Concerns occasionally arise about whether Ozempic (semaglutide) could cause seizures in people using this medication for type 2 diabetes. Ozempic is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK to improve blood glucose control in adults with type 2 diabetes mellitus. Whilst seizures are not listed as a recognised side effect in UK regulatory guidance, it is important to understand the evidence, potential indirect mechanisms, and when neurological symptoms warrant medical attention. This article examines the relationship between Ozempic and seizures, reviews established side effects, and provides guidance on safe medication use.

Understanding Ozempic and Its Primary Uses

Ozempic (semaglutide) is a prescription medicine licensed in the UK for the treatment of type 2 diabetes mellitus in adults. It belongs to a class of medications known as glucagon-like peptide-1 (GLP-1) receptor agonists, which work by mimicking the action of a naturally occurring hormone that regulates blood glucose levels.

The primary mechanism of action involves stimulating insulin secretion from the pancreas when blood glucose levels are elevated, whilst simultaneously suppressing the release of glucagon, a hormone that raises blood sugar. Ozempic also slows gastric emptying, which helps to reduce post-meal glucose spikes, and acts on appetite centres in the brain to promote satiety. These combined effects contribute to improved glycaemic control and often result in weight loss as a secondary benefit.

Ozempic is administered as a once-weekly subcutaneous injection, with a recommended starting dose of 0.25 mg for 4 weeks, followed by 0.5 mg. The dose may be increased to 1 mg once weekly and further to 2 mg once weekly if needed for additional glycaemic control. Dose adjustments are based on individual response and tolerability. In the UK, Ozempic is prescribed alongside diet and exercise modifications, and may be used alone or in combination with other diabetes medications such as metformin or insulin.

The National Institute for Health and Care Excellence (NICE) includes semaglutide in its guidance for type 2 diabetes management, particularly for patients who require additional glycaemic control or who may benefit from weight reduction. It is important to note that Ozempic is specifically licensed for diabetes treatment only; the same active ingredient (semaglutide) is available under a different brand name (Wegovy) for weight management, with separate licensing and dosing regimens.

Could Ozempic Cause Seizures? Examining the Evidence

Concerns occasionally arise regarding potential neurological effects of medications, including whether Ozempic could cause seizures. It is important to examine the available evidence carefully and distinguish between established causal relationships and coincidental occurrences.

Currently, there is no official link established between Ozempic and seizures in the product's Summary of Product Characteristics (SmPC) or in guidance from the Medicines and Healthcare products Regulatory Agency (MHRA). Seizures are not listed among the known or common adverse effects of semaglutide. The extensive clinical trial programme that supported Ozempic's licensing did not identify seizures as a treatment-related adverse event.

However, it is theoretically possible for any medication to be associated with rare, idiosyncratic reactions in susceptible individuals. Additionally, certain indirect mechanisms warrant consideration. For instance, severe hypoglycaemia (very low blood sugar) can, in rare cases, trigger seizures. Whilst Ozempic alone carries a low risk of hypoglycaemia due to its glucose-dependent mechanism of action, the risk increases when it is used in combination with insulin or sulfonylureas. Patients experiencing severe hypoglycaemic episodes may, in exceptional circumstances, develop neurological symptoms including seizures.

Another consideration is electrolyte disturbance . Severe gastrointestinal side effects such as persistent vomiting or diarrhoea—which can occur with GLP-1 receptor agonists—may lead to dehydration and electrolyte imbalances. Significant sodium abnormalities, for example, could theoretically lower seizure threshold, though this would be an indirect rather than direct drug effect.

Patients with pre-existing seizure disorders or risk factors for seizures should discuss their full medical history with their prescribing clinician. If neurological symptoms occur while taking Ozempic, blood glucose should be checked promptly to rule out hypoglycaemia. Any new or unusual neurological symptoms should be reported promptly to a healthcare professional for proper evaluation.

Recognised Side Effects of Ozempic in the UK

Understanding the established side effect profile of Ozempic helps patients and healthcare professionals distinguish between expected reactions and unusual symptoms that may require further investigation.

Gastrointestinal effects are the most commonly reported adverse reactions with Ozempic. These include:

• Nausea (very common, affecting more than 1 in 10 people)

• Diarrhoea (very common)

• Vomiting (common, affecting up to 1 in 10 people)

• Constipation (common)

• Abdominal pain (common)

• Dyspepsia (indigestion)

These gastrointestinal symptoms typically occur during dose initiation or escalation and often diminish over time as the body adjusts to the medication. Starting with a low dose and increasing gradually, as recommended in the prescribing information, helps to minimise these effects.

Hypoglycaemia risk varies depending on concomitant diabetes medications. When Ozempic is used as monotherapy or with metformin, the risk of low blood sugar is minimal. However, when combined with insulin or sulfonylureas, the risk increases, and dose adjustments of these other medications may be necessary.

Other recognised side effects include:

• Injection site reactions (redness, itching, bruising)

• Decreased appetite

• Gallbladder disease (cholelithiasis, cholecystitis)

Rare but serious adverse effects that require immediate medical attention include:

• Pancreatitis (severe, persistent abdominal pain) – semaglutide should be discontinued if pancreatitis is suspected

• Diabetic retinopathy complications (in patients with pre-existing retinopathy)

• Acute kidney injury (particularly in the context of severe dehydration)

• Severe allergic reactions (anaphylaxis, angioedema)

Patients should be counselled about these potential effects before starting treatment and provided with clear guidance on recognising symptoms that warrant urgent medical review.

When to Seek Medical Advice While Taking Ozempic

Knowing when to contact a healthcare professional is essential for safe medication use. Patients taking Ozempic should seek immediate medical attention (by calling 999 or attending A&E) if they experience:

• Signs of a severe allergic reaction, including difficulty breathing, swelling of the face, lips, tongue or throat, or severe skin rash

• Severe hypoglycaemia with inability to swallow, seizures or loss of consciousness (particularly relevant for those on insulin or sulfonylureas)

• Ongoing seizures or loss of consciousness

Patients should contact their GP or NHS 111 urgently if they experience:

• Severe, persistent abdominal pain that may radiate to the back, potentially indicating pancreatitis – stop taking Ozempic and seek urgent assessment

• Persistent vomiting or diarrhoea lasting more than 24 hours, which may lead to dehydration

• Symptoms of dehydration, such as extreme thirst, very dark urine, dizziness on standing, or reduced urine output

• Visual changes, particularly if they have pre-existing diabetic retinopathy

• Signs of gallbladder problems, such as pain in the upper right abdomen, fever, or yellowing of the skin or eyes

For hypoglycaemia (blood glucose below 4 mmol/L):

• Take fast-acting carbohydrates (e.g., glucose tablets, fruit juice)

• Follow with longer-acting carbohydrates once symptoms improve

• Seek medical help if symptoms don't improve or recur

• Have someone call 999 if unable to swallow or if unconscious

Routine follow-up with the prescribing clinician should occur if:

• Gastrointestinal side effects persist beyond the first few weeks or significantly impact quality of life

• There are concerns about medication effectiveness or blood glucose control

• New medications are started that might interact with Ozempic

• There are questions about injection technique or dose adjustments

Patients should never stop Ozempic abruptly without medical guidance, as this may lead to deterioration in glycaemic control. Any concerns about continuing treatment should be discussed with the prescribing healthcare professional, who can assess the risk-benefit balance and consider alternative management strategies if necessary.

Safety Monitoring and MHRA Guidance for Ozempic

The Medicines and Healthcare products Regulatory Agency (MHRA) continuously monitors the safety of all licensed medicines in the UK, including Ozempic, through its Yellow Card scheme. This pharmacovigilance system collects reports of suspected adverse drug reactions from healthcare professionals and patients, enabling the identification of previously unrecognised safety signals.

Healthcare professionals and patients are encouraged to report any suspected adverse reactions to Ozempic via the Yellow Card scheme, available online at yellowcard.mhra.gov.uk or through the Yellow Card app.

The MHRA regularly reviews accumulating safety data and issues Drug Safety Updates when new information emerges that affects prescribing practice. Healthcare professionals should remain alert to these communications and adjust their clinical practice accordingly.

NICE guidance (NG28) recommends that patients starting GLP-1 receptor agonists like Ozempic should have:

• Baseline assessment including HbA1c, renal function, and body weight

• Regular monitoring of glycaemic control and tolerability

• Review at 6 months to assess treatment response (defined as HbA1c reduction of at least 11 mmol/mol and weight loss of at least 3% of initial body weight)

• Ongoing assessment of cardiovascular risk factors

Patients with pre-existing conditions require particular consideration. Those with a history of pancreatitis, severe gastrointestinal disease, or diabetic retinopathy should be monitored more closely. Renal function should be monitored in patients at risk of dehydration due to gastrointestinal side effects.

It is important to note that Ozempic is not indicated for type 1 diabetes or for treating diabetic ketoacidosis.

The European Medicines Agency (EMA) also maintains oversight of semaglutide's safety profile across Europe, and any significant safety concerns identified in other jurisdictions are evaluated for relevance to UK practice. This collaborative international approach to pharmacovigilance helps ensure that emerging safety signals are detected and acted upon promptly, maintaining the highest standards of patient safety.

Frequently Asked Questions