UK Mounjaro warning issued ahead of heatwave temperatures

Glasgow Times

19-06-2025

It's estimated that around 1.5 million Brits are now taking weight-loss drugs, with numbers increasing each week.
The last year has seen a huge increase in the number of people taking GLP-1 receptor agonists, some prescribed by the NHS and others by private doctors, with common injectibles including semaglutide (Wegovy and Ozempic), tirzepatide (Mounjaro) and liraglutide (Saxenda).
As the temperatures rise, experts are stressing that users must store weight loss injections in a refrigerator (2-8°C or 36-46°F), especially after starting the course.
Review your ICB's local policy about treating patients with tirzepatide (Mounjaro) for weight management in a primary care setting and visit: https://t.co/03msJjjTU9 pic.twitter.com/tHs6lyJHc4 — We are Primary Care (@PrimaryCareNHS) June 12, 2025
'Weight loss injections can be adversely affected by hot weather, particularly regarding storage and stability," says James O'Loan, obesity specialist and weight loss injection expert at pharmacists Chemist4U.
"Understanding the storage instructions when using any prescribed medication is vital to keep it in optimal condition.
"Although weight loss injections can be stored at room temperature for up to 30 days (some injections are 42 days, so always check with your prescriber or refer to the patient information leaflet), this is only provided the temperature does not exceed 30°C. During hot weather, and to be on the safe side, it is always best to keep your weight loss injections refrigerated if you're able."
Can I take my Mounjaro pen on holiday?
The advice for the UK heatwave is also also worth noting for those heading on holiday or travelling during the warmer weather.
However, if you're flying, remember to pack your injections in your carry-on since the baggage hold on a plane can plummet to below-freezing temperatures.
Finding the right temperature for your pen is important: not too hot or too cold. If you inject after incorrectly storing your pen, it might not be safe for use.
How do I know if my Mounjaro pen is safe to use?
"There are a few important things to consider when checking if your weight loss pen is safe to use," says James.
"Inspect the pen to ensure it is not damaged and the medicine inside is clear, with no particles or cloudiness. The liquid should be colourless or slightly yellow. If you have left your pen unrefrigerated during hot weather and are unsure whether it is still safe to use, always consult your prescriber before injecting.
"Staying hydrated whilst taking weight loss injections is key. Weight loss injections can cause side effects such as nausea, constipation, diarrhoea and dizziness, which, without sufficient fluids, can lead to dehydration.
"We recommend drinking plenty of water throughout the day, even when you're not thirsty. If experiencing diarrhoea or vomiting, try using electrolyte drinks, rehydrate quickly and apply sunscreen whenever you are outdoors. This will help those who suffer from heightened sensitivity to UV rays.'
Do you need to tell your travel insurance you are taking Mounjaro?
Yes. Travel insurance providers are warning that the growing number of Brits turning to these breakthrough drugs for weight management could lose their cover and face huge medical bills abroad if they don't declare their usage when arranging travel insurance.
Many don't want to admit they are taking the weight-loss drugs, or think that if they buy it privately, it doesn't need to be declared.
Niraj Mamtora, director at Forum Insurance, says: 'Weight-loss medications like Ozempic are transforming lives across the UK, but too many travellers don't realise the insurance implications. If you're using these drugs, you must declare both the medication and the condition it's prescribed for.
'Failure to do so is not a minor oversight - it's a serious breach of your travel insurance contract. If you need medical help overseas and haven't declared your medication, your claim can be refused and your policy cancelled. The financial consequences can be severe.'
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What happens if you don't disclose weight-loss jabs on your travel insurance?
'Non-disclosure is a gamble that's simply not worth taking," says Niraj.
"If you don't declare your medication or the underlying condition, your insurer is within their rights to refuse any claim, even if it seems unrelated.
'Many travellers only discover too late that their travel insurance claims are rejected, leaving them without support and facing potentially huge bills.
"With the average medical claim abroad now exceeding £1,700, and costs rising significantly with age, being properly covered is more important than ever.'
Insurance claims related to undeclared conditions or medications can be refused, even if the issue seems unrelated.