How should Wegovy be stored if not kept cold?

After first use, a pen can usually be kept below 30 °C (cap on, away from light) for up to 6 weeks — then it must be discarded, even if medicine remains. Unopened pens belong in the fridge; if they have been kept at room temperature on purpose, many packs allow a limited period out of the fridge — your leaflet sets the exact limit. Never freeze, never overheat (hot cars, radiators, direct sun), and never store with a needle attached.

Why storage rules matter

Wegovy (semaglutide) is a protein-based medicine. Like other biological treatments, it is highly sensitive to temperature, light, and handling. This is why its storage rules are so strict. If exposed to heat or cold outside the recommended range, the medicine can lose strength even though the liquid looks unchanged. NICE TA875 and MHRA product information confirm that stability studies underpin the rules: 2–8 °C in the fridge until first use, and up to 6 weeks at room temperature below 30 °C once opened. These conditions protect the integrity of the medicine, ensuring it works as intended.

After first use

Once you start using a pen, it no longer needs refrigeration. Instead, it should be capped and kept at room temperature, provided the temperature does not exceed 30 °C. This is practical for everyday life — pens can be stored in a drawer or cupboard out of direct sunlight. NHS services advise patients to write the date of first use on the carton, so the six-week “discard clock” is easy to track. After six weeks, the pen must be thrown away, even if it still contains some solution. This cut-off reflects manufacturer testing that shows potency cannot be guaranteed beyond that point.

Risks of overheating or freezing

Extreme temperatures are the main threat to Wegovy pens once they are out of the fridge. Heat accelerates protein breakdown, while freezing permanently damages the structure. NHS weight management teams warn patients never to leave pens in hot cars, on windowsills, or near radiators. Similarly, storing them in the freezer — or too close to the freezer compartment of a fridge — ruins the medicine. If a pen is suspected to have been frozen or overheated, it should not be used and should be disposed of safely in a sharps bin. MHRA safety advice emphasises this point clearly in patient information leaflets.

Unopened pens and flexibility

Unopened pens should normally stay in the fridge between 2 °C and 8 °C. However, manufacturers often allow a limited period outside the fridge if necessary, for example during travel. The exact limit is printed in the leaflet included with each pack. For most batches, it is up to 6 weeks at room temperature below 30 °C. This flexibility is designed to make holidays or longer journeys manageable, but it is not meant for routine storage. NICE and NHS guidance remind patients that the safest option for unopened pens is refrigeration until needed.

Practical tips for everyday life

At home, many patients keep unopened pens in a labelled container in the fridge, away from the freezer compartment and food that might contaminate them. In-use pens are best stored in a cool cupboard, kept in their original carton for light protection. NHS patient education often includes advice on small details: never store pens with a needle attached, as this can let air or contaminants into the cartridge and cause leaks. For added safety, check pens before use — if the solution looks cloudy, discoloured, or contains particles, it should not be injected.

Travel and warmer climates

For those travelling abroad or during UK heatwaves, extra care is needed. In-use pens may tolerate up to 30 °C, but temperatures above this are common in hot climates. Portable medical coolers or insulated pouches can keep pens safe without freezing them. NICE and NHS guidance emphasise that planning ahead is part of safe use: know how long your journey will take, keep pens in hand luggage, and avoid leaving them in cars or checked baggage. These precautions ensure treatment continues smoothly even outside routine home conditions.

Linking storage to treatment success

The STEP and SELECT trials that underpin NICE approval used pens stored and handled under strict conditions. This ensured every participant received full-strength doses. NHS guidance reflects this by emphasising safe storage as part of treatment education. Patients who follow the rules protect their investment in both medicine and lifestyle changes, while those who cut corners risk reduced effectiveness. A pen that looks fine but has been left in direct sun may no longer deliver the full benefit. Safe storage is therefore not just a technical detail but a way of protecting long-term results.

How guidance reflects this

Storage guidance for Wegovy is based on robust research and regulatory review. NICE TA875, MHRA licensing information, and NHS patient leaflets all align on the same principles: refrigerate unopened pens, keep in-use pens below 30 °C, discard after 6 weeks, and never freeze or overheat. The rules are designed to match the conditions used in clinical trials, ensuring patients in real life receive the same quality of treatment. How guidance reflects this is simple but important: these rules are not optional extras, but part of the treatment itself, safeguarding both safety and effectiveness.