Will Victoza make you tired? Victoza (liraglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist used to manage type 2 diabetes. Whilst tiredness is not listed amongst the most common side effects in UK regulatory guidance, some patients do report fatigue during treatment. The most frequently documented adverse effects include nausea, diarrhoea and vomiting. However, tiredness may occur indirectly through blood glucose fluctuations, gastrointestinal symptoms, dehydration or the body's adjustment to metabolic changes. Understanding why fatigue might develop and when to seek medical advice can help you manage this symptom effectively whilst continuing your diabetes treatment.

Does Victoza Cause Tiredness or Fatigue?

Victoza (liraglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist prescribed for type 2 diabetes management at doses up to 1.8 mg daily. For weight management, a higher dose of liraglutide (3 mg) is available under the brand name Saxenda, not Victoza. Whilst tiredness is not listed amongst the most common adverse effects in the Summary of Product Characteristics (SmPC) approved by the Medicines and Healthcare products Regulatory Agency (MHRA), some patients do report experiencing fatigue when taking this medication.

The most frequently documented side effects of Victoza include nausea, diarrhoea and vomiting (very common, affecting more than 1 in 10 people) and headache (common, affecting up to 1 in 10 people), particularly during the initial weeks of treatment. Individual responses to medications vary considerably, and fatigue may occur indirectly through several mechanisms related to how Victoza affects your body.

It is important to distinguish between direct drug-related fatigue and tiredness arising from other factors associated with diabetes treatment. Victoza works by enhancing insulin secretion in response to meals, suppressing glucagon release, slowing gastric emptying, and reducing appetite—all of which can influence energy levels and how you feel throughout the day. If you are experiencing persistent tiredness since starting Victoza, this warrants discussion with your healthcare team to identify the underlying cause and determine whether the medication is contributing to your symptoms or whether other factors require investigation.

Why Might You Feel Tired When Taking Victoza?

Several mechanisms may explain why some individuals experience tiredness whilst taking Victoza, even though fatigue is not a recognised common side effect. Understanding these potential causes can help you and your healthcare provider identify the most likely explanation.

Blood glucose fluctuations represent one possible contributor. Victoza enhances glucose-dependent insulin secretion, meaning it helps your pancreas release insulin when blood sugar rises. Whilst the risk of hypoglycaemia (low blood sugar) is relatively low with Victoza monotherapy, it increases when combined with other diabetes medications such as sulphonylureas or insulin. If you are taking these medications alongside Victoza, your doctor may need to reduce their doses to prevent hypoglycaemia. Even mild hypoglycaemia can cause fatigue, weakness, and difficulty concentrating. Conversely, if your diabetes control is improving and blood glucose levels are dropping from previously elevated levels, your body may need time to adjust to this new metabolic state, potentially causing temporary tiredness.

Gastrointestinal side effects are amongst the most common adverse reactions to Victoza. Nausea, diarrhoea and vomiting are very common, particularly during initial treatment. Persistent nausea, reduced appetite, and altered eating patterns can lead to inadequate caloric intake, potentially resulting in fatigue. The medication's effect on gastric emptying—slowing the rate at which food leaves your stomach—may also contribute to feelings of fullness, reduced food intake, and subsequent low energy levels.

Dehydration may occur if gastrointestinal side effects such as vomiting or diarrhoea are present, which can lead to acute kidney injury in severe cases and manifest as tiredness and lethargy. Additionally, some patients experience headaches when starting Victoza, which may be accompanied by general malaise and fatigue. The body's adjustment period to any new medication can also temporarily affect energy levels as physiological systems adapt to the drug's presence and effects.

Managing Fatigue While Using Victoza

If you are experiencing tiredness whilst taking Victoza, several practical strategies may help manage this symptom whilst continuing your diabetes treatment effectively.

Monitor your blood glucose levels regularly, particularly if you are taking Victoza alongside other glucose-lowering medications. Keep a record of your readings and note when you feel most tired to identify any correlation with low blood sugar. Follow the glucose targets agreed in your individual care plan; NICE focuses on individualised HbA1c targets rather than specific capillary glucose ranges. If you are also taking a sulphonylurea or insulin, your prescriber may reduce the dose to lower your hypoglycaemia risk. If you suspect hypoglycaemia, treat it promptly with fast-acting carbohydrates and discuss your medication regimen with your GP or diabetes specialist nurse.

Optimise your nutrition despite potential appetite changes. Even if Victoza reduces your hunger, ensure you consume regular, balanced meals containing adequate protein, complex carbohydrates, and healthy fats to maintain energy levels throughout the day. Small, frequent meals may be better tolerated than larger portions if you experience nausea or early satiety. Stay well-hydrated by drinking plenty of water, particularly if you have experienced any gastrointestinal upset.

Allow time for adjustment. Many side effects of Victoza, including nausea and potential fatigue, often improve after the first few weeks as your body adapts to the medication. The dose is typically titrated gradually—starting at 0.6 mg daily for one week, then increasing to 1.2 mg, with a possible further increase to 1.8 mg—which helps minimise adverse effects.

Maintain good sleep hygiene and ensure you are getting adequate rest. Regular physical activity, as recommended by the UK Chief Medical Officers' guidelines (at least 150 minutes of moderate-intensity activity weekly for adults), can actually help combat fatigue and improve overall energy levels. This should be adjusted according to individual capabilities and any complications.

If you experience severe abdominal pain radiating to your back, stop taking Victoza immediately and seek urgent medical advice, as this could indicate pancreatitis—a rare but serious potential adverse effect of GLP-1 receptor agonists.

When to Seek Medical Advice About Tiredness on Victoza

Whilst mild, temporary tiredness may not require immediate medical attention, certain situations warrant prompt contact with your GP or diabetes care team.

Seek urgent medical advice if you experience:

• Severe or persistent fatigue that significantly impairs your daily activities or quality of life

• Symptoms of hypoglycaemia including shakiness, sweating, confusion, rapid heartbeat, or difficulty concentrating, particularly if these episodes are frequent

• Signs of dehydration such as dark urine, dizziness, dry mouth, or reduced urination, especially if accompanied by vomiting or diarrhoea

• Severe abdominal pain radiating to your back, which could indicate pancreatitis—stop taking Victoza immediately and seek urgent medical help

• Right upper abdominal pain, fever or jaundice (yellowing of skin/eyes), which could indicate gallbladder disease, more common in GLP-1 receptor agonist users

• Unexplained weight loss beyond what would be expected from improved diabetes control

• Mood changes including persistent low mood or depression, as fatigue can sometimes be a symptom of mental health concerns

For severe symptoms, contact NHS 111 for urgent advice or call 999/go to A&E in an emergency.

Contact your healthcare provider for a routine review if tiredness persists beyond the first month of treatment or worsens over time. Your doctor may wish to:

• Review your current medication regimen and consider dose adjustments

• Check your HbA1c and recent blood glucose patterns

• Perform blood tests to exclude other causes of fatigue, such as anaemia, thyroid dysfunction, vitamin B12 deficiency (particularly relevant if you take metformin), or kidney function changes

• Assess for diabetes-related complications that might contribute to fatigue

• Consider whether Victoza remains the most appropriate treatment option for you

Never stop taking Victoza abruptly without medical guidance, as this may lead to deterioration in your diabetes control. Your healthcare team can help determine whether your fatigue is medication-related or requires investigation for alternative causes.

If you suspect your symptoms are a side effect of Victoza, you can report this through the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk).

Alternative Explanations for Fatigue in Diabetes

When experiencing tiredness whilst taking Victoza, it is essential to consider that fatigue is a common symptom in people with diabetes and may have multiple causes unrelated to this specific medication.

Suboptimal diabetes control itself is a frequent cause of fatigue. Both hyperglycaemia (high blood sugar) and hypoglycaemia can cause tiredness. When blood glucose levels are consistently elevated, your cells cannot efficiently utilise glucose for energy, leading to fatigue despite adequate food intake. Conversely, low blood sugar deprives your brain and muscles of their primary fuel source. If you have recently started Victoza, your fatigue might actually reflect pre-existing poor glycaemic control rather than a medication side effect.

Diabetes-related complications can contribute to tiredness. These include:

• Diabetic nephropathy (kidney disease), which can cause anaemia and accumulation of waste products

• Cardiovascular disease, reducing the heart's efficiency in delivering oxygen to tissues

• Diabetic neuropathy (nerve damage), which may disrupt sleep quality

• Sleep apnoea, more common in people with type 2 diabetes and obesity, causing poor sleep quality and daytime fatigue

Concurrent medications should also be considered. Many people with type 2 diabetes take multiple medications for associated conditions such as hypertension, high cholesterol, or depression—some of which list fatigue as a potential side effect. Beta-blockers, for example, commonly cause tiredness.

Lifestyle factors including inadequate sleep, poor diet, physical inactivity, stress, and obesity all contribute to fatigue and are common in people with type 2 diabetes. Nutritional deficiencies, particularly vitamin B12 deficiency (which can be exacerbated by long-term metformin use, as noted in NICE guidance), iron deficiency, or vitamin D deficiency, may cause persistent tiredness.

Other medical conditions such as hypothyroidism, depression, chronic kidney disease, or anaemia are more prevalent in people with diabetes and should be investigated if fatigue persists. A comprehensive assessment by your GP or diabetes team, including appropriate blood tests and review of all medications and lifestyle factors, can help identify the true cause of your tiredness and guide appropriate management.

Frequently Asked Questions