Weight-loss jabs are hailed as the ultimate miracle drug, but doctors are now sounding the alarm on the perils of taking them during the summer.
In fact, the seasonally hot weather might be one of the biggest dangers yet facing users.
GLP-1 medications – originally designed to treat type 2 diabetes and sold under brand names such as Ozempic, Mounjaro and Wegovy – have been widely adopted as blockbuster weight-loss tools.
One in eight adults now say they are taking the medications, a November poll by KFF found.
But like all medicines, they come with their side effects and risks.
Doctors sound the alarm on the dangers facing GLP-1 agonist users this summer (stock image)
Serena Williams and Meghan Trainor, who have each publicly said they had taken the popular weight-loss drugs
As people well know, weight-loss jabs have been linked to a host of serious complications including sight loss, hair loss, scurvy, osteoporosis, sagging skin and even a potentially higher risk of developing pancreatitis – not to mention the serious tummy troubles, like vomiting and diarrhea, that afflict many.
Over in skinny-obsessed Hollywood, a slew of famous figures have recently sparked concern with their alarmingly thin frames. Actresses Demi Moore and Nicole Kidman, alongside reality star Kelly Osbourne and singer Meghan Trainor are all among those accused of taking things too far.
And now, there’s yet another factor people need to watch out for: summer sun.
According to New York City-based Dr Thomas Tsang, things can go downhill fast for GLP-1 users in the hot weather.
‘When the summer heat hits, people taking GLP-1s must be vigilant about how these drugs interact with high temperatures and make small changes to habits to help stay safe,’ Tsang, Chief Medical Officer at Omada Health, told the Daily Mail.
‘GLP-1s slow gastric emptying and suppress appetite, which also inherently blunts your body’s natural thirst signals.
‘In extreme heat, this creates a perfect storm for rapid dehydration – which can amplify common GLP-1 side effects like nausea, dizziness, fatigue and headaches – and, in some cases, can escalate to dangerous kidney strain.’
Boxes of two brand name GLP-1 agonists, Ozempic and Mounjaro, which were delveloped to treat type 2 diabetes but have become known for helping people lose weight
Demi Moore at an event during the 2026 Cannes Film Festival. She has sparked serious concern over her weight loss
With that in mind, thankfully there are some changes patients can make in order to stay on top of these potential side summer effects.
Florida-based bariatric surgeon Dr Wiljon Beltre tells us that he recommends his GLP-1 patients keep a water bottle on them at all times, and that they should be having at least a few sips of water every hour.
‘You should also add a sugar free electrolyte powder to at least one bottle each day, because when you sweat you lose essential minerals like sodium and potassium,’ Beltre told the Daily Mail.
‘If you only drink plain water while eating tiny portions of food, you can dilute your body’s remaining minerals and end up very fatigued.’
Tsang told the Daily Mail that the mineral magnesium is also lost while perspiring, and that a lack of electrolytes as you rehydrate can lead to muscle cramps and brain fog. The proper use of over-the-counter vitamins and supplements may be used to rectify this.
‘Your doctor can help you customize your daily fluid and mineral targets, manage digestion-related nausea, and ensure your lifestyle habits are in sync with your medication,’ Tsang said, noting the importance of seeking medical advice first.
But hydration isn’t the only thing those on weight loss jabs will need to monitor.
Tsang said patients should pay attention to the color of their urine, ensuring it remains ‘pale and clear.’
Doctors tell the Daily Mail that the summer heat can cause serious health problems for GLP-1 patients (stock image)
Kardashian family member Scott Disick has confessed to taking Mounjaro
The most important thing to look out for this summer are signs of heat stress, which can turn into life-threatening heat stroke.
‘If you begin to experience warning signs like a racing heart, sudden lightheadedness, throbbing headaches, muscle weakness or severe nausea, you should stop what you are doing immediately,’ Tsang said. ‘These are red flags that your body is struggling to cool down.
‘Your first step is to seek a cool, shaded or air-conditioned space, sit down and apply cool, damp cloths to your skin.
‘You should also slowly sip water or an electrolyte solution, keeping in mind that since GLPs slow how quickly your stomach empties, chugging fluids too fast could trigger vomiting.’
Tsang warned that heat stress has the potential to escalate into heat exhaustion or heat stroke, which can ‘pose a severe risk of acute kidney strain.’
‘You should make sure to mention that you take a GLP-1 if you need to seek medical attention,’ he advised.
In addition to paying attention to your body’s reaction in the heat, it’s also important to monitor the temperature of your actual medication.
Beltre warned that if weight loss drugs – some of which have to be stored in a fridge – get too hot, they have the potential to stop working.
‘You also need to watch the actual medication pens, because if you leave them in a hot car or beach bag where the temp gets above 86 degrees (F), the liquid can degrade and stop working,’ he said.
