Cold-chain shipping for medicines: what 2–8 °C really means

What the cold chain is

The cold chain is the unbroken sequence of refrigerated storage and transport that keeps a temperature-sensitive medicine between 2 and 8 °C from the moment it leaves the manufacturer until it is used. It covers the wholesaler’s warehouse, the pharmacy refrigerator, the courier’s insulated box and, finally, the patient’s own refrigerator.

The requirement exists because many modern medicines are proteins or peptides rather than simple chemical compounds. Heat makes proteins unfold and clump together, which can reduce the dose that actually reaches the body and, in the worst case, provoke an immune reaction against the medicine. The change is invisible: a warmed pen or vial looks exactly like an intact one.

Which medicines need it

Three groups of medicines in our catalogue must stay refrigerated:

• Biologics, above all monoclonal antibodies: adalimumab, infliximab, bevacizumab, pembrolizumab, dupilumab, evolocumab and trastuzumab deruxtecan.
• Peptide hormones and analogues: insulin lispro, the GLP-1 receptor agonists semaglutide, liraglutide and dulaglutide, the dual GIP/GLP-1 agonist tirzepatide, somatropin, octreotide and lanreotide.
• Vaccines: hepatitis A, the hexavalent infant vaccine, HPV, inactivated influenza, MMR and typhoid, together with intravesical BCG.

Small-molecule tablets and capsules such as metformin, empagliflozin, rivaroxaban or the CFTR modulators are stored at room temperature and travel as ordinary parcels. The storage temperature and the cold-chain requirement are listed in the key facts of every medication page on this site.

Why freezing is as dangerous as heat

A refrigerated shipment can fail in two directions. Too warm, and proteins degrade. Too cold, and they freeze, which is usually worse: ice crystals break the structure of a protein irreversibly, and for aluminium-adjuvanted vaccines such as hepatitis A or the hexavalent infant vaccine, freezing destroys the adjuvant that makes the vaccine work. A vaccine that has been frozen must be discarded even if it has thawed and looks normal.

This is why a well-built refrigerated parcel keeps the medicine away from direct contact with the cooling elements, and why the product information for every refrigerated medicine repeats the same instruction: do not freeze.

How a refrigerated parcel is built

A cold-chain shipment is an insulated outer box with cooling elements inside it. The number and type of gel packs are chosen for the longest expected transit time to the destination, not the shortest, so that the contents stay within range even if the parcel is delayed. The medicine sits in its original carton, which protects it from light and from direct contact with the cold packs. Tamper-evident seals and discreet outer packaging complete the parcel.

For international shipments, the documentation matters as much as the packaging: a commercial invoice, the customs declaration and, where required, the prescription and medical documentation travel with the parcel so that customs processing does not add days to the transit time.

Room-temperature allowances by product

Manufacturers test how long their product tolerates temperatures above 8 °C, and the result is printed in the product information. The table summarises the allowances stated in the product information of medicines in our catalogue. They are a safety margin for transport and daily use, not a storage recommendation, and the exact figures vary between brands and presentations, so always follow the leaflet of your specific product.

Medicine	Allowance stated in the product information
Adalimumab (pen or syringe)	A single period of up to 14 days at up to 25 °C
Dupilumab (pen or syringe)	Up to 14 days at up to 25 °C in the original pack
Evolocumab	Up to 1 month at up to 25 °C in the original carton
Infliximab (vials)	A single period of up to 6 months at up to 25 °C, within the printed expiry
Insulin lispro (in use)	28 days below 30 °C
Semaglutide (in use)	4 to 6 weeks below 30 °C, depending on the formulation
Tirzepatide (in use)	21 days below 30 °C
Liraglutide (in use)	30 days at or below 30 °C
Dulaglutide	14 days below 30 °C
Octreotide ampoules	Up to 2 weeks below 30 °C
Lanreotide (sealed pouch)	Up to 72 hours below 40 °C before injection
Hepatitis A vaccine (Havrix)	Stable for 3 days at up to 25 °C

Two things are worth noticing. First, a pen that has been taken out of the refrigerator once should not be put back and taken out repeatedly; most leaflets say that once removed, the product must be used within the allowance or discarded. Second, the allowance applies to the whole life of the product, so a parcel that used part of it in transit leaves less margin for daily use.

What to do when the parcel arrives

Open the parcel promptly and check the cooling elements: they should still be cold to the touch. Check that the medicine has not frozen, then transfer it to a refrigerator at 2–8 °C in its original carton. Keep it in the main compartment rather than in the door or against the back wall, where temperatures swing most. If anything about the condition of the parcel or the product worries you, contact the sender before using the medicine; a photograph of the parcel and its contents helps.

How we handle refrigerated shipments

Every refrigerated medicine we coordinate is shipped in insulated packaging with cooling elements sized for the longest expected transit to the destination, with tracking and customs documentation prepared before dispatch. Import rules for medicines differ by country, so we confirm that a shipment is feasible for your destination before anything is sent. The delivery page describes the packaging standards and documentation in more detail.