Many people taking GLP-1 receptor agonists such as semaglutide (Ozempic, Wegovy) or liraglutide (Victoza, Saxenda) report feeling persistently cold, though this is not listed as an official adverse effect. The most likely explanation relates to metabolic changes induced by these medications. GLP-1 agonists promote weight loss through reduced appetite and caloric intake, which can lower metabolic rate and diminish the body's heat-generating capacity. As subcutaneous fat decreases, cold sensitivity often increases. Whilst mild cold intolerance is commonly reported during treatment, certain symptoms warrant medical review to exclude underlying conditions such as hypothyroidism or anaemia.

Why Do GLP-1 Medications Make You Feel Cold All the Time?

GLP-1 receptor agonists, such as semaglutide (Ozempic for type 2 diabetes; Wegovy for weight management) and liraglutide (Victoza for type 2 diabetes; Saxenda for weight management), are increasingly prescribed medications. Some people report feeling persistently cold whilst taking these medications, although this is not listed as an official adverse effect in the Summary of Product Characteristics (SmPC) for these products.

The most likely explanation relates to the metabolic changes these medications induce. GLP-1 agonists work by mimicking the incretin hormone GLP-1, which enhances insulin secretion, suppresses glucagon release, slows gastric emptying, and reduces appetite. The resulting caloric restriction and weight loss can lead to a reduction in metabolic rate—the body's heat-generating capacity. As fat stores diminish, particularly subcutaneous fat which provides insulation, patients may experience increased cold sensitivity.

Additionally, rapid weight loss itself is associated with adaptive thermogenesis, a physiological response where the body conserves energy by reducing heat production. This mechanism, whilst protective from an evolutionary standpoint, can manifest as persistent feelings of coldness, particularly in the extremities. Some patients also report reduced food intake leading to lower core body temperature throughout the day.

It is important to note that there is no established causal link in human studies between GLP-1 receptor activation and thermoregulation. However, the downstream metabolic consequences—weight loss, reduced caloric intake, and changes in body composition—provide a plausible biological basis for this reported symptom. Other common causes of cold intolerance include anaemia, iron or vitamin B12 deficiency, hypothyroidism, Raynaud's phenomenon, and certain medications. If cold intolerance is severe or accompanied by other symptoms such as fatigue, hair loss, or bradycardia, your GP should assess for these underlying conditions.

Managing Persistent Cold Sensations While Taking GLP-1 Medications

If you are experiencing persistent cold sensations whilst taking GLP-1 medications, several practical strategies may help improve your comfort without compromising treatment efficacy.

Dietary and nutritional considerations are paramount. Ensure you are meeting your minimum caloric requirements, even whilst appetite is suppressed. UK dietary reference values recommend approximately 0.75g of protein per kilogram of body weight daily, though during weight loss, higher intakes (1.0-1.2g/kg/day) may help preserve lean muscle mass. Muscle tissue is metabolically active and contributes to heat generation. Consider consulting a registered dietitian for personalised nutritional guidance that balances weight loss goals with metabolic health.

Layering clothing appropriately can provide immediate relief. Focus on thermal base layers, particularly those made from merino wool or technical fabrics designed to trap body heat. Pay special attention to extremities—hands, feet, and head—where heat loss is most pronounced. Keeping core body temperature stable through appropriate clothing can significantly improve comfort levels throughout the day.

Regular physical activity serves a dual purpose: it generates immediate warmth through muscle contraction and helps maintain metabolic rate during weight loss. The UK Chief Medical Officers recommend at least 150 minutes of moderate-intensity activity weekly. Resistance training is particularly beneficial for preserving muscle mass, which supports long-term metabolic health and thermogenesis.

Environmental adjustments at home and work can also help. The NHS recommends maintaining ambient temperatures of at least 18°C, using hot water bottles or heated blankets when resting, and ensuring adequate hydration with warm beverages throughout the day. Remember that GLP-1 injectable medications can be administered regardless of meal timing, while oral semaglutide (Rybelsus) must be taken on an empty stomach with a small sip of water (≤120ml) at least 30 minutes before eating, drinking or taking other oral medicines.

When to Speak to Your GP About Feeling Cold on GLP-1 Treatment

Whilst mild cold sensitivity is commonly reported during GLP-1 treatment and weight loss, certain symptoms warrant prompt medical review to exclude underlying pathology.

Contact your GP if you experience:

• Severe or worsening cold intolerance that significantly impacts daily activities or quality of life

• Additional symptoms suggestive of hypothyroidism, including unexplained fatigue, constipation, dry skin, hair loss, cognitive slowing, or depressive symptoms

• Persistent low body temperature when measured with a reliable thermometer, especially if accompanied by other concerning symptoms

• Cardiovascular symptoms such as unusually slow heart rate (bradycardia), dizziness, or fainting episodes

• Signs of inadequate nutrition, including muscle weakness, difficulty concentrating, or unintentional weight loss exceeding recommended rates (typically >1kg per week)

Your GP may arrange blood tests to assess thyroid function (TSH, free T4), full blood count (to exclude anaemia), iron studies (ferritin), vitamin B12/folate levels, and kidney function (U&Es) as clinically indicated. Caloric restriction during weight loss can temporarily affect thyroid hormone levels, which may contribute to cold sensitivity without representing true hypothyroidism.

Seek urgent same-day medical attention if you develop severe, persistent abdominal pain (especially if radiating to the back), as this could indicate acute pancreatitis, a rare but serious complication of GLP-1 therapy.

It is also important to discuss whether the cold sensitivity is affecting your adherence to treatment or causing significant distress. Your healthcare team can review your overall response to GLP-1 therapy, assess whether dose adjustment might be appropriate, or consider whether the benefits of continuing treatment outweigh the impact on quality of life. Never discontinue prescribed medication without medical guidance, as abrupt cessation may lead to deterioration in glycaemic control or weight regain. A collaborative approach with your GP or diabetes specialist nurse ensures that any adjustments to your treatment plan are made safely and appropriately.

Other Side Effects of GLP-1 Medications You Should Know About

GLP-1 receptor agonists are generally well-tolerated, but patients should be aware of both common and serious adverse effects to ensure safe and effective treatment.

Gastrointestinal side effects are the most frequently reported and include nausea, vomiting, diarrhoea, constipation, and abdominal discomfort. These symptoms typically occur during treatment initiation or dose escalation and often improve over several weeks as the body adapts. Follow the product SmPC titration schedule to minimise these effects. Eating smaller, more frequent meals may also help. Note that injectable GLP-1 medications can be administered regardless of meals, while oral semaglutide must be taken on an empty stomach. Persistent or severe gastrointestinal symptoms should be reported to your GP.

Hypoglycaemia risk is generally low with GLP-1 agonists when used as monotherapy, as their glucose-lowering effect is glucose-dependent. However, when combined with insulin or sulphonylureas, the risk increases significantly. If you take these combinations, your GP may advise increased blood glucose monitoring and possible dose reduction of insulin or sulphonylureas. Learn to recognise hypoglycaemia symptoms (tremor, sweating, confusion, palpitations) and appropriate management strategies.

Rare but serious adverse effects require immediate action:

• Acute pancreatitis: Seek emergency medical attention if you develop severe, persistent abdominal pain radiating to the back, often accompanied by nausea and vomiting

• Gallbladder disease: Rapid weight loss increases the risk of gallstone formation; seek urgent medical advice for right upper quadrant pain or jaundice

• Diabetic retinopathy complications: Patients with pre-existing retinopathy should have regular ophthalmological monitoring, as rapid glycaemic improvement may temporarily worsen retinal disease

• Renal impairment: Dehydration from gastrointestinal side effects can affect kidney function, particularly in vulnerable patients

Injection site reactions (redness, itching, bruising) are common but usually mild. Rotating injection sites and proper technique can minimise these effects. Your practice nurse can demonstrate correct subcutaneous injection technique.

Report any suspected side effects to your healthcare professional and through the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk), which helps monitor medication safety.

Frequently Asked Questions