Does Mounjaro cause hot flushes? This is a question some patients taking tirzepatide have raised, particularly when experiencing new or unexplained symptoms during treatment. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist licensed in the UK for type 2 diabetes and, as Zepbound, for weight management. Whilst hot flushes are not listed as a recognised side effect in UK prescribing information, understanding the relationship between this medication and vasomotor symptoms is important for patients and clinicians. This article examines the evidence, explores possible explanations, and provides practical guidance on managing hot flushes whilst taking Mounjaro.

Understanding Mounjaro and Its Common Side Effects

Mounjaro (tirzepatide) is a prescription medication licensed in the UK for the treatment of type 2 diabetes mellitus. In the UK, tirzepatide is also available under the brand name Zepbound for weight management in adults with obesity or overweight with weight-related comorbidities. It belongs to a novel class of medicines known as dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists. By mimicking the action of these naturally occurring incretin hormones, Mounjaro enhances insulin secretion when blood glucose levels are elevated, suppresses glucagon release, slows gastric emptying, and reduces appetite—mechanisms that collectively improve glycaemic control and promote weight loss.

As with all medications, Mounjaro is associated with a range of potential side effects. The most commonly reported adverse effects include gastrointestinal symptoms such as nausea, vomiting, diarrhoea, constipation, abdominal pain, and decreased appetite. These effects are typically mild to moderate in severity and often diminish over time as the body adjusts to the medication. Other recognised side effects include injection site reactions, fatigue, and dyspepsia. Hypoglycaemia may occur, particularly when Mounjaro is used in combination with insulin or sulfonylureas; dose reductions of these medications may be required to reduce this risk.

Important safety warnings include the risk of pancreatitis (seek urgent medical attention for severe, persistent abdominal pain, with or without vomiting), gallbladder disease, and dehydration leading to acute kidney injury with prolonged vomiting or diarrhoea.

It is important for patients and healthcare professionals to be aware of the full spectrum of potential adverse effects to ensure appropriate monitoring and management. The Medicines and Healthcare products Regulatory Agency (MHRA) and the European Medicines Agency (EMA) provide comprehensive safety information in the Summary of Product Characteristics (SmPC). Suspected adverse reactions should be reported via the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk or the Yellow Card app).

Hot Flushes and Mounjaro: What the Evidence Shows

Hot flushes (also called hot flashes)—are sudden sensations of intense warmth, typically affecting the face, neck, and chest, often accompanied by sweating and sometimes followed by chills. They are most commonly associated with hormonal changes, particularly the decline in oestrogen levels during the menopausal transition in women, but can also occur in men undergoing androgen deprivation therapy or due to other medical conditions.

Currently, hot flushes are not listed among the common, uncommon, or rare adverse effects in the UK SmPC for Mounjaro or Zepbound. The pivotal clinical trials evaluating tirzepatide for type 2 diabetes (SURPASS programme) and obesity (SURMOUNT programme) did not identify hot flushes as a significant treatment-emergent adverse event. However, it is important to recognise that clinical trials may not capture every possible side effect, particularly those that are rare or occur in specific subpopulations.

That said, some patients taking Mounjaro have anecdotally reported experiencing hot flushes or flushing sensations. These reports may reflect individual variation in drug response, coincidental timing with other life events (such as menopause), or indirect effects related to metabolic changes. While significant weight loss can influence various physiological processes, it's worth noting that in menopausal women, weight loss often improves rather than worsens vasomotor symptoms.

It is also worth considering that symptoms resembling hot flushes could be related to other factors, such as fluctuations in blood glucose levels, anxiety, dietary changes, or concurrent medications. A thorough clinical assessment is essential to determine the underlying cause of any new or worsening symptoms during treatment with Mounjaro.

Managing Hot Flushes While Taking Mounjaro

If you experience hot flushes while taking Mounjaro, there are several practical strategies that may help alleviate symptoms and improve your comfort. Lifestyle modifications are often helpful and include:

• Wearing lightweight, breathable clothing made from natural fibres such as cotton, and dressing in layers that can be easily removed

• Keeping your environment cool by using fans, opening windows, or adjusting air conditioning

• Avoiding known triggers such as spicy foods, caffeine, alcohol, and hot beverages

• Maintaining a healthy weight and engaging in regular physical activity, which can help regulate body temperature and improve overall wellbeing

• Practising stress-reduction techniques such as mindfulness, yoga, or deep breathing exercises, as stress and anxiety can exacerbate vasomotor symptoms

It is also important to monitor your blood glucose levels regularly, as recommended by your healthcare team. Hypoglycaemia or rapid fluctuations in blood sugar can sometimes cause sweating and sensations of warmth that may be mistaken for hot flushes. Ensuring stable glycaemic control may help reduce these symptoms.

If hot flushes are significantly affecting your quality of life, discuss this with your GP or diabetes specialist. They can review your medication regimen, assess for other potential causes (such as thyroid dysfunction or menopausal symptoms), and consider whether any adjustments are needed. Your healthcare provider may also review other medications you're taking that could trigger flushing, such as niacin or calcium channel blockers.

For menopausal hot flushes, in line with NICE guidance, hormone replacement therapy (HRT) is usually considered first-line treatment. When HRT is contraindicated or not tolerated, non-hormonal options such as certain SSRIs/SNRIs, gabapentin, or clonidine may be considered off-label after discussing risks and benefits. Cognitive behavioural therapy (CBT) can also be helpful as a supportive therapy.

Do not stop taking Mounjaro without consulting your healthcare professional, as abrupt discontinuation may lead to worsening glycaemic control or weight regain. Any concerns about side effects should be addressed through open communication with your medical team.

When to Seek Medical Advice About Hot Flushes

While hot flushes are often benign and manageable with lifestyle measures, there are certain circumstances in which you should seek prompt medical advice. Contact your GP or healthcare provider if:

• Hot flushes are severe, persistent, or significantly impacting your daily activities and quality of life

• You experience hot flushes accompanied by other concerning symptoms such as chest pain, palpitations, shortness of breath, dizziness, or fainting

• You notice unexplained weight loss (beyond what is expected with Mounjaro), night sweats, fever, or fatigue, which could indicate an underlying medical condition

• Hot flushes are associated with signs of hypoglycaemia such as tremor, confusion, sweating, or hunger—treat low blood glucose immediately with fast-acting carbohydrate (e.g., glucose tablets, fruit juice), recheck your levels after 15 minutes, and seek help if symptoms don't improve

• You develop new or worsening symptoms that you believe may be related to your medication

• You experience severe, persistent abdominal pain (with or without vomiting), which could indicate pancreatitis

• You develop symptoms of gallbladder disease such as pain in the upper right abdomen, fever, or jaundice

Call 999 immediately if you experience severe chest pain, signs of a heart attack or stroke, or severe breathlessness.

It is particularly important to seek medical review if you have not previously experienced hot flushes and they begin suddenly after starting Mounjaro, or if you are male and experiencing vasomotor symptoms without an obvious explanation. Your healthcare professional can conduct a thorough assessment, including a detailed history, physical examination, and appropriate investigations. For women over 45 with typical menopausal symptoms, hormone testing is not routinely recommended according to NICE guidance.

For patients with type 2 diabetes, NICE guidance recommends regular review and monitoring of treatment response, side effects, and overall cardiovascular risk. Use these routine appointments as an opportunity to discuss any symptoms you are experiencing. Your healthcare team can help determine whether hot flushes are related to Mounjaro, another medication, an underlying condition, or a natural physiological process such as menopause.

If you experience symptoms of a serious allergic reaction—such as difficulty breathing, swelling of the face or throat, or severe rash—seek emergency medical attention immediately. While rare, serious adverse effects require urgent evaluation and management.

Frequently Asked Questions