Insulin Options

The 2 most common types used are Vetsulin and Novolin N.


Some vets will tell you you can only use Vetsulin (Caninsulin). That may not be the case.

Reasons why to choose Novolin N over Vetsulin

Novolin N is sold at Walmart for $24.88 and does not require a prescription. That’s a huge saving.


Novolin N sometimes works better on smaller dogs because Vetsulin is an aqueous suspension containing 35% amorphous for rapid onset and 65% crystalline zinc crystals in a neutral buffer of pH 7.35.

     -   Smaller dogs tend to have a faster metabolism, and the rapid onset portion of Vetsulin can rush insulin through the system          and cause a low drop in BG after injection. 


Novolin N won’t necessarily have this same concern. 

Other reasons for switching, affordability, and availability. 


Vetsulin (shake) they changed it about 7 years ago. Shake thoroughly until uniform milky throughout. Not foamy. 

Vetsulin was taken off the market in 2010

When it was brought back in 2013, it changed to shake to mix.

Both can work, and one isn’t necessarily better than the other. And novolin is not inferior to Vetsulin. However, use what you’re comfortable with if you are concerned about price and convenience or have a smaller dog. Ask about other options. 


HOWEVER, different insulin requires different types of syringes.  

Vetsulin needs U-40 syringes (Red cap)

Novolin needs U-100 syringes (Orange cap)

Using the wrong needle can be dangerous


Some states require a prescription for the needles at Walmarts, even if you don’t need it for the insulin. You can order needles online as well without a prescription. 


If you plan on switching to Novolin N from Vetsulin...


Drop insulin dosage down a unit because novolin is a different strength. You don’t know how your dog will react to it, so go in aware that your numbers will change. If your numbers appear higher after the switch, be careful not to increase. Allow for the transition, expect different numbers (if numbers are the same great.) and run a curve 5 to 7 days after to see how you're responding and adjust accordingly. High dose increments.

Humulin N and Novolin N are both brand names for the same drug (NPH). Both intermediate-acting

Another Insulin type is Levemir - Detemir.

It's long-acting and used if the dog metabolizes the intermediate too quickly.  

Is about 4 times stronger than Novolin.

What if My vet tells me I can't use Novolin because it is meant for humans...

In 2011, Vetsulin was taken off the market, and dogs had no choice but to use human DNA-derived insulin (Novolin, etc.). There aren't any documented adverse effects of using human DNA-derived insulin on canines. 

So, human DNA-derived insulin has successfully been used on canines for years and can be and was, at one point, the only option. And for many, it is a necessary alternative because of the cost. 

However, there are no guarantees that human DNA-derived insulin will have the same effects as Vetsulin (Caninsulin). It is potentially a great option to consider. Your vet should be willing and open to working with you on your options.