Humulin N 10 mL Vials Have Been Discontinued in Canada: What Diabetic Dog Parents Need to Know

In early September, I called Lilly Canada, the producers of Humulin N, and confirmed with a representative that the 10 mL vials will not be available. The representative told me that the 10 mL vial was a slow seller compared with the KwikPen and Humulin N cartridges.

The individual I spoke with had no idea that Canadian pet parents use Humulin N for their diabetic dogs under the guidance of their veterinarians. The rep wasn’t aware of this information, along with the prevalence of canine diabetes in North America. It’s estimated that one in 300 dogs will develop diabetes. 

There's an interesting bit of Canadian history here. Lilly Canada's offices are only a few kilometres from the University of Toronto, where Frederick Banting and Charles Best's early insulin research included experiments with diabetic dogs.

I had been trying to confirm the discontinuation since mid-summer and emailed Lilly Canada's media contact twice without receiving a response. Eventually, I called the company directly and spoke with a representative.

Humulin N isn't disappearing entirely. The change affects the 10 mL vial only in Canada. Other Humulin N formats remain available.

Options moving forward

It’s not easy to switch insulin types with a diabetic dog. It takes time, careful attention, and has to be done under the guidance of a vet. Here are a couple of options that may help in the immediate term.

Talk to your pharmacist about remaining supply

We were able to order several 10 mL vials of Humulin N from our pharmacist, which buys us time to plan long term. The unopened vials don’t expire until 2028 so we have lots of lead time. For Parker, we replace an opened vial after about a month, so our remaining supply should last us until next spring. We’re storing them at the back of the fridge – and not at the front or in the door – to ensure they remain at the proper temperature.

Consider the Humulin N cartridges

We’ve been in contact with our vet about the discontinuation of the vials. They did some research, proposing that the cartridges are an option. We haven’t tried them yet but will edit this article when we do. They noted a couple of shortcomings: the rubber seal is smaller than the vials, so it will require more precision with the needle.

The cartridges come in packs of five, with each cartridge containing 3 mL of insulin, so an individual cartridge may not last as long depending on your dog's dose.
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The manufacturer's instructions state that cartridges in use or not refrigerated should be discarded after 28 days, even if they still contain insulin. Those instructions assume the cartridge is being used in its intended delivery system, so if you're withdrawing insulin directly from a cartridge with a syringe, I recommend asking your veterinarian or pharmacist to confirm the appropriate storage and in-use period.

Several people in diabetic dog Facebook groups told us they use the 3 mL cartridges almost like small vials, withdrawing the insulin with their usual U-100 syringes rather than using an insulin pen. That’s particularly interesting for people with smaller dogs, since less insulin may have to be discarded when the cartridge reaches its recommended in-use period. If you’re considering this approach, check with your veterinarian or pharmacist first and ask them to show you the correct technique.

Another dog owner told us she actually prefers using a HumaPen because she finds it easier to administer a consistent dose, particularly when someone else needs to give her dog an injection.

The cost of switching

The cartridges are more expensive than the vials. To better understand this option, I purchased a package of Humulin N cartridges from our local Shoppers. Five 3 mL cartridges cost $66, compared with about $30 for a 10 mL vial. That works out to $4.40 per mL for the cartridges versus $3.00 per mL for the vial — about 47% more.

For dogs that use relatively small amounts of insulin, however, the smaller cartridge may mean less insulin is discarded. With Parker, for example, we were only using about half of a 10 mL vial before replacing it.

The math could be in your favour. I chatted with someone in one of the diabetic dog Facebook groups who figured a cartridge could last about three weeks for a smaller dog, depending on the dose. At $66 for five cartridges, that works out to roughly $230 a year — about $130 less than buying a $30 vial every month. Your actual cost will depend on your dog’s insulin dose and local pharmacy prices. And if you're of age, a senior's discount :)

Let Lilly Canada know this affects your dog

When I spoke with Lilly Canada, the representative wasn't aware that Humulin N is used by veterinarians to treat diabetic dogs. If your dog relies on Humulin N, you may want to let the company know how the discontinuation affects you. Lilly Canada's Customer Response Centre is 1-888-545-5972.

What about Novolin ge NPH?

Another option that has been suggested to us by several people who care for diabetic dogs is Novolin ge NPH. Like Humulin N, it is an intermediate-acting NPH insulin, although it is made by a different manufacturer — Novo Nordisk rather than Eli Lilly. Because both contain human insulin isophane (NPH), Novolin ge NPH may be an alternative for some dogs currently using Humulin N.

Novolin ge NPH is also available in a 10 mL vial in Canada, which may make it particularly worth discussing with your vet if you prefer to continue using a vial. Availability of specific formats can change, so check with your pharmacist about what is currently available in your area.

That doesn’t mean you should simply switch from one to the other on your own. Even when two insulins are similar, a change in insulin should be discussed with your veterinarian, who can advise you about dosing and whether additional blood glucose monitoring is needed during the transition. If the discontinuation of Humulin N 10 mL vials affects you, Novolin ge NPH is one option worth asking your vet about.

Don't make the switch on your own

If your dog currently uses Humulin N from a 10 mL vial, there's no need to panic — but now is a good time to make a plan. Talk to your veterinarian and pharmacist about how much vial inventory remains in your area and whether Humulin N cartridges or another option may be appropriate for your dog.

Most importantly, don't change your dog's insulin, dose or routine without guidance from your veterinarian. Switching insulin or changing how it's administered may require additional blood glucose monitoring while you determine how your dog responds.

We're navigating this change with Parker, too. For now, we have enough Humulin N vials to give us time to consider our options with our vet. If we move to the cartridges, we'll document how it goes and update this article with what we learn.

If your diabetic dog uses Humulin N in Canada, we'd also love to hear what your veterinarian or pharmacist is recommending. We'll continue updating this article as we learn more — including what we learn as we navigate the change with Parker.

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