Many vets will write a script that you can fill at your pharmacy.
If I needed a sensitive thing like insulin it’s what I’d go for.
Thing is you don’t need a prescription for human insulin. You just walk up and buy it. Now a Vet might tell you a prescription is needed but it’s not.
They might also tell you to leave your dog with them all day once a week to monitor their glucose levels until they are right at $200 dollars a day.
Humans monitor their own sugar levels all the time by themselves without a vet to do it for them. If you have a diabetic Dog you are going to have to do this all the time anyhow. :)
Yeah? Just Try to get it. I have friends with diabetic cats paying 6 times the cost for insulin. When I had a kitty with hypertension I was paying $4. PER PILL for Norvasc at a vet clinic, until I got a vet who would give me a script & got about 10 pills for that $4.