoyoing up and down. Should I reduce the Lantus ? You seem to know what you're talking about I feel lost ! Going away in 3 weeks and really want to have more control. Also noticed iv put on 2kgs in a week since starting Lantus ?? Now think I should switch to Levemeer - seen lots of posts about this. I will def try hourly testing and holding off - all tips are super appreciated.

I too am a fairly new user of Lantus, which replaced the NPH I used for decades. The change made a world of difference to me because it has helped eliminate the drastic lows that came as a result of NPH's uneven action; i.e., Lantus is more predictable.

I take more Lantus than NPH--my dose is 60 units in the morning. With NPH, I'd also take Regular to cover meals, whereas today I use Novolog (16 units before each meal). Sometimes I'll take a supplementary dose before bed, but I have to be careful not to overshoot (pardon the pun).

I hope this bit of information helps you somehow.