Ozempic (semaglutide) is a GLP-1 receptor agonist licensed in the UK for type 2 diabetes and weight management. Whilst clinical trials demonstrate cardiovascular benefits, some patients report palpitations or a racing heart after starting treatment. Does Ozempic make your heart race? Clinical evidence shows semaglutide can cause small increases in resting heart rate, typically a few beats per minute. Understanding whether symptoms represent true tachycardia, palpitations, or alternative causes is essential. This article examines the cardiovascular effects of Ozempic, when to seek medical help, and practical management strategies for heart-related symptoms.

Does Ozempic Make Your Heart Race?

Ozempic (semaglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for the treatment of type 2 diabetes mellitus and, at higher doses (as Wegovy), for weight management. Whilst cardiovascular benefits have been demonstrated in clinical trials—including reduced risk of major adverse cardiovascular events—some patients report experiencing a racing heart or palpitations after starting treatment.

Clinical trials have shown that semaglutide can cause small mean increases in resting heart rate (typically a few beats per minute). The Wegovy Summary of Product Characteristics (SmPC) specifically lists 'heart rate increased' as an adverse reaction, although tachycardia (rapid heart rate) is not listed as a common side effect in the Ozempic SmPC. Individual patient experiences vary considerably.

It is important to distinguish between true tachycardia—a sustained heart rate exceeding 100 beats per minute at rest—and palpitations, which are the subjective awareness of one's heartbeat. Palpitations can feel like fluttering, pounding, or racing sensations and may occur even when heart rate is within normal limits. Both warrant clinical assessment if persistent or accompanied by other symptoms.

Dehydration and gastrointestinal side effects are common with Ozempic, particularly during dose escalation. Nausea, vomiting, and diarrhoea can lead to fluid and electrolyte imbalances, which may secondarily affect heart rhythm and rate. Weight loss may also influence cardiovascular function in some patients, potentially contributing to awareness of heart rate changes.

Recognising Serious Side Effects: When to Seek Medical Help

Whilst most side effects of Ozempic are mild to moderate and self-limiting, certain cardiovascular symptoms require urgent medical evaluation. Patients should seek immediate medical attention by calling 999 or attending the nearest Accident & Emergency department if they experience:

• Chest pain or pressure, particularly if radiating to the arm, jaw, or back

• Severe shortness of breath or difficulty breathing at rest

• Dizziness, light-headedness, or fainting (syncope)

• Irregular heartbeat with symptoms such as chest pain or severe dizziness

Non-urgent but important symptoms that warrant contact with your GP or NHS 111 within 24–48 hours include:

• Persistent palpitations occurring daily or interfering with activities

• Sustained rapid heart rate at rest

• New-onset heart racing associated with anxiety or panic symptoms

• Palpitations accompanied by persistent nausea, vomiting, or inability to maintain hydration

• Any cardiovascular symptoms in patients with pre-existing heart disease

Your healthcare provider may arrange investigations such as an electrocardiogram (ECG), blood tests to assess electrolytes and thyroid function, or 24-hour Holter monitoring to characterise any rhythm disturbance. Patients with type 2 diabetes should have regular cardiovascular risk assessment, and any new cardiac symptoms should prompt thorough evaluation.

If you experience any suspected side effects from Ozempic, you can report them via the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk or via the Yellow Card app).

Managing Heart-Related Symptoms While Taking Ozempic

If you experience palpitations or a racing heart whilst taking Ozempic, several practical management strategies may help, though medical review remains essential:

Maintain adequate hydration: Gastrointestinal side effects are common, particularly during the first few weeks and after dose increases. Aim for adequate fluid intake throughout the day, increasing if experiencing nausea, vomiting, or diarrhoea. Oral rehydration solutions may be beneficial if symptoms are pronounced. People with heart failure, chronic kidney disease, or on fluid restriction should follow their healthcare provider's specific guidance on fluid intake.

Monitor your symptoms: Keep a diary noting when palpitations occur, their duration, associated activities (such as after meals or exercise), and any accompanying symptoms. This information is valuable for your healthcare provider in determining whether symptoms are related to Ozempic or have an alternative cause.

Review dose escalation: According to the Ozempic SmPC, treatment is typically initiated at 0.25 mg weekly for four weeks, then increased to 0.5 mg weekly, with further increases to 1 mg or 2 mg if needed. If cardiovascular symptoms emerge during dose escalation, your prescriber may recommend maintaining the current dose longer before increasing, or reducing back to the previous tolerated dose.

Avoid triggers: Caffeine, alcohol, and certain over-the-counter medications (such as decongestants containing pseudoephedrine) can exacerbate palpitations. Consider reducing or eliminating these whilst adjusting to Ozempic.

Blood glucose monitoring: Although hypoglycaemia is uncommon with Ozempic monotherapy, it can occur when combined with insulin or sulphonylureas. Low blood glucose can trigger compensatory tachycardia and palpitations. If you suspect hypoglycaemia, check your blood glucose if possible, take fast-acting glucose if levels are low, and discuss medication adjustments with your diabetes team.

Do not discontinue Ozempic abruptly without medical advice. If symptoms are troublesome, contact your prescriber to discuss whether temporary dose reduction, additional investigations, or alternative treatment options are appropriate.

Alternative Explanations for Increased Heart Rate

When patients report a racing heart after starting Ozempic, it is essential to consider alternative or contributing factors beyond the medication itself:

Anxiety and heightened awareness: Starting a new medication, particularly one associated with significant lifestyle changes and weight loss, can increase health anxiety. Patients may become more aware of normal heart rate variations, interpreting them as abnormal. Anxiety itself activates the sympathetic nervous system, genuinely increasing heart rate and creating a self-perpetuating cycle.

Thyroid dysfunction: Both hyperthyroidism and hypothyroidism can affect heart rate and rhythm. Patients with type 2 diabetes have increased prevalence of thyroid disorders. NICE Clinical Knowledge Summaries recommend thyroid function tests as part of the baseline investigation for unexplained palpitations.

Anaemia: Iron deficiency anaemia is common, particularly in women, and causes compensatory tachycardia as the heart works harder to deliver oxygen to tissues. Full blood count should be checked if palpitations persist.

Caffeine and stimulant intake: Patients pursuing weight loss may increase caffeine consumption or use energy drinks. These can significantly elevate heart rate, particularly in combination with reduced food intake.

Orthostatic tachycardia: Some patients may experience an exaggerated heart rate increase upon standing, particularly if dehydrated. In more persistent cases, this might represent postural tachycardia syndrome (PoTS), which requires specialist assessment. Symptoms typically improve with adequate hydration and gradual physical reconditioning.

Pre-existing cardiac conditions: Ozempic may be prescribed to patients with established cardiovascular disease. New symptoms may represent progression of underlying disease rather than medication effect. Comprehensive cardiovascular assessment, including echocardiography if indicated, may be warranted.

Your healthcare provider will consider these possibilities through careful history-taking, examination, and appropriate investigations to determine the cause of your symptoms and guide management decisions.

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