Ozempic (semaglutide) is a GLP-1 receptor agonist licensed in the UK for treating type 2 diabetes. As with any medication, patients may wonder about potential side effects, including whether Ozempic causes bladder infections. Understanding the relationship between diabetes medications and urinary tract infections is important for safe and effective treatment. This article examines the evidence linking Ozempic to bladder infections, explores common side effects, and provides guidance on when to seek medical advice whilst taking this medication.

What Is Ozempic and How Does It Work?

Ozempic is the brand name for semaglutide, a prescription medication licensed in the United Kingdom for the treatment of type 2 diabetes mellitus in adults. It belongs to a class of medicines called glucagon-like peptide-1 (GLP-1) receptor agonists, which work by mimicking the action of a naturally occurring hormone in the body that helps regulate blood glucose levels. It's important to note that while Ozempic is licensed specifically for type 2 diabetes, Wegovy is the brand name for semaglutide that is licensed for weight management in the UK.

The medication is administered as a once-weekly subcutaneous injection, typically into the abdomen, thigh, or upper arm. Semaglutide works through several complementary mechanisms to improve glycaemic control. It stimulates insulin secretion from the pancreatic beta cells in a glucose-dependent manner, meaning it only triggers insulin release when blood glucose levels are elevated. This reduces the risk of hypoglycaemia compared to some other diabetes medications. Additionally, Ozempic suppresses the release of glucagon, a hormone that raises blood glucose levels, and slows gastric emptying, which helps to moderate the rise in blood glucose after meals.

Beyond its glucose-lowering effects, Ozempic has been shown to promote weight loss in many patients, which can be particularly beneficial for individuals with type 2 diabetes who are overweight or obese. Ozempic is authorised for use alongside diet and exercise to improve blood sugar control. According to NICE guideline NG28 (Type 2 diabetes in adults: management), GLP-1 receptor agonists may be considered when metformin is contraindicated or not tolerated, or when other treatments have not achieved adequate glycaemic control, particularly in patients with a BMI ≥35 kg/m² (or lower in certain ethnic groups) or when weight loss would provide additional clinical benefit.

Common Side Effects of Ozempic

Like all medications, Ozempic can cause side effects, although not everyone experiences them. The most frequently reported adverse effects are gastrointestinal in nature, reflecting the medication's action on the digestive system. These include nausea, vomiting, diarrhoea, abdominal pain, and constipation. These symptoms are typically most pronounced when starting treatment or increasing the dose, and often diminish over time as the body adjusts to the medication. To minimise gastrointestinal side effects, healthcare professionals usually initiate treatment at a low dose and gradually increase it over several weeks.

Severe or persistent gastrointestinal symptoms can lead to dehydration, which may increase the risk of acute kidney injury. Patients should maintain adequate fluid intake and seek prompt medical advice if unable to keep fluids down or experiencing persistent vomiting or diarrhoea.

Other common side effects include injection site reactions such as redness, itching, or swelling at the site where the medication is administered. Some patients may experience fatigue, dizziness, or headaches, particularly during the initial weeks of treatment. Hypoglycaemia, whilst less common with GLP-1 receptor agonists used alone, can occur when Ozempic is combined with other glucose-lowering medications such as sulphonylureas or insulin. Patients taking these combinations should be aware of the signs of low blood sugar, including trembling, sweating, confusion, and palpitations.

Gallbladder problems, including gallstones (cholelithiasis) and inflammation of the gallbladder (cholecystitis), have been reported with semaglutide use. Symptoms may include right upper abdominal pain, fever, nausea, vomiting, or jaundice, and require prompt medical assessment.

More serious but rare adverse effects include pancreatitis, which presents with severe abdominal pain that may radiate to the back. Changes in vision related to diabetic retinopathy may occur, particularly in patients with pre-existing retinopathy and those experiencing rapid improvements in blood glucose control. The MHRA advises appropriate monitoring, especially for patients with a history of diabetic retinopathy, and any concerning symptoms should be reported promptly to a healthcare professional. The benefits of improved glycaemic control typically outweigh the risks for most patients when the medication is used appropriately under medical supervision.

Urinary Tract Infections and Diabetes Medications

Concerns about urinary tract infections, including bladder infections (cystitis), have been raised in relation to certain diabetes medications, particularly sodium-glucose co-transporter-2 (SGLT2) inhibitors such as dapagliflozin and empagliflozin. These medications work by increasing glucose excretion in the urine, which can create an environment more conducive to bacterial growth. While SGLT2 inhibitors are associated with a modestly increased risk of urinary tract infections in some patients, genital mycotic infections (thrush) are actually the more characteristic and common infection risk with this class of medications.

In contrast, there is no established clinical link between GLP-1 receptor agonists like Ozempic and an increased risk of urinary tract or bladder infections. According to the Summary of Product Characteristics for Ozempic approved by the MHRA and the European Medicines Agency's European Public Assessment Report (EPAR), urinary tract infections are not listed as a known side effect of semaglutide. The mechanism of action of semaglutide does not involve altering glucose levels in the urine, which is the primary reason SGLT2 inhibitors may increase infection risk.

That said, people with diabetes in general have a higher baseline risk of developing urinary tract infections compared to the non-diabetic population. This increased susceptibility is related to several factors, including impaired immune function associated with poorly controlled blood glucose, incomplete bladder emptying due to diabetic autonomic neuropathy, and the presence of glucose in the urine when blood sugar levels are elevated. Therefore, whilst Ozempic itself does not appear to cause bladder infections, patients with diabetes should remain vigilant about urinary symptoms regardless of which medications they are taking. Maintaining good glycaemic control, staying well hydrated, and practising good personal hygiene can help reduce the risk of urinary tract infections in people with diabetes, as advised by NICE guidance on urinary tract infections (NG109).

When to Seek Medical Advice While Taking Ozempic

Patients taking Ozempic should be aware of situations that warrant prompt medical attention. If you develop symptoms suggestive of a urinary tract infection—such as burning or pain when passing urine, increased urinary frequency, urgency, cloudy or foul-smelling urine, lower abdominal discomfort, or blood in the urine—you should contact your GP. Whilst these symptoms are not directly caused by Ozempic, they require appropriate investigation and treatment, typically with antibiotics if a bacterial infection is confirmed. If you develop symptoms of pyelonephritis (kidney infection) such as fever, back pain, and feeling generally unwell, contact your GP for same-day assessment or call NHS 111 if your GP is unavailable.

Severe or persistent gastrointestinal symptoms whilst taking Ozempic should also prompt medical review. If you experience severe abdominal pain, particularly if it radiates to your back and is accompanied by nausea and vomiting, this could indicate pancreatitis and requires immediate medical attention via your GP, NHS 111, or 999 in severe cases. Persistent vomiting or diarrhoea can lead to dehydration and potential kidney problems, which is particularly concerning for people with diabetes, and may necessitate temporary adjustment of your diabetes medications.

If you develop symptoms suggestive of gallbladder problems—such as severe pain in the upper right abdomen, fever, nausea, vomiting, or yellowing of the skin or eyes (jaundice)—seek urgent medical advice from your GP or NHS 111.

Signs of hypoglycaemia, especially if recurrent or severe, should be discussed with your diabetes care team, as your treatment regimen may need adjustment. Any sudden changes in vision, symptoms of allergic reaction such as rash, swelling of the face or throat, or difficulty breathing require urgent medical assessment.

Diabetic ketoacidosis (DKA)—with symptoms including excessive thirst, frequent urination, nausea, vomiting, abdominal pain, confusion, or fruity-smelling breath—requires emergency medical attention via 999. While DKA is uncommon in type 2 diabetes and not a direct effect of GLP-1 receptor agonists like Ozempic, it can occur in certain situations, particularly if you are also taking SGLT2 inhibitors or insulin. Regular follow-up with your diabetes care team is essential to monitor your response to Ozempic, adjust dosing as needed, and address any concerns about side effects or symptoms that may arise during treatment.

Frequently Asked Questions