Experts urge GLP-1 users in the UK to monitor hydration as heatwave persists

As the UK continues to experience unusually high temperatures, health professionals are reminding people who use GLP-1 receptor agonists for weight management to pay close attention to their fluid intake. GLP-1 medications, which include drugs such as semaglutide and liraglutide, work in part by slowing digestion and reducing appetite, but these same mechanisms can make users more vulnerable to dehydration in hot weather.

Why the risk increases in hot weather

Because GLP-1 drugs can suppress thirst signals alongside appetite, users may not feel the urge to drink as their bodies lose water through sweat. Common side effects such as nausea, vomiting and diarrhoea can further reduce fluid levels, compounding the problem during a heatwave when the body is already working harder to stay cool.

Recommended precautions

Guidance shared with patients generally focuses on proactive hydration rather than waiting until thirst develops. Practical steps often highlighted by clinicians include:

• Sipping water steadily throughout the day rather than drinking large amounts at once
• Carrying a reusable bottle so fluids are always within reach
• Avoiding alcohol and excessive caffeine, which can add to fluid loss
• Eating water-rich foods such as cucumber, melon and yoghurt to support overall intake

Anyone experiencing persistent dizziness, a dry mouth, reduced urination or unusual fatigue while on a GLP-1 medication during hot weather is generally advised to contact their prescribing clinician. People planning their weekly menus around warmer conditions can also find useful guidance in resources on adopting a Mediterranean-inspired weekly meal schedule and optimizing nutrition through strategic food pairings.

For broader context on how these medications are influencing household behaviour, read about the rising popularity of weight-loss medications and reduced household food spending.