Shipping medication refrigerated: how to keep your parcel at 2-8 degrees
If you want to ship medication refrigerated, you face one hard requirement: the product must stay between 2 and 8 degrees, from the moment it is packed until the moment the recipient opens the parcel. In the meantime, that parcel sits in a sorting centre, in a delivery van and sometimes for an afternoon on someone's doorstep. The packaging is the only thing in that chain you control yourself. This article explains how to build up that packaging, where it goes wrong and what to look out for when you ship pharmaceutical products refrigerated for the first time.
Why 2-8 degrees is such a tight margin
With medicines that require refrigeration, everyone thinks of heat, but the lower limit is just as important. Many biological medicines, including insulin and GLP-1 medication, cannot tolerate freezing. A gel pack straight from the freezer lying against the product is colder than zero degrees and can therefore make the product just as unusable as a hot day. The task is thus twofold: keep heat out and prevent freezing. That determines almost every choice in the packaging.
On top of that: wholesalers and pharmacies working under GDP guidelines must be able to demonstrate that the temperature stayed within the margin during transport. Packaging that "usually works out fine" is not enough then; you want a build-up you have tested and repeat in the same way for every shipment.
Cold chain packaging for medication: the basic build-up
The combination that has proven itself in practice is a polystyrene box (EPS) with gel packs or cool packs. Each component has its own job.
The polystyrene box insulates
EPS slows down the heat exchange with the outside. The thicker the wall, the longer the inside stays at temperature. For shipments that travel overnight, you choose a different wall thickness than for a shipment that takes longer. The fill level matters too: a half-full box contains a lot of air, and that air warms up faster. Fill empty space, for example with extra filling material, so the climate inside the box stays stable.
The gel packs deliver the cold
The insulation only holds the temperature; the gel packs or cool packs make sure there is something to hold on to. How many you need depends on the volume of the box, the wall thickness, the transit time and the season. You pack differently in summer than in winter: a fixed summer and winter configuration prevents every employee doing it by feel.
Conditioning prevents freezing
This is where things most often go wrong in practice. Gel packs straight from the freezer are too cold for direct contact with a freeze-sensitive medicine. Two common solutions: let some of the gel packs come to temperature in the fridge first (chilled instead of frozen packs close to the product), or create a buffer between pack and product, for example a layer of cardboard or filling material. The product must never lie directly against a frozen pack.
Shipping pharmaceutical products refrigerated: the common mistakes
- Too little cooling capacity for the actual transit time. Don't count on the best-case scenario, but on the parcel that sits for a day or is delivered to the neighbours.
- Frozen packs directly against the product. See above: freezing is just as damaging to these medicines as heat.
- A half-empty box. A lot of air in the box means rapid temperature swings.
- Never measured. For the first shipments, put a temperature logger in the box and read it out on arrival. Then you know what your packaging really does in your shipping flow, instead of assuming it.
- Shipping on Friday. A parcel that spends the weekend in a depot is an unnecessary risk for a cold chain. Match your shipping days to the transit time.
Shipping GLP-1 medication: why this matters now
Online pharmacies, weight loss clinics and telehealth providers increasingly ship GLP-1 medication based on semaglutide or tirzepatide (brands like Ozempic, Wegovy, Mounjaro and Saxenda) directly to the patient's home. These medicines require refrigeration and are freeze-sensitive, and the recipient is a consumer without a loading dock or cold store: the parcel must still be within the margin after a day in transit and a few hours on the doormat. The same rules as above apply to the packing, but the margin for improvisation is smaller. Anyone doing this daily wants one validated box configuration per size and season, so every shipment is packed identically. We make no statements about the medicines themselves; that is up to the pharmacist and prescriber. Our trade is the box around them.
Choosing the best cold chain packaging for medication
There is no packaging that is best in every situation; there is, however, a short list of questions that leads you to the right choice:
- How long is the parcel in transit at most? Including delays, not just the carrier's standard transit time.
- How big is the product and how much goes into each shipment? That determines the inner size and thus the box.
- Is the product freeze-sensitive? At 2-8 degrees almost always: then conditioning or buffering belongs firmly in the packing instructions.
- Do you ship all year round? Then record a summer and a winter configuration.
- Do you need to be able to prove it? Test the configuration with a logger before you scale up, and repeat that test whenever you change something in the build-up.
Once you have answered these questions, for a 2-8 degree shipment you almost always end up with a polystyrene box in the right wall thickness with a fixed set of gel packs or cool packs, packed according to instructions that are the same for every employee. Not exciting, but reliable, and that is exactly what you want with medicines.
Not sure which size or configuration suits your shipments? Our webshop carries insulated polystyrene boxes, gel packs and cool packs in various sizes, and we are happy to send a sample so you can first test the combination yourself with your own product and your own shipping flow.
