Rybelsus (semaglutide) is an oral GLP-1 receptor agonist licensed in the UK for treating type 2 diabetes mellitus in adults. Whilst the medication is effective at improving blood glucose control and often leads to weight loss, patients may wonder about potential side effects, including sexual dysfunction. Sexual side effects are not listed among the known adverse reactions to Rybelsus in clinical trial data or product information. However, type 2 diabetes itself is strongly associated with sexual difficulties in both men and women. This article examines the evidence around Rybelsus sexual side effects, common adverse reactions, and when to seek medical advice.

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. Rybelsus is typically prescribed when diet and exercise alone have not achieved adequate blood glucose control, and it may be used alongside other diabetes medications such as metformin.

The active ingredient, semaglutide, works by mimicking the action of a naturally occurring hormone called GLP-1. This hormone is released by the gut in response to food intake and plays several important roles in glucose regulation. Rybelsus stimulates insulin secretion from the pancreas when blood glucose levels are elevated, helping to lower blood sugar after meals. It also suppresses the release of glucagon, a hormone that raises blood glucose, and slows gastric emptying, which means food leaves the stomach more gradually. These combined effects help improve glycaemic control throughout the day.

Additionally, many patients taking Rybelsus experience reduced appetite and weight loss, which can be beneficial for individuals with type 2 diabetes who are overweight or obese, although Rybelsus is not licensed specifically for weight management. The medication is taken once daily as a tablet. According to NICE guidance (NG28), GLP-1 receptor agonists like semaglutide are recommended for specific patient groups when other treatments have not been sufficient.

Rybelsus is started at 3 mg once daily for one month, then increased to 7 mg daily, with a possible further increase to 14 mg daily if needed. Tablets must be swallowed whole with up to 120 ml of water on an empty stomach, at least 30 minutes before eating, drinking or taking other oral medicines. Importantly, Rybelsus is not indicated for type 1 diabetes, is not a substitute for insulin, and should not be used alongside other GLP-1 receptor agonists. Women who are pregnant, planning pregnancy or breastfeeding should not take Rybelsus and should discuss alternative diabetes treatments with their healthcare provider.

Common Side Effects of Rybelsus

Like all medications, Rybelsus can cause side effects, although not everyone will experience them. The most frequently reported adverse effects are gastrointestinal in nature and tend to occur particularly during the initial weeks of treatment as the body adjusts to the medication. These include:

• Nausea — very common (may affect more than 1 in 10 people)

• Vomiting and diarrhoea — common (may affect up to 1 in 10 people), especially when starting treatment or increasing the dose

• Abdominal pain and bloating — related to the slowing of gastric emptying

• Reduced appetite — common and may contribute to weight reduction

• Constipation — common according to the product information

These gastrointestinal symptoms are usually mild to moderate and often improve over time as the body adapts to the medication. Starting with a lower dose and gradually increasing it, as prescribed, can help minimise these effects.

Other side effects that may occur include headache, dizziness, fatigue, and hypoglycaemia (low blood sugar), particularly if Rybelsus is taken alongside other glucose-lowering medications such as sulphonylureas or insulin. Patients should be aware of the signs of hypoglycaemia, which include sweating, trembling, confusion, and palpitations.

Less common but important side effects include gallbladder problems (such as gallstones) and a risk of acute kidney injury if severe vomiting or diarrhoea leads to dehydration.

Regarding sexual side effects specifically, these are not listed among the known adverse reactions to semaglutide in the product information or clinical trial data. However, it is important to recognise that type 2 diabetes itself is strongly associated with sexual dysfunction in both men and women, including erectile dysfunction, reduced libido, and difficulties with arousal or satisfaction. Any concerns about sexual health should be discussed openly with a healthcare professional to determine whether symptoms are related to the underlying condition, other medications, or psychological factors rather than Rybelsus itself.

Managing Side Effects While Taking Rybelsus

If you experience side effects while taking Rybelsus, there are several practical strategies that can help you manage them effectively and continue benefiting from the medication.

For gastrointestinal symptoms such as nausea, vomiting, or abdominal discomfort:

• Eat smaller, more frequent meals rather than large portions, which can help reduce nausea and bloating

• Avoid fatty, fried, or spicy foods that may exacerbate stomach upset

• Stay well hydrated, especially if experiencing vomiting or diarrhoea, to prevent dehydration

• Take Rybelsus correctly — always on an empty stomach with no more than 120ml of water, at least 30 minutes before eating, drinking, or taking other medications

• Swallow tablets whole — do not split, crush or chew them as this may affect how the medicine works

• Allow time for adjustment — many gastrointestinal side effects improve within the first few weeks as your body adapts

If you are experiencing hypoglycaemia (low blood sugar), particularly if taking Rybelsus with other diabetes medications, ensure you:

• Carry fast-acting glucose (such as glucose tablets or sugary drinks) with you at all times

• Monitor your blood glucose levels regularly, especially when starting treatment or changing doses

• Discuss dose adjustments of sulphonylureas or insulin with your GP or diabetes specialist if hypoglycaemia becomes frequent

If you miss a dose of Rybelsus, skip the missed dose and take your next dose the following day as usual. Do not take a double dose to make up for a forgotten tablet.

For concerns about sexual function, it is important to consider the broader context. Type 2 diabetes, cardiovascular disease, obesity, and psychological stress all contribute to sexual difficulties. Improving overall diabetes control, maintaining a healthy weight, staying physically active, and managing stress can all have positive effects on sexual health. If you suspect a medication may be contributing to sexual side effects, do not stop taking Rybelsus without medical advice. Instead, arrange a consultation with your GP to review your symptoms and explore potential causes and solutions. Open communication with your healthcare team is essential for optimising both your diabetes management and your overall quality of life.

When to Speak to Your GP About Rybelsus

While many side effects of Rybelsus are mild and self-limiting, there are certain situations where you should contact your GP or healthcare team promptly for advice and possible review of your treatment.

Seek medical attention if you experience:

• Severe or persistent nausea and vomiting that prevents you from eating or drinking adequately, as this may lead to dehydration

• Severe abdominal pain, particularly if it radiates to the back, as this could indicate pancreatitis — a rare but serious side effect of GLP-1 receptor agonists

• Signs of dehydration, such as dark urine, dizziness, dry mouth, or reduced urination

• Frequent hypoglycaemia (low blood sugar episodes), especially if you are also taking sulphonylureas or insulin

• Unexplained weight loss that seems excessive or concerning

• Visual changes or symptoms of diabetic retinopathy worsening, which should be monitored in patients with existing eye complications

• Allergic reactions, such as rash, itching, swelling, or difficulty breathing

• Upper right abdominal pain, fever or yellowing of the skin or eyes, which could indicate gallbladder problems

• Reduced urine output, swelling or confusion, which might suggest acute kidney injury

Call 999 immediately if you experience severe chest pain, a severe allergic reaction (anaphylaxis) with breathing difficulties, or severe sudden abdominal pain with vomiting. For urgent but non-emergency concerns, contact NHS 111 for advice.

Regarding sexual health concerns, if you notice changes in sexual function, libido, or satisfaction after starting Rybelsus, it is important to discuss this openly with your GP. While there is no established causal link between Rybelsus and sexual dysfunction, your doctor can help determine whether your symptoms are related to diabetes itself, other medications (such as antihypertensives or antidepressants), hormonal factors, or psychological issues. Your GP may recommend:

• Reviewing your overall medication regimen to identify any potential contributors

• Optimising diabetes control, as better glucose management often improves sexual function

• Referral to specialist services if appropriate, such as endocrinology, urology, or sexual health clinics

• Addressing cardiovascular risk factors, as vascular health is closely linked to sexual function

If you become pregnant or are planning pregnancy, contact your healthcare team immediately as Rybelsus is not recommended during pregnancy or breastfeeding.

Never stop taking Rybelsus suddenly without consulting your healthcare team, as this may lead to worsening blood glucose control. Your GP can work with you to find the most appropriate treatment plan that balances effective diabetes management with acceptable tolerability and quality of life.

If you suspect you are experiencing a side effect from Rybelsus, you can report it to the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk or via the Yellow Card app.

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