An expert has warned of a ‘significant risk’
08:25, 07 Jan 2026Updated 08:46, 08 Jan 2026
A woman with a weight-loss injection(Image: )
Experts have issued a warning to users of weight-loss injections like Mounjaro as the UK braces for even colder weather – with the Met Office saying some will see up to 20cm of snow. Jason Murphy, weight loss expert at Chemist4U, warned that cold weather can make weight-loss jabs dangerous to use.
He said: “Colder weather can pose a significant risk to those taking weight loss injections, as this can negatively affect storage conditions. Your medication can be significantly affected when temperatures are not correctly maintained. Understanding the storage instructions when using any prescribed medication is vital to keep it in optimal condition.
“Weight loss injections are protein-based biological medications. These are drugs derived from living organisms, such as bacteria, mammalian cells, or yeast. They are complex, large molecules and are produced through biotechnology, making them sensitive to temperature variations and extreme highs and lows. Extremely cold temperatures or freezing can damage their protein structure, harming their medicinal effect, and making them potentially dangerous to use.
“This is because freezing damages the medication at a molecular level, as the active ingredients within weight loss injections are delicate peptide molecules with complex three-dimensional structures that are inherently sensitive to temperature extremes. Freezing causes the formation of ice crystals within the liquid, and these crystals disrupt and rupture the peptide structures. Therefore, if you think your weight loss jab is or has been frozen, dispose of it immediately, as defrosting won’t help to rectify the irreversible structural damage, and the altered molecules will no longer bind effectively to the body’s GLP-1 receptors, significantly reducing or eliminating the medication’s effectiveness.
“It is vital to store weight loss injections in a refrigerator (2-8°C or 36-46°F) to ensure they stay in the best condition. Bear in mind that weight loss injections can be stored at room temperature for up to 30 days (some injections, such as Wegovy, are 42 days, so always check with your prescriber or refer to the patient information leaflet).”
Ice warnings for much of UK
Ice warnings are in place across the UK ahead of a storm which is set to bring heavy snow later in the week. The Met Office has issued yellow ice warnings for most of the UK, including Northern Ireland, for Wednesday morning amid an Arctic air mass which has brought wintry showers across the country.
A yellow warning for snow and ice is in place all day on Wednesday in northern Scotland, with residents there told to expect a further 5-10cm of snow. Temperatures are expected to drop as low as minus 6C in parts of rural Scotland and just below freezing more widely overnight, the Met Office said.
On Tuesday, the temperature at Marham in Norfolk dropped to minus 12.5C, according to the Met Office. It comes before a yellow weather warning for snow, expected in a large part of England covering Sheffield, Peterborough, Bath and Worcester, and in much of Wales, will be in place from 6pm on Thursday until midday Friday.
The severe wintry weather will be brought by the strong winds over northern France, named Storm Goretti by the country’s forecaster, Meteo France. Snow is likely to develop over higher ground in south Wales late on Thursday, before rain turns to snow more widely across England and Wales overnight, the Met Office said.
Some areas could see 5-10cm of snow settle, while others could see as much as 20cm. Storm Goretti is also expected to bring disruption in south-west England, with a yellow warning for strong winds in place for Cornwall, Devon and the Isles of Scilly from 3pm on Thursday until just before midnight.
The UK Health Security Agency (UKHSA) has extended amber cold health alerts for England as an early warning that adverse temperatures are likely to affect health and wellbeing, running until Sunday.