Does Victoza make you sleepy? Victoza (liraglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for treating type 2 diabetes mellitus. Whilst somnolence is not listed as a common adverse reaction in the Medicines and Healthcare products Regulatory Agency (MHRA)-approved Summary of Product Characteristics, fatigue and tiredness are recognised side effects. Some patients report feeling tired during treatment, which may relate to blood glucose fluctuations, dietary changes, gastrointestinal symptoms, or the body's adaptation to improved glycaemic control. Understanding these potential causes helps patients and healthcare professionals manage symptoms effectively whilst maintaining treatment adherence.
Quick Answer: Victoza (liraglutide) does not typically cause sleepiness, though fatigue and tiredness are recognised adverse reactions that may occur due to blood glucose changes, reduced caloric intake, or gastrointestinal side effects.
Victoza (liraglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for the treatment of type 2 diabetes mellitus. Many patients wonder whether this medication can cause sleepiness or fatigue as a side effect. According to the Summary of Product Characteristics (SmPC) approved by the Medicines and Healthcare products Regulatory Agency (MHRA), somnolence or drowsiness is not specifically listed as a common adverse reaction to Victoza, though fatigue and tiredness are recognised adverse reactions.
Some patients do report feeling tired whilst taking this medication. The fatigue that individuals experience may be related to various factors, including changes in blood glucose levels, dietary adjustments, or the body's adaptation to the medication. Type 2 diabetes itself can cause tiredness, and distinguishing between disease-related symptoms and medication effects can be challenging.
Victoza works by mimicking the action of the naturally occurring hormone GLP-1, which stimulates insulin secretion in a glucose-dependent manner, suppresses glucagon release, and slows gastric emptying. While GLP-1 receptor agonists do have central effects (particularly on appetite regulation), they are not typically associated with sedation. Understanding how Victoza functions can help patients and healthcare professionals contextualise any symptoms of tiredness and determine their likely cause, ensuring appropriate management and continued treatment adherence.
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Start HereThe most frequently reported adverse effects of Victoza in clinical trials and post-marketing surveillance involve the gastrointestinal system. Nausea is the most common side effect, affecting more than 1 in 10 patients (very common), particularly during the initial weeks of treatment. This typically improves as the body adjusts to the medication. Other common gastrointestinal effects include:
Diarrhoea – affecting approximately 1 in 10 patients (common)
Vomiting – particularly during dose escalation (common)
Constipation – less common but still reported (common)
Dyspepsia (indigestion or upper abdominal discomfort) (common)
Abdominal pain – usually mild to moderate (common)
Victoza can also cause hypoglycaemia (low blood sugar), especially when used in combination with other glucose-lowering medications such as sulphonylureas or insulin. Symptoms of hypoglycaemia include trembling, sweating, confusion, palpitations, and indeed fatigue or tiredness. It is crucial that patients recognise these symptoms and understand how to manage them appropriately.
Other reported side effects include headache, dizziness, and injection site reactions such as redness, itching, or bruising. Decreased appetite is also common, which is part of the medication's therapeutic effect but may contribute to feelings of low energy if caloric intake becomes insufficient.
Uncommon but serious adverse effects include acute pancreatitis (inflammation of the pancreas), which requires immediate medical attention if severe abdominal pain develops. Gallbladder disorders, including cholelithiasis (gallstones) and cholecystitis, can also occur and may present with right upper quadrant pain, fever, or jaundice.
The MHRA and the European Medicines Agency (EMA) continue to monitor the safety profile of Victoza. Healthcare professionals and patients should report any suspected adverse reactions through the Yellow Card Scheme (yellowcard.mhra.gov.uk).
Although somnolence is not a recognised direct side effect of Victoza, several mechanisms may explain why some patients experience fatigue during treatment. Understanding these potential causes can help patients and clinicians address the issue effectively.
Blood glucose fluctuations represent a possible explanation. Victoza improves glycaemic control by lowering blood glucose levels, and if levels drop too much (hypoglycaemia), tiredness is a common symptom. This risk is particularly increased when Victoza is used alongside sulphonylureas or insulin. Even without frank hypoglycaemia, the transition from chronically elevated glucose levels to better-controlled levels can temporarily affect energy levels as the body adjusts. Patients who have lived with poorly controlled diabetes may initially feel fatigued as their metabolism adapts to more physiological glucose concentrations.
Reduced caloric intake is another contributing factor. Victoza reduces appetite and slows gastric emptying, which helps with weight loss but may lead to insufficient energy intake if patients do not maintain adequate nutrition. This is particularly relevant for individuals who significantly reduce their food consumption without ensuring balanced meals.
Gastrointestinal side effects such as nausea, vomiting, or diarrhoea can indirectly cause fatigue through dehydration, electrolyte imbalances, or general malaise. These symptoms are most pronounced during the initial treatment phase and typically improve over time. Severe gastrointestinal symptoms may lead to dehydration and potentially affect kidney function.
Additionally, underlying diabetes complications or comorbidities may contribute to tiredness. Conditions such as anaemia, thyroid dysfunction, sleep apnoea, depression, or diabetic kidney disease are more common in people with type 2 diabetes and can all cause fatigue. It is essential to consider these possibilities rather than automatically attributing tiredness to Victoza. A comprehensive clinical assessment can help identify the true cause and guide appropriate management.
If you experience fatigue whilst taking Victoza, several practical strategies can help manage this symptom whilst continuing to benefit from the medication's glucose-lowering effects.
Monitor your blood glucose levels regularly, particularly if you feel tired or unwell. Keep a record of your readings and note any patterns. If you experience symptoms of hypoglycaemia (blood glucose typically below 4 mmol/L), take 15–20g of fast-acting carbohydrate (such as glucose tablets, fruit juice, or sugary sweets), wait 10–15 minutes, and recheck your glucose. If levels remain low, repeat the process. Once your blood glucose has recovered, take a longer-acting carbohydrate snack (such as a sandwich or biscuits) to prevent recurrence. Discuss any recurrent hypoglycaemic episodes with your GP or diabetes specialist nurse, as your medication regimen may need adjustment, particularly if you are also taking sulphonylureas or insulin.
Maintain adequate nutrition despite reduced appetite. Focus on:
Regular, balanced meals containing complex carbohydrates, lean protein, and healthy fats
Smaller, more frequent meals if large portions cause nausea
Adequate hydration – aim for 6–8 glasses of water daily
Nutrient-dense foods to ensure sufficient vitamin and mineral intake
Optimise your injection timing. According to the Victoza SmPC, the medication can be administered once daily at any time, independent of meals. However, it should be taken at approximately the same time each day. Some patients find that administering Victoza at a consistent time, such as before breakfast or before bed, helps minimise side effects. Discuss with your healthcare team whether adjusting your injection schedule might help.
Gradual dose escalation is standard practice with Victoza, starting at 0.6 mg daily for at least one week before increasing to 1.2 mg, with a possible further increase to 1.8 mg. This approach helps minimise side effects. Never adjust your dose without medical guidance.
Address lifestyle factors that contribute to fatigue, including ensuring adequate sleep (7–9 hours nightly), regular physical activity appropriate to your fitness level, and stress management. Exercise, even gentle walking, can improve energy levels and glycaemic control.
Whilst mild tiredness may not require immediate medical attention, certain symptoms warrant prompt consultation with your GP, diabetes specialist nurse, or hospital services.
Seek urgent medical advice (contact your GP or NHS 111) if you experience:
Persistent or severe fatigue that interferes with daily activities or does not improve after the initial adjustment period
Recurrent hypoglycaemia – multiple episodes of low blood sugar, particularly if you are not taking sulphonylureas or insulin alongside Victoza
Severe gastrointestinal symptoms – persistent vomiting, severe diarrhoea, or inability to maintain adequate fluid intake, which may lead to dehydration
Signs of dehydration – dark urine, dizziness on standing, dry mouth, or reduced urination
Right upper abdominal pain, fever or jaundice – these could indicate gallbladder problems, which are associated with Victoza use
Neck lump, persistent hoarseness, difficulty swallowing – these symptoms require urgent GP assessment, although the human relevance of thyroid C-cell tumours seen in animal studies remains uncertain according to the EU SmPC
Seek emergency medical attention (call 999 or attend A&E) if you develop:
Severe, persistent abdominal pain that may radiate to the back – this could indicate pancreatitis, an uncommon but serious complication
Symptoms of severe hypoglycaemia – confusion, loss of consciousness, seizures, or inability to self-treat
Allergic reactions – difficulty breathing, swelling of the face or throat, or severe skin reactions
For routine concerns, book an appointment with your GP or diabetes care team to discuss:
Persistent tiredness lasting beyond the first few weeks of treatment
Any new or worsening symptoms
Concerns about medication effectiveness or tolerability
The need for medication review or dose adjustment
NICE guidelines recommend regular monitoring of patients on GLP-1 receptor agonists, including assessment of glycaemic control, weight, and tolerability. Your healthcare team can provide personalised advice and ensure that Victoza remains the most appropriate treatment option for your individual circumstances.
Drowsiness is not listed as a common side effect in the MHRA-approved product information, though fatigue and tiredness are recognised adverse reactions. Most patients do not experience significant sleepiness with Victoza.
Victoza can cause hypoglycaemia (low blood sugar), particularly when combined with sulphonylureas or insulin, and tiredness is a common symptom of low blood glucose. Regular monitoring helps identify and manage this risk.
Contact your GP if you experience persistent or severe fatigue interfering with daily activities, recurrent hypoglycaemia, severe gastrointestinal symptoms, signs of dehydration, or any new concerning symptoms that do not improve after the initial adjustment period.
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