Storing & Travelling With Pet Insulin

Storing and travelling with your pet's insulin

Insulin is a delicate medicine, and looking after it properly is one of those quiet things that makes everything else work. The frustrating part is that mishandled insulin looks exactly the same — it just quietly stops working as well. Here's how to keep it right.

Storing it at home

Keep insulin refrigerated and never frozen — freezing damages insulin permanently. Store it in the main body of the fridge rather than the door, where temperatures swing every time someone reaches for the milk. Check the expiry date, and note your specific product's guidance on how long it lasts once opened.

Mixing: follow your insulin's leaflet

Insulins are mixed in different ways — some are rolled, some must be shaken — so always follow the package leaflet for your pet's insulin and your vet's instructions. Mixing it the wrong way can leave the dose uneven from one injection to the next, so check rather than assume — and ask your vet to show you if you're unsure.

How to tell if insulin has gone off

Insulin that's been frozen, overheated, mixed the wrong way or kept past its in-use date can lose strength. Some types show it — clumping, discolouration, frosting on the glass — but often there's no visible sign at all. If your pet's control suddenly worsens for no obvious reason, a tired or mishandled vial is worth mentioning to your vet.

Travelling with insulin

Very doable with a little planning. Carry it in an insulated cool bag with a cool pack that doesn't directly touch the insulin (contact can freeze it). Never leave it in a hot car. Take more supplies than you'll need, keep a copy of the prescription, and hold injection and meal times as steady as you can. Flying? Insulin goes in hand luggage — never the hold, where it can freeze.

Mello keeps the record of the routine — what was given, when, and by whom — wherever you are, and works with no signal. Premium can also remind you to reorder a prescription before the supply runs out.

Sources

The pages below were each opened and checked before being listed here, and anything that could not be opened was left off rather than guessed at.

• Caninsulin 40 IU/ml: package leaflet (Vm 06376/4083) — Veterinary Medicines Directorate, Defra, approved February 2026. Upright in the fridge at 2–8 °C, never frozen, below 25 °C once opened, 42 days in use — and that this product is shaken.
• ProZinc 40 IU/ml suspension for injection for dogs: package leaflet — Veterinary Medicines Directorate, Defra, year not stated. The same storage rules but 60 days in use — and that this product is gently rolled, not shaken. Read beside Caninsulin, this is the proof that mixing instructions genuinely differ by product.
• Client Education (Section 8) — 2026 AAHA Diabetes Management Guidelines for Dogs, 2026. An independent consensus statement that some insulins are shaken and others rolled, which is why the leaflet in the box beats any general rule.
• HUMULIN I 100 IU/ml: Summary of Product Characteristics — electronic medicines compendium (emc), Eli Lilly, revised August 2026. For the human insulins sometimes used off-licence in cats: 2–8 °C unopened, never frozen, kept out of excessive heat and direct sunlight, 28 days in use, rolled rather than shaken hard.
• Caninsulin 40 IU/ml Suspension for Injection — MSD Animal Health UK, prepared October 2024. UK manufacturer confirmation of the in-use period for broached vials and VetPen cartridges.