View Full Version : Humulin vs. Novolin N causing lows - anyone else?

02-06-2011, 08:48 PM
I have used Merick (certified low glycemic) and Origen ( also certified low glycemic). Both foods work well but I found a raw dog food and the Origen dry dog good to be my best combination.
The food and insulin regiment worked well for over a year. Thenl Wal-mart changed their contract with Novolin N Insulin and started Humulin N. They told me there would be no difference and all of a sudden, I was dealing with too low blood sugar and now trying to regulate I have been too high. I'm changing back to Novolin N today, but want to know if anyone else has experienced this. I'm hoping I'm not dealing with her becoming insulin resistant. Anyone have any answers for me?

02-06-2011, 10:46 PM

Welcome to the forum!

I copied your question to its own thread so it will get more responses.

And I'm sorry to say that I have been getting quite a few reports similar to yours - with the Humulin N seeming to be more potent than the Novolin N and doses having to be decreased.

Which really surprised me because four or five years ago I saw a lot of dogs switching back and forth with the two insulins behaving pretty much identically. For whatever reason, that no longer seems to be the case and I think we will have to start advising people to do maybe a 20% reduction in the insulin dose when switching from Novolin N to Humulin N, whether through Walmart or for some other reason.

Maybe a more important question is whether the regulation is still good once the insulin dose is reduced? Having to give a little less insulin is only a problem if it's not generating the same quality of regulation.


02-18-2011, 10:12 PM
Just popping this up to the top of the list.

02-19-2011, 09:17 AM
I have only been using the Humulin for a couple of months (my Wal-Mart had a lot of Novolin to use up) but I have had to increase the dose from 34units to 35units and test more often. Taylor seems to be running much higher for the most part but throwing me a low every once in awhile when I least expect it. Iím not sure I am ready to pay the higher price, but things were better on the Novolin. Pat

jesse girl
02-19-2011, 09:35 AM
jesse doesnt exactly work well with either as far as staying constant and predictable there are things we do to keep her in good numbers but you cannot get comfortable and take things for granted I could leave her in the 300s and 400s but that will not be good so I try to keep her in the 100s and can do most of the time but she can get those low times out of the blue and highs . I wish there was something more constant maybe its just the way her body works with the insulin (it wasnt developed for dogs ) and thats as good as its get until something else enters the market ( after the vetsilun problems there may not be anything else designed for dogs)

This creates a scenario that I have to test her quite a bit I wish that wasnt the case but thats the trade off for keeping her in better numbers i guess

Norma Jean
02-23-2011, 02:27 PM
I have only been using the Humulin for a couple of months (my Wal-Mart had a lot of Novolin to use up) but I have had to increase the dose from 34units to 35units and test more often. Taylor seems to be running much higher for the most part but throwing me a low every once in awhile when I least expect it. Iím not sure I am ready to pay the higher price, but things were better on the Novolin. Pat

Yes Pat, I had a terrible time with the switch with higher numbers and irregular curves and had to return to the Novalin N and things are definately better. It will be interesting to see if more and more have this problem. It is supposed to be the same but after 3 months of trying everything to figure it out I was done and now back to Novolin. Back to reads between 100 to 264. Good Luck, Norma Jean

02-23-2011, 03:20 PM
With Mildred it was as simple as a slight reduction in her insulin dose when I switched her over to Humulin N.
And, I can not even say for sure it was the insulin and not just her body ready for a change, and in this case, a reduction in insulin.
Her great numbers continue now on Humulin N.

A friend of mine who is a homeopathic doctor and who teaches diabetes awareness and education, who has a recently diagnosed dog herself, suggests that if there were any significant difference between Humulin N and Novolin N they would not both be NPH insulin.

02-24-2011, 10:15 PM
I agree that there shouldn't be a significant difference and I've said for years that they are interchangeable even in terms of dosing.

But I've gotten a handful of reports from people transitioning from Novolin to Humulin who are finding that they need to give less units of the Humulin. Strictly anecdotal but in much higher numbers than I would have expected.

So in the name of caution, I would now recommend that the dosage be lowered some... not more than 20%, maybe more like 10% or a unit or two... when making the switch just in case there is a difference.

You never know what might be happening with the manufacturers - Vetsulin has certainly taught us that. These insulins are not much of a profit maker for the drug companies as they are long out of patent - they would much rather be selling Lantus, Levemir, Novalog, etc.

It will be interesting to see how it plays out.


02-24-2011, 10:31 PM
I can't help but think that in some cases if blaming the insulin has just become a 'scapegoat' for other actual issues.

02-25-2011, 02:16 AM
Eileen - I think if a person is keeping careful observations and GOOD RECORDS - blaming the insulin MIGHT make sense. I once wondered about my vial of Novolin, whereupon Novo Nordisk tested my vial free of charge. The insulin was good. So much for that one! It's a reputable company, and I'd never had trouble with Novolin-N before, and there WERE other possible causes.

However, if record-keeping is sloppy, blaming the insulin REALLY doesn't make sense at all. The place to start is, understanding the difference between data (observed phenomena, carefully-recorded) and interpretation. It's not possible to interpret sloppy data and at the same time, expect to come up with facts.

Sometimes insulin does go bad; as Natalie has pointed out - often, in transit (shipping), and we've all probably heard how, at times, clerks in pharmacies mis-handle insulin. Percentages for damage caused by such mis-handling are probably fairly low, and/or scattered, maybe depending on the pharmacy.

Just had one other thought. Our own memories notoriously betray us, so record-keeping needs to be done on the spot at the moment the data are available, and (again) done with care and attention.

So, a first step is to check one's own observations and record-keeping. If we tighten that up, then we might reasonably start questioning the vial we have.

Fri, 25 Feb 2011 01:14:58 (PST)

02-25-2011, 08:45 AM
I absolutely agree, Carol. With careful record keeping and with knowing what one is seeing it may be determined whether it could be the insulin or not.

Lately tho, on other groups, I've seen where one member might mention the possibility and it seems that quite a few will jump in with saying the same, these that I know are doing so many different things that have their dogs going in all directions that it is very unlikely it is because of the insulin...but yet the blame is put on the insulin being Humulin N.

03-27-2011, 05:41 PM
Changing from Novolin N to Humalin N was a real challenge
for my Miniature Schnauzer Mosby. He was pretty well regulated
on Novolin N, but when we switched to Humalin N we tried for 3
months and could never get him regulated. We kept his food,
feeding schedule and exercise all the same... So we were not
making changes all over the place. We tried giving less insulin
and tested daily and did many curves but just could not get him
out of the 300s and sometimes 400s. We finally switched back to
Novolin N and he was back in the 100s after one day.

I know some people had no problems switching but some do so
Each of us has to do what works for us. I'm sure Humalin is a very fine
Insulin but it did not work for us.

03-28-2011, 11:37 AM
I'm still having big problems with the switch, but I'm using 70 units a day and cannot afford $70 a vial for the novolin N. It's been a year and a half and I feel like I'm back at square one. Pat

03-28-2011, 11:50 AM

Do you have a curve you could post? We might be able to help you improve the situation if we can see what the blood sugar is doing.

The insulins are the same in terms of chemical composition so if your dog responded to human insulin in Novolin, he will respond to human insulin in Humulin. The levels might be different or you might need more or less units... the shape of the curve could change. Those are things that can often be worked with by way of other kinds of adjustments like diet and timing.

So please post your most recent curves (as many as you can since multiple curves give us trends).


03-28-2011, 11:52 AM

I'd really appreciate it if you could post curves for your dog also. In order to understand what might be going on between Humulin and Novolin N, we could use all of the data we can get.

I wondered whether, for example, the curves for Mosby were flat 300s and 400s so perhaps more of the Humulin was needed or whether the curves got "deeper" swinging from 400 down to 100 and back up again.


03-28-2011, 04:49 PM
Interestingly, a few weeks ago, when I had Sparky's numbers taking a nose dive, I spoke to the vet and he said that other "patients" were having similar problems with Humulin N. Hmmmm.......

04-03-2011, 06:22 AM
I am having good results with a return to novolin-n. See Taylor's thread for curve data. Pat

09-13-2012, 10:14 PM
This thread has a few accounts of problems people had making the switch. Not common but there were some reports.


09-27-2012, 01:25 PM
Bumping this up also.

03-22-2014, 08:40 PM
Hi there.

Is Novolin N still available at Walmart?

I am on my last one and am afraid to change to Humulin N when reading people having problems with changing.

I have it on hand humulin N, how did everyone change?

Dose to dose with q 2 hour sugar checks? For how many days? I know it takes 5 days to see a difference correct?

Please help! Thanks!