Mounjaro (tirzepatide) is a dual GIP/GLP-1 receptor agonist licensed in the UK for type 2 diabetes and weight management. Whilst gastrointestinal side effects are well documented, some patients report experiencing sinus issues during treatment. Sinusitis is not listed as a recognised adverse effect of Mounjaro, and upper respiratory symptoms are extremely common in the general population, often coinciding with medication use without being causally related. This article examines the relationship between Mounjaro and sinus problems, explores symptom recognition and management strategies, and clarifies when medical advice should be sought. Understanding the distinction between medication-related effects and coincidental illness is essential for safe, effective treatment.

What Is Mounjaro and How Does It Work?

Mounjaro (tirzepatide) is a prescription medicine licensed in the UK for the treatment of type 2 diabetes mellitus and, more recently, for weight management in adults with obesity (BMI ≥30 kg/m²) or overweight (BMI ≥27 kg/m²) with weight-related comorbidities, as an adjunct to a reduced-calorie diet and increased physical activity. It belongs to a novel class of medications known as dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists. By activating both GIP and GLP-1 receptors, Mounjaro enhances insulin secretion in response to meals, suppresses glucagon release, slows gastric emptying, and reduces appetite—collectively improving glycaemic control and promoting weight loss.

Administered as a once-weekly subcutaneous injection, Mounjaro is typically initiated at a low dose (2.5 mg) and gradually titrated upwards (to 5 mg, 7.5 mg, 10 mg, 12.5 mg, or 15 mg) at 4-week intervals based on individual response and tolerability. This stepwise approach helps minimise gastrointestinal side effects, which are among the most commonly reported adverse reactions. Clinical trials have demonstrated significant reductions in HbA1c and body weight, making Mounjaro an effective option for patients who have not achieved adequate control with other antidiabetic therapies.

Like all medicines, Mounjaro can cause side effects, although not everyone experiences them. The most frequent adverse effects include nausea, vomiting, diarrhoea, constipation, abdominal pain, and decreased appetite. These gastrointestinal symptoms are usually mild to moderate and tend to diminish over time as the body adjusts to the medication. More serious side effects can include pancreatitis (severe abdominal pain), gallbladder disease (right upper quadrant pain, jaundice), dehydration leading to acute kidney injury, and hypersensitivity reactions. There is an increased risk of hypoglycaemia when used with insulin or sulfonylureas. Tirzepatide may also reduce the effectiveness of oral contraceptives, particularly during initiation and dose increases; additional contraceptive methods are advised for 4 weeks after starting treatment and after each dose escalation. Mounjaro is not recommended during pregnancy or breastfeeding.

Recognising Sinus Symptoms While Taking Mounjaro

Sinus issues—medically termed rhinosinusitis—encompass a range of symptoms affecting the nasal passages and paranasal sinuses. Common manifestations include nasal congestion, facial pain or pressure (particularly around the cheeks, forehead, or eyes), postnasal drip, reduced sense of smell, headache, and sometimes fever if infection is present. These symptoms can arise from viral infections (such as the common cold), bacterial sinusitis, allergic rhinitis, or structural abnormalities of the nasal passages.

Sinusitis is not specifically listed as an adverse effect in the Mounjaro (tirzepatide) Summary of Product Characteristics. However, upper respiratory tract infections and nasopharyngitis have been reported with GLP-1 receptor agonists and dual GIP/GLP-1 receptor agonists, though no established causal link with sinusitis has been identified. It's worth noting that upper respiratory symptoms are extremely common in the general population—particularly during autumn and winter months when viral infections are prevalent—and may coincide with medication use without being caused by it.

It is important to distinguish between true medication-related side effects and coincidental illnesses. If you develop sinus symptoms while taking Mounjaro, consider whether you have been exposed to common triggers such as viral infections, allergens (pollen, dust mites, pet dander), or environmental irritants (cigarette smoke, strong perfumes). Keep a symptom diary noting the timing, severity, and any associated factors. This information can be invaluable when discussing your symptoms with a healthcare professional.

Patient awareness is key: while there is no established causal relationship between Mounjaro and sinus problems, any new or persistent symptoms warrant attention. Do not assume that all symptoms experienced during treatment are necessarily caused by the medication, but equally, do not dismiss them without proper evaluation. If you suspect an adverse reaction to Mounjaro, you can report it through the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk or the Yellow Card app).

Managing Sinus Issues During Mounjaro Treatment

If you develop sinus symptoms while taking Mounjaro, several self-care measures can provide relief and support recovery, particularly if the cause is a viral upper respiratory tract infection or mild allergic rhinitis. These strategies are consistent with NHS and NICE guidance for managing acute rhinosinusitis:

• Nasal irrigation: Use a saline nasal spray or rinse (available over-the-counter) to help clear mucus, reduce congestion, and moisturise nasal passages. This simple intervention can significantly improve comfort and is safe for regular use.

• Adequate hydration: Drinking plenty of fluids helps thin mucus secretions, making them easier to clear and reducing postnasal drip.

• Pain relief: Paracetamol or ibuprofen can alleviate facial pain, headache, and any associated fever. Always follow dosing instructions and check for contraindications, particularly if you have other medical conditions.

• Intranasal corticosteroids: For persistent symptoms or those suggesting allergic rhinitis, over-the-counter nasal steroid sprays may be helpful. Follow package instructions carefully.

• Avoid irritants: Minimise exposure to cigarette smoke, strong perfumes, and other environmental irritants that can exacerbate nasal inflammation.

• Decongestants: Over-the-counter oral or nasal decongestants may provide short-term relief but should be used cautiously, especially if you have high blood pressure, heart disease, or diabetes. Nasal decongestants should not be used for more than 5-7 days to avoid rebound congestion.

Continue taking Mounjaro as prescribed unless specifically advised otherwise by your healthcare provider. There is no evidence to suggest that stopping or altering your Mounjaro dose will resolve sinus symptoms, and discontinuing diabetes or weight management medication without medical guidance can lead to deterioration in glycaemic control or weight regain.

If you have diabetes, monitor your blood glucose more frequently during any illness, as infections can affect glycaemic control. Contact your healthcare team if you notice significant changes in your blood glucose levels.

Most cases of acute sinusitis are viral and resolve without antibiotics. However, if symptoms persist beyond 10 days, worsen significantly after initial improvement, or are accompanied by high fever or severe pain, your GP may consider whether bacterial sinusitis has developed. Antibiotics are not routinely needed but may be prescribed in certain circumstances, often with a delayed prescription approach.

When to Seek Medical Advice About Sinus Problems

While most cases of acute rhinosinusitis resolve spontaneously within 2–3 weeks, certain red flag symptoms warrant prompt medical assessment. Contact your GP or seek urgent medical attention if you experience:

• Severe, persistent, or worsening symptoms despite self-care measures, particularly if lasting more than 10 days

• High fever (above 38.5°C) that does not respond to antipyretics

• Severe facial pain or swelling, especially around the eyes

• Visual disturbances, including double vision, reduced vision, or eye pain—these may indicate orbital complications requiring urgent specialist referral

• Severe headache, neck stiffness, or altered consciousness, which could suggest intracranial complications (rare but serious)

• Recurrent episodes of acute sinusitis (four or more episodes per year with complete resolution between episodes) or symptoms persisting beyond 12 weeks, which may indicate chronic rhinosinusitis requiring ENT assessment

People who are immunocompromised or have significant comorbidities should seek medical advice earlier, as they may be at higher risk of complications.

When consulting your healthcare provider, provide a complete medication history, including your Mounjaro dose and duration of treatment, as well as any other prescription or over-the-counter medicines you are taking. Although there is no established causal relationship between Mounjaro and sinus problems, your doctor will want to rule out any potential medication interactions or rare adverse effects.

Your GP may perform a clinical examination of your nasal passages and sinuses. Imaging such as CT scans is not routinely needed but may be arranged if complications are suspected, features are atypical, or surgical intervention is being considered. Management will be tailored to the underlying cause—whether viral, bacterial, allergic, or structural—and may include antibiotics, nasal corticosteroids, antihistamines, or referral to an ENT specialist.

Do not stop taking Mounjaro without discussing it with your prescribing clinician, as maintaining optimal diabetes control and weight management is essential for your overall health. If you have concerns about any aspect of your treatment, your healthcare team is there to support you and address your questions.

Frequently Asked Questions