I would go with Lantus if I had to choose because it has the most research proving it's effectiveness and the best statistics at getting cats into remission BUT it's expensive in the US.
Also, Lantus/Basaglar (both are brand names of Glargine insulin) are U100 insulins so you could continue to use the same syringes. If you go with ProZinc, you'll need U40 syringes
Most of us are buying ours from Canada because it's 1/3 to 1/2 the cost, but it'll take about a week to get it. Here's
info on buying Lantus (or Basaglar which is also "glargine" insulin but a little cheaper) from Canada
Buy the cartridges or pens....they're the best buy.
Your vet may have ProZinc in the office to sell you (it can also be bought from Chewy for about $107) but again, that would mean waiting for it to get shipped.
So basically, if you want to change insulin's immediately, you'll either have to pay about $290 for a vial of Lantus (half of which you'll end up throwing away) or paying whatever your vet charges for ProZinc (if he has it available there)
Or you could continue with the Novolin while waiting for shipment of one of the better insulin's. You'll can have your vet either fax a script to Marks in Canada (for Lantus or Basaglar IF he has no objection to buying from Canada) or to Chewy (for ProZinc) or
you can just ask for a written script so you can do some "shopping around" for the best price. (you can take a picture of it and send it to Marks)
Some vets don't approve of buying insulin from Canada but as long as you can get a written script, that's all you need.
