Does Saxenda make your urine smell? Saxenda (liraglutide), a GLP-1 receptor agonist licensed for weight management in the UK, is not directly known to cause changes in urine odour. This effect is not listed in the Summary of Product Characteristics or Patient Information Leaflet. However, some patients report noticing alterations in urine smell during treatment. These changes are typically related to the weight loss process itself—including dietary modifications, dehydration from gastrointestinal side effects, or mild ketosis—rather than a direct pharmacological effect of the medication. Understanding these indirect mechanisms helps patients recognise when changes are benign and when medical review is warranted.

Does Saxenda Make Your Urine Smell?

Saxenda (liraglutide) is not directly known to cause changes in urine odour as a recognised side effect. This is not listed in the UK Summary of Product Characteristics (SmPC) or Patient Information Leaflet (PIL). While some individuals using Saxenda for weight management have anecdotally reported noticing alterations in their urine smell during treatment, there is no official link established between Saxenda itself and urine odour changes.

Saxenda is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for weight management in adults with a body mass index (BMI) of 30 kg/m² or greater, or 27 kg/m² or greater in the presence of weight-related comorbidities such as prediabetes/type 2 diabetes, hypertension, dyslipidaemia or obstructive sleep apnoea. The medication works by mimicking the action of the naturally occurring hormone GLP-1, which regulates appetite and food intake by acting on receptors in the brain, pancreas, and gastrointestinal tract. This leads to reduced hunger, increased feelings of fullness, and slower gastric emptying.

Whilst Saxenda does not chemically alter urine composition in a way that would directly cause odour changes, the weight loss process itself and associated metabolic changes may be responsible for any perceived differences in urine smell. If you notice persistent or concerning changes in your urine whilst taking Saxenda, it is advisable to discuss these observations with your GP or prescribing clinician to rule out other potential causes.

Why Might Urine Smell Change During Saxenda Treatment?

Several factors related to weight loss and dietary changes during Saxenda treatment may contribute to alterations in urine odour, even though the medication itself does not directly cause this effect.

Dietary modifications are a cornerstone of successful weight management with Saxenda. Many patients significantly reduce their carbohydrate intake or adopt lower-calorie eating patterns, which can influence the concentration and composition of urine. When fluid intake does not keep pace with reduced food consumption, urine may become more concentrated, leading to a stronger, more noticeable odour. Additionally, certain foods—such as asparagus, coffee, or foods high in sulphur compounds—can impart distinctive smells to urine, and these may become more apparent during periods of dietary change.

Dehydration is another important consideration. According to the Saxenda SmPC, gastrointestinal side effects are common, particularly during the initial titration phase, including nausea, vomiting, and diarrhoea. These symptoms can lead to reduced fluid intake or increased fluid loss, resulting in concentrated urine with a more pungent odour. The NHS recommends aiming for 6-8 drinks per day to maintain adequate hydration, which is particularly important if you experience these side effects.

Metabolic changes associated with weight loss can also play a role. As the body begins to utilise fat stores for energy—a process that occurs during caloric restriction—various metabolic by-products are produced and excreted through urine. These compounds may contribute to changes in urine smell, particularly if weight loss is rapid or substantial. Understanding these indirect mechanisms helps patients recognise that urine odour changes are more likely related to the weight loss process rather than a direct pharmacological effect of Saxenda.

Ketosis and Weight Loss: Understanding the Connection

One of the most common explanations for changes in urine odour during weight loss is ketosis—a metabolic state in which the body primarily burns fat for fuel rather than carbohydrates. When carbohydrate intake is significantly reduced or caloric restriction is substantial, the liver converts fatty acids into ketone bodies (acetoacetate, beta-hydroxybutyrate, and acetone) to provide energy for the brain and other tissues.

Ketone bodies are excreted through urine and breath, and they possess a characteristic sweet or fruity odour that many people describe as unusual or strong. Acetone, one of the ketone bodies, is particularly volatile and contributes to the distinctive smell associated with ketosis. This is the same metabolic process that occurs during very low-carbohydrate diets, prolonged fasting, or inadequate caloric intake.

Whilst Saxenda does not directly induce ketosis through its mechanism of action, the reduced caloric intake and appetite suppression it facilitates may lead some patients into a mild ketotic state, particularly if carbohydrate consumption is low. This is generally considered a normal physiological response to weight loss and is not inherently harmful in individuals without diabetes.

Patients with type 2 diabetes should be particularly vigilant. The MHRA Drug Safety Update (2019) has highlighted rare reports of diabetic ketoacidosis (DKA) in patients treated with GLP-1 receptor agonists, particularly when insulin is rapidly reduced or discontinued. Patients with diabetes should not adjust their insulin without medical supervision. According to NHS guidance, symptoms of DKA include excessive thirst, frequent urination, nausea, vomiting, abdominal pain, confusion, or unusual fatigue. If these symptoms occur, seek immediate medical attention by calling 999 or attending A&E. For most patients without diabetes, mild ketosis during weight loss is a normal finding, but maintaining a balanced diet with adequate nutrition remains important for overall health and sustainable weight management.

When to Seek Medical Advice About Urine Changes

Whilst changes in urine odour during Saxenda treatment are often benign and related to dietary changes or mild ketosis, certain signs and symptoms warrant prompt medical evaluation. Patients should contact their GP or healthcare provider if they experience:

• Dark or concentrated urine accompanied by reduced urine output, which may indicate dehydration requiring intervention

• Foul-smelling urine with dysuria (painful urination), frequency, urgency, or suprapubic pain, which may suggest a urinary tract infection

• Sweet or fruity-smelling urine combined with excessive thirst, frequent urination, nausea, vomiting, or abdominal pain—particularly in patients with diabetes, as these may indicate diabetic ketoacidosis requiring emergency care (call 999 or attend A&E)

• Blood in the urine (haematuria) or pain during urination, which requires investigation

• Fever or flank pain with urinary symptoms, which could indicate pyelonephritis (kidney infection)

Urinary tract infections (UTIs) can occur independently of Saxenda treatment. Women are particularly susceptible to UTIs, and any suspected infection should be evaluated promptly with urinalysis and, if appropriate, urine culture.

Additionally, patients should report any severe or persistent gastrointestinal side effects from Saxenda, such as intractable nausea, vomiting, or diarrhoea, as these can lead to dehydration and electrolyte imbalances. According to the Saxenda SmPC, if an increase in dose is not tolerated, consider delaying dose escalation by another week. Treatment should be discontinued if the 3.0 mg dose cannot be tolerated.

For urgent medical concerns that are not emergencies, contact NHS 111 for advice. Regular monitoring as recommended by your prescribing clinician is essential. This typically includes periodic assessment of weight loss progress, tolerability of the medication, and screening for potential complications. Never hesitate to discuss any concerns about bodily changes during treatment—early identification of problems allows for timely intervention and ensures safe, effective use of Saxenda.

Managing Side Effects While Taking Saxenda

Successful management of Saxenda treatment involves not only addressing potential urine odour changes but also implementing strategies to minimise common side effects and optimise weight loss outcomes.

Maintaining adequate hydration is paramount. The NHS recommends aiming for 6-8 drinks per day, though this advice may need to be tailored if you have heart failure or chronic kidney disease. Proper hydration helps dilute urine, reducing concentration-related odour, and supports overall metabolic function. If plain water is unappealing, consider herbal teas or water infused with fruit, but avoid excessive consumption of caffeinated or sugary beverages.

Following the prescribed titration schedule is crucial for minimising gastrointestinal side effects. According to the Saxenda SmPC, treatment is initiated at 0.6 mg daily and gradually increased over several weeks to the maintenance dose of 3.0 mg daily. This stepwise approach allows the body to adapt to the medication. If side effects are troublesome, the SmPC advises that dose escalation may be delayed by an additional week.

Adopting a balanced, nutritious diet supports both weight loss and overall health. Whilst caloric restriction is necessary for weight loss, ensure adequate intake of protein, healthy fats, and complex carbohydrates to prevent excessive ketosis and maintain energy levels. The NHS Eatwell Guide provides evidence-based recommendations for balanced nutrition. Working with a registered dietitian can help tailor dietary strategies to your individual needs and preferences.

Monitoring for common adverse effects allows for early intervention. According to the Saxenda SmPC, the most frequently reported side effects include nausea (occurring in more than 1 in 10 patients), diarrhoea, constipation, vomiting, and headache. These typically diminish over time as the body adjusts to treatment. Saxenda can be injected once daily at any time, independent of meals, but using a consistent time each day may help with adherence.

Regular follow-up with your healthcare provider ensures treatment remains safe and effective. The SmPC states that treatment should be discontinued if less than 5% weight loss is achieved after 12 weeks at the maintenance dose of 3.0 mg. Your clinician will also monitor for potential complications and adjust treatment as needed to support your long-term weight management goals.

If you suspect you are experiencing side effects from Saxenda, report them to the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk or via the Yellow Card app.

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