Mixing insulin - type 1

I have had diabetes 53 years and have always combined my long-acting (lantus) and my short acting (Humalog) in the same syringe. My friend, whose daughter was diagnosed 6 months ago, said they were told not to mix insulins because the long acting blocked the effectiveness of the short-acting. Her DD is on Humalog pens and has to take Lantus separately.

Have you been told something similar? I have had (for me) good A1cs. What do you other non-pump users do at this point? Thank you.


Have not mixed insulin in a long time. The last time I was on 2 types of insulin it was lantus and humolog. I used a pen for Lantus and a syringe for Humolog. Reason given so I would not mix them up

Edit: I took R and NPH also and mixed them before the 70/30 mix came out

I mixed my NPH and Regular for many decades (not quite as much of an old-timer as you, just 39 years for me!).

But when I started Lantus+Humalog everything said not to mix.

I just switched to pens a few years ago. Still kinda like the old syringes better.

If you take Tresiba by syringe, it is OK to mix short-acting with it.



I take Lantus… Wow… I feel like Rip Van Winkle… going to write to my doctor…


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ame-e, I used insulin and syringes for decades. I finally switched to pens a few years ago and like them much better for ease of use. You might like them.

I had learned that you should never mix the newer insulins, and I don’t but I googled mixing the insulins you are using and apparently it is ok to do what you are doing.

Thank you. I just wrote to my doctor. Have to see if insurance will cover pens…


In my early days I mixed lente and regular to make its own medium acting insulin. However when the newer Analogs and Lin insulin’s came out it was suggest we no longer mix. In the case of lente and regular insulin’s they contained additives like zinc to slow the process of the basic structure. Current insulin’s do not use these suppressants.

I used to be on Lantus and Humalog prior to switching to OmniPod pump. And, yes, I was told NOT to mix Lantus and Humalog. My doctor told me to use a separate syringe for each insulin type. I reused my syringes, but I did NOT MIX insulin in the syringe.

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Thank you everyone. I am talking to my doctor. this makes me think about the pump as I don’t want to take 5-6 shots a day. 4 is bad enough. I am a little overwhelmed right now by it.

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That was why I moved to pumping. I was taking 8-10 injections a day and it was exhausting. I like to take small corrections after meals if I’m still higher than I like, so a pump is a better fit for me.
I still make a lot of corrections and my pump makes a few automatic ones.
And I don’t have shits with tiny blood spots all over them like I used to.
I know a lot of people who prefer the injections, I guess it’s all,about what you like best

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When I started, Humulin had just come out, and I took R and U.
Before, there was R, NPH, L, and U, but L and U are no longer on the Humulin web site so i guess they are no longer being produced.
When Humalog first came out, the instructions said it could be mixed with NPH, but nothing else. So my endocrinologist switched me to Humalog and Humulin NPH, and I always mixed to minimise the number of times I had to jab myself. I did that for 30 years. Then my endocrinologist said to switch to Tresiba, and my pharmacy only sells the pens, so mixing is impossible. Advice is to use separate syringes and needles for a long acting insulin and Humalog, but (like just about everything else) some say it’s OK to mix (but if I were doing it, I would use separate syringes).

I took ultra lente too, and it was discontinued prob around 1995 which is when I went to a pump.
I seem to remember that the no mixing rule started when glargine started. Since I was off it, I never experienced it.
I bet taht you could mix them someone could do an experiment and see how it works both ways.

I took U as well. It had an interesting profile As I recall it it woudl work for 18- 20 hours and many times not as much. So how do you figure out how to work on the gap? Those were the days.

Great question & your experience shows us that we are all different. I’ve known families that DO mix the Lantus with the fast acting to ease the number of injections for their children & the sugars Are where they want. I believe the key point is to just find the dose that works & be consistent. So the insulin is a bit different if you mix, but the change / action will be consistent for YOU… As your A1c has shown, it can work fine. I also mixed my N & R way back in 1965. Then began pumping in 1988. We’ve learned much & not all that does work is “approved by FDA”. It just needs to work safely for you.

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For 25 years I took separate doses of Lantus and fast acting because my doctor told me they are a different pH. So one dilutes the other. But I suppose by increase the doses it would compensate. I also split my total Lantus dose taking most of it before breakfast and a smaller dose at dinner because by blood sugars would often rise by morning! (I am on the OmniPod and love it using only Humalog.)

Thanks. I am thinking of switching to the pump, but am a little intimidated. Plus I turn 65 this year, and I’m wondering if the Medicare insurances will cover it without my paying a ton of money a month. Thank you for everyone’s feedback.

I started with single Lente only in 1965, and switched to NPH + Reg multiple daily injections in late 80s, then started pump with Regular. Now using the faster acting Novolog with Tandem pump. The changes and new tech and meds is evolving much faster now.

Humalog specifically warns that it may only be mixed with Humulin NPH. The package insert says it must never be mixed with any other insulin than NPH in a syringe, and must never be mixed with any other insulin in a pump.

Some people say they have never had any trouble mixing a long-acting analog insulin with Humalog, but it is not recommended.

So the update is I am no longer mixing them and am looking into getting an i-pen which is supposed to coordinate with my CGM. I am running lower sugars now in the morning so need to adjust my dose. Thank you every one for your support. It is so comforting to be on a forum with other people who have the disease!


Ame-e, Medicare will cover a pump and the insulin for it under Part B. You will need to see your Doc quarterly to certify your continued use.