Mounjaro (tirzepatide) and Ozempic (semaglutide) are injectable medications licensed for type 2 diabetes that have gained attention for weight management effects. Understanding the cost differences between these treatments in the UK is essential for patients considering private prescriptions or navigating NHS eligibility. Private prescription prices typically range from £150–£250 monthly for Ozempic and £180–£299 for Mounjaro, though NHS access depends on strict clinical criteria. This article examines the comparative costs, clinical effectiveness, NHS availability, and value considerations to help UK patients make informed decisions about these increasingly sought-after medications.

Understanding Mounjaro and Ozempic: What They Are

Mounjaro (tirzepatide) and Ozempic (semaglutide) are both injectable medications originally developed for managing type 2 diabetes, though they have gained significant attention for their weight loss effects. Both belong to a class of drugs that mimic naturally occurring hormones involved in blood sugar regulation and appetite control, but they work through slightly different mechanisms.

Ozempic is a GLP-1 receptor agonist (glucagon-like peptide-1), which works by stimulating insulin secretion when blood glucose levels are elevated, suppressing glucagon release, slowing gastric emptying, and reducing appetite through effects on the brain's satiety centres. It has been available in the UK since 2018 and is administered once weekly via subcutaneous injection. Importantly, Ozempic is licensed only for type 2 diabetes treatment. The active ingredient, semaglutide, is also available as Wegovy (2.4 mg)—a higher-dose formulation specifically licensed for weight management.

Mounjaro represents a newer therapeutic approach as a dual GLP-1 and GIP receptor agonist (glucose-dependent insulinotropic polypeptide). By activating both incretin pathways simultaneously, tirzepatide offers enhanced metabolic effects compared to GLP-1 agonists alone. This dual action may result in greater improvements in glycaemic control and more substantial weight reduction. Mounjaro received UK marketing authorisation from the MHRA in October 2023 for type 2 diabetes management.

Both medications require subcutaneous injection, typically in the abdomen, thigh, or upper arm, and are generally started at lower doses with gradual titration to minimise gastrointestinal side effects. Neither medication should be used during pregnancy or breastfeeding, and women of childbearing potential should use effective contraception. Semaglutide should be discontinued at least 2 months before a planned pregnancy, and tirzepatide at least 1 month before.

NHS Availability and Prescription Criteria in the UK

Access to Mounjaro and Ozempic through the NHS is governed by eligibility criteria established by NICE (National Institute for Health and Care Excellence), with implementation managed by local integrated care boards (ICBs).

For type 2 diabetes management, NICE guideline NG28 recommends GLP-1 receptor agonists like Ozempic (semaglutide) when:

• Used as part of triple therapy (with metformin and another oral drug) when dual therapy has not achieved adequate glycaemic control (typically HbA1c ≥58 mmol/mol)

• The patient has a BMI ≥35 kg/m² (adjusted by 2.5 kg/m² lower for people from South Asian, Chinese, Black African and Caribbean backgrounds) or specific medical problems associated with obesity

• Insulin would have significant occupational implications or weight loss would benefit obesity-related comorbidities

Importantly, NICE requires a treatment review after 6 months. GLP-1 receptor agonists should only be continued if the person has had a beneficial metabolic response (a reduction of at least 11 mmol/mol [1.0%] in HbA1c and weight loss of at least 3% from initial body weight).

Mounjaro has similarly been recommended by NICE for type 2 diabetes. NICE Technology Appraisals for both medications are subject to mandatory NHS funding within the implementation period, though local formularies may influence which specific agent is offered first.

For weight management specifically, Ozempic is not licensed or approved on the NHS. Wegovy (semaglutide 2.4 mg) has NICE approval for weight management in adults with at least one weight-related comorbidity and either BMI ≥35 kg/m² or BMI ≥30 kg/m² with specific conditions. However, NHS access to Wegovy remains limited due to supply constraints and phased implementation.

Both medications have experienced supply issues affecting NHS availability. Patients with established cardiovascular disease may be prioritised for GLP-1 receptor agonists with proven cardiovascular benefits, in line with NICE guidance.

Patients seeking these medications for weight loss without meeting diabetes criteria typically need to pursue private prescriptions. Consult your GP or diabetes specialist to determine NHS eligibility.

Mounjaro vs Ozempic Cost UK: Private Prescription Prices

For patients pursuing private prescriptions, the cost difference between Mounjaro and Ozempic represents a significant consideration. Private prescription prices in the UK vary considerably depending on the provider, dosage, and whether the service includes medical consultations and monitoring. These prices are examples as of early 2024 and may change.

Ozempic private costs typically range from £150 to £250 per month for maintenance doses (0.5 mg or 1 mg weekly). Some private clinics offer package deals that include initial consultations, follow-up appointments, and ongoing prescriptions, which may cost between £200–£300 monthly. The starting dose (0.25 mg) may be slightly less expensive. Patients should note that these are ongoing costs, as treatment is generally long-term to maintain benefits.

Mounjaro private costs are generally comparable or slightly higher, ranging from £180 to £299 per month depending on the dose strength (ranging from 2.5 mg up to 15 mg weekly). As a newer medication, Mounjaro may command premium pricing at some private clinics, particularly those offering comprehensive weight management programmes. Initial consultation fees typically add £50–£150 to first-month costs.

Additional costs to consider include:

• Initial medical assessment and blood tests (£100–£200)

• Follow-up consultations every 3–6 months (£50–£100 per visit)

• Sharps disposal containers for used injection pens (available free via local council schemes or pharmacies)

• Potential costs for managing side effects

Importantly, NHS prescription exemptions and prepayment certificates do not apply to private prescriptions—these costs are fully self-funded. Some private providers offer subscription models with monthly direct debits, whilst others require upfront payment for 3–6 month supplies.

Online pharmacies and telehealth services may offer lower prices (sometimes £120–£180 monthly) but patients should verify these are registered with the General Pharmaceutical Council (GPhC) through their online register. All medications require proper storage (refrigeration until first use), and patients should follow UK guidelines for safe sharps disposal.

Effectiveness and Clinical Differences Between the Two

Clinical trial evidence demonstrates that both medications are highly effective for glycaemic control and weight reduction, though Mounjaro appears to offer superior outcomes in direct comparisons for type 2 diabetes, likely due to its dual incretin mechanism.

For type 2 diabetes management, the SURPASS clinical trial programme showed that Mounjaro achieved greater HbA1c reductions compared to semaglutide 1 mg (Ozempic). In the SURPASS-2 trial, patients taking Mounjaro 15 mg achieved average HbA1c reductions of 2.5% from baseline, compared to 1.9% with semaglutide 1 mg. Higher proportions of patients on Mounjaro also achieved target HbA1c levels below 53 mmol/mol (7.0%).

For weight loss, Mounjaro demonstrated superior results in diabetes patients. In SURPASS-2, patients on the highest Mounjaro dose lost an average of 11.2 kg over 40 weeks, compared to 5.7 kg with semaglutide 1 mg. The SURMOUNT clinical programme, evaluating Mounjaro specifically for weight management in people without diabetes, showed substantial weight reductions. While cross-trial comparisons should be interpreted cautiously, both medications can produce clinically meaningful weight loss.

Side effect profiles are similar for both medications, with gastrointestinal symptoms being most common:

• Nausea (reported by 15–30% of patients)

• Diarrhoea (12–20%)

• Constipation (10–15%)

• Abdominal discomfort

• Reduced appetite

These effects typically diminish over time and can be minimised through gradual dose escalation. Additional important safety considerations include:

• Risk of hypoglycaemia when used with insulin or sulfonylureas (dose adjustments may be needed)

• Pancreatitis and gallbladder disease risks

• Potential worsening of diabetic retinopathy, particularly with rapid improvements in blood glucose

• Dehydration risk that may lead to acute kidney injury

Both medications carry precautions regarding thyroid C-cell tumours based on animal studies. Patients should report any symptoms such as a lump in the neck, persistent hoarseness, or difficulty swallowing. If you experience severe or persistent side effects, contact your healthcare provider promptly.

Which Treatment Offers Better Value for UK Patients?

Determining which medication offers better value requires balancing clinical effectiveness, cost, individual response, and accessibility—a calculation that varies considerably between patients depending on their specific circumstances and funding route.

From a clinical effectiveness perspective, Mounjaro's superior glycaemic control and weight loss outcomes in type 2 diabetes suggest it may offer better clinical value for some patients, particularly those who have not achieved adequate results with other treatments. However, individual responses vary, and the clinical benefits must be weighed against costs and tolerability.

For NHS patients meeting eligibility criteria, the choice may be determined by local formulary decisions and supply availability. Where both are available, clinicians typically consider individual patient factors including BMI, HbA1c levels, previous treatment responses, and tolerability. Remember that NHS treatment with GLP-1 receptor agonists is subject to the 6-month continuation rule (requiring ≥11 mmol/mol HbA1c reduction and ≥3% weight loss).

For private patients, cost-effectiveness calculations become more personal. If Mounjaro costs £50–£100 more monthly but delivers greater clinical benefits, some patients may consider this worthwhile. However, others achieving satisfactory results with Ozempic may prefer the lower ongoing costs. A 12-month course of Ozempic might cost £1,800–£3,000 privately, compared to £2,160–£3,588 for Mounjaro—a difference of £360–£588 annually.

Practical considerations also affect value:

• Availability: Both medications have experienced supply constraints at various times

• Tolerability: Individual side effect experiences may make one preferable regardless of cost

• Treatment goals: Patients primarily seeking diabetes control versus weight loss may prioritise differently

• Licensing: For weight management specifically, Wegovy is the licensed semaglutide product

Patient safety advice: Whichever medication you consider, ensure prescribing occurs through legitimate medical channels with proper monitoring. If you experience side effects, report them through the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk). Regular follow-up appointments are essential to monitor effectiveness, adjust dosing, and identify any adverse effects early. Never purchase these medications from unregulated online sources, as counterfeit versions pose serious health risks.

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