Rybelsus (semaglutide) is an oral GLP-1 receptor agonist licensed in the UK for managing type 2 diabetes mellitus in adults. Whilst all medications carry potential side effects, patients sometimes wonder whether Rybelsus might increase their risk of urinary tract infections (UTIs). Understanding the relationship between diabetes medications and infection risk is important for informed treatment decisions. This article examines whether Rybelsus causes UTIs, explores the medication's established side effect profile, and provides guidance on recognising and managing urinary symptoms whilst taking this diabetes treatment.

What Is Rybelsus and How Does It Work?

Rybelsus (semaglutide) is an oral medication licensed in the UK 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 that helps regulate blood sugar levels.

The mechanism of action involves several complementary effects. Rybelsus stimulates insulin secretion from the pancreas when blood glucose levels are elevated, whilst simultaneously suppressing the release of glucagon, a hormone that raises blood sugar. Additionally, it slows gastric emptying, which helps reduce post-meal glucose spikes, and may promote a feeling of fullness that can support weight management—an important consideration for many people with type 2 diabetes.

Rybelsus is typically prescribed when diet and exercise alone are insufficient to control blood glucose. According to NICE guidance (NG28), GLP-1 receptor agonists like Rybelsus may be considered when triple therapy is not effective, tolerated or contraindicated, particularly for patients with a BMI ≥35 kg/m² (or lower in certain ethnic groups) or those with significant weight or cardiovascular concerns.

The recommended starting dose is 3 mg once daily for 30 days, then increased to 7 mg once daily. If needed, after at least 30 days on the 7 mg dose, it may be increased to 14 mg once daily. The tablet should be taken on an empty stomach with up to 120 mL of plain water, at least 30 minutes before food, drink or other oral medicines. Tablets must be swallowed whole and should not be split, crushed or chewed.

Rybelsus is not indicated for type 1 diabetes or diabetic ketoacidosis and is not recommended for use in people under 18 years of age. Clinical trials have demonstrated that Rybelsus has cardiovascular safety, making it a valuable option in contemporary diabetes management.

Common Side Effects of Rybelsus

Like all medications, Rybelsus can cause side effects, though not everyone experiences them. The most frequently reported adverse effects are gastrointestinal in nature, particularly during the initial weeks of treatment as the body adjusts to the medication.

Common gastrointestinal side effects include:

• Nausea – often the most prevalent side effect, typically diminishing over time

• Vomiting and diarrhoea – usually mild to moderate in severity

• Abdominal pain and decreased appetite

• Constipation and dyspepsia (indigestion)

These effects are generally most pronounced when starting treatment or increasing the dose, and often improve as treatment continues. Taking the medication as directed and gradually titrating the dose can help minimise gastrointestinal discomfort.

Other reported side effects include dizziness, fatigue, and headache. Some patients may experience hypoglycaemia (low blood sugar), particularly when Rybelsus is used in combination with insulin or sulphonylureas. When starting or increasing the dose of Rybelsus, a reduction in the dose of insulin or sulphonylurea may need to be considered to reduce hypoglycaemia risk. Symptoms of hypoglycaemia include trembling, sweating, confusion, and palpitations.

More serious but rare side effects include:

• Pancreatitis (inflammation of the pancreas) – if suspected (severe, persistent abdominal pain that may radiate to the back, possibly with vomiting), stop taking Rybelsus and seek urgent medical attention

• Diabetic retinopathy complications – particularly in those with pre-existing retinopathy and rapid improvement in blood glucose control

• Gallbladder disease (cholelithiasis or cholecystitis)

• Acute kidney injury – usually secondary to dehydration from severe gastrointestinal side effects

• Hypersensitivity reactions – including anaphylaxis and angioedema

There have been concerns about thyroid C-cell tumours in animal studies, though the relevance to humans is considered uncertain and low.

Regarding urinary tract infections (UTIs), clinical trials and post-marketing surveillance data show no established causal link between Rybelsus and increased UTI risk. Unlike some other diabetes medications (such as SGLT2 inhibitors, which are associated with genitourinary infections), GLP-1 receptor agonists do not have a known mechanism that would predispose patients to UTIs.

If you experience any concerning side effects, report them to your healthcare provider and consider reporting via the MHRA Yellow Card scheme.

UTI Symptoms to Watch For While Taking Rybelsus

Whilst there is no official evidence linking Rybelsus directly to urinary tract infections, people with diabetes are generally at increased risk of UTIs due to several factors related to their underlying condition. Elevated blood glucose levels can create an environment conducive to bacterial growth, and diabetes may affect immune function and bladder emptying.

Key UTI symptoms to be aware of include:

• Dysuria – a burning or stinging sensation when passing urine

• Urinary frequency – needing to urinate more often than usual

• Urinary urgency – a sudden, compelling need to urinate

• Cloudy, dark, or strong-smelling urine

• Haematuria – blood in the urine (may appear pink or red)

• Lower abdominal or pelvic discomfort

• Feeling generally unwell, with possible low-grade fever

In more severe cases, particularly if the infection ascends to the kidneys (pyelonephritis), symptoms may include high fever, rigours (shaking chills), flank pain (pain in the back or side below the ribs), nausea and vomiting, and general malaise. This constitutes a more serious infection requiring prompt medical attention.

Older adults may present atypically, sometimes with new confusion or agitation as the main symptom. Men, pregnant people, those with catheters, people with immunosuppression, and those with recurrent UTIs should have a lower threshold for seeking clinical assessment.

It is important to note that some symptoms, such as increased urination, may overlap with both diabetes control issues and potential UTI. If you are taking Rybelsus and experience new or worsening urinary symptoms, it is advisable to monitor your blood glucose levels and consider whether these symptoms might indicate either poor glycaemic control or a possible infection. Good diabetes management—including maintaining optimal blood sugar levels, staying well hydrated, and practising good personal hygiene—can help reduce UTI risk regardless of the medications you are taking.

When to Seek Medical Advice About UTI Symptoms

If you develop symptoms suggestive of a urinary tract infection whilst taking Rybelsus, it is important to seek appropriate medical advice in a timely manner. Early treatment of UTIs can prevent complications and more serious infections.

You should contact your GP or healthcare provider if you experience:

• Persistent burning or pain when urinating

• Urinary frequency or urgency that is new or significantly worse

• Visible blood in your urine

• Lower abdominal pain or discomfort

• Symptoms that persist for more than 24–48 hours

Seek urgent medical attention (contact NHS 111 or attend A&E) if you develop:

• High fever (temperature above 38°C) with shaking or chills

• Severe back or flank pain, particularly if accompanied by fever

• Persistent vomiting that prevents you from taking fluids or medications

• Confusion or altered mental state

• Signs of sepsis, including rapid heartbeat, rapid breathing, or feeling extremely unwell

When consulting your healthcare provider, inform them that you are taking Rybelsus and provide details about your diabetes management, including recent blood glucose readings. Your healthcare provider may perform a urine dipstick test and, in certain cases, send a sample for culture. Urine cultures are particularly important for men, pregnant people, those with catheters, people with recurrent UTIs, treatment failures, or those with severe/systemic symptoms.

According to NICE guidance, uncomplicated lower UTIs are usually treated with antibiotics. The duration varies: typically 3 days for non-pregnant women, 7 days for men, and different regimens for pregnancy or pyelonephritis. It is essential to complete the full course as prescribed, even if symptoms improve quickly.

Continue taking Rybelsus as directed unless specifically advised otherwise by your healthcare provider. Monitor your blood glucose levels more frequently during the infection, as illness can affect diabetes control. Maintain good hydration, which helps flush bacteria from the urinary system, but seek medical advice if you're unable to keep fluids down. If you have recurrent UTIs (three or more in a year), discuss this with your GP, as further investigation or preventive strategies may be warranted.

Frequently Asked Questions