People using weight loss jabs have been issued an alert by a doctor as a heatwave approaches, with reminders that improper storage could lead to costly issues. Drugs like Wegovy and Mounjaro must be kept in the right conditions to preserve their active ingredients. These injections are biological, protein-based medications that are highly fragile and can spoil if exposed to excessive heat, potentially rendering them useless or unsafe. For those purchasing privately, a single pen can cost up to £300, making proper storage essential.
Storage Guidelines for Weight Loss Jabs
Although Wegovy and Mounjaro are different drugs, they share similar storage instructions. Unopened pens should be refrigerated. Once in use, they can be kept out of the fridge but must still adhere to strict temperature controls. Dr Kathryn Basford, from Asda Online Doctor, explained: “For Mounjaro to remain effective and safe, it ideally needs to be refrigerated between 2°C and 8°C. It can be stored unrefrigerated for up to 30 days, so long as it doesn’t go above 30°C.”
“If your Wegovy pen is already open, it’s best to store it in a refrigerator between 2°C and 8°C. However, you can store it outside the fridge for up to six weeks from opening as long as the temperature does not go above 30°C. Similar to Mounjaro, in line with the hot weather this weekend, you should refrigerate your Wegovy medication,” she added.
Heatwave Forecast and Risks
The Met Office has predicted warmer and drier conditions, with Deputy Chief Meteorologist Steven Keates stating: “From this weekend, the UK forecast will have a distinctly warmer and drier component with a prolonged spell of above-average temperatures. Values in some locations quite likely to reach 27°C to 29°C, with the potential for higher values than this.” This spell is expected to last well into the following week.
Dr Basford also highlighted another major issue masked by the heat: dehydration. Because GLP-1s like Mounjaro or Wegovy suppress appetite, they can also “blur your thirst response,” meaning users may not realise how thirsty they are. She advised: “During a heatwave, your body loses more water than usual through sweating, meaning it’s even easier to become dehydrated. Keep on top of your water intake, aiming for around three litres, staggered throughout the day. A good way to do this is to keep a water intake diary, or purchase a bottle with daily intake targets visible.”
