The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Wegovy Weight Loss Prices and How It Compares to Mounjaro
Wegovy (semaglutide) is a prescription-only weekly weight loss injection licensed in the UK, with pricing typically ranging from £150–£300 per month depending on dose and provider. If you're considering a weekly weight loss injection, you may want to compare it with Mounjaro (tirzepatide), which works through a different mechanism and may suit different individuals. This guide explains UK pricing, eligibility, and how the two medications compare based on clinical trial evidence — helping you understand what to discuss with your prescriber.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Wegovy vs Mounjaro: Mechanism, Doses, and Clinical Results
Wegovy (semaglutide) is a GLP-1 receptor agonist, meaning it activates a single natural hormone pathway to reduce appetite and support feeling fuller. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, activating two hormone pathways, which may explain why some clinical trials showed slightly higher average weight loss.
Wegovy doses: 0.25 mg → 0.5 mg → 1 mg → 1.7 mg → 2.4 mg (maximum), escalated over approximately 16 weeks.
Mounjaro doses: 2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg (maximum), escalated over approximately 20 weeks.
Clinical trial weight loss (STEP trial for Wegovy): Approximately 14.9% average body weight loss at 68 weeks on 2.4 mg alongside a reduced-calorie diet and increased physical activity. Mounjaro (SURMOUNT trial): Approximately 15–21% average body weight loss depending on dose. Individual results vary significantly.
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How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
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UK Pricing, Eligibility, and Prescriber Assessment
Wegovy pricing in the UK typically ranges from approximately £150–£220 per month for standard doses through private prescribing services, though costs vary by provider and dose strength. Mounjaro prices are broadly similar, around £150–£280 per month. Both are prescription-only medicines requiring a clinical assessment before being prescribed — your prescriber will assess your BMI, health history, and any weight-related conditions to determine suitability.
UK eligibility: Adults with BMI 30 or above (or 27+ with weight-related conditions) may be eligible for either medication. For South Asian, Chinese, Black African, or Black Caribbean backgrounds, lower BMI thresholds may apply. Both medications are used alongside dietary changes and increased physical activity — neither is a standalone treatment. Try our GLP-1 weight loss calculator to explore potential results at different doses, or use our BMI calculator to check your starting point.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
What is the main difference between Wegovy and Mounjaro?
Wegovy is a GLP-1 receptor agonist (single mechanism), while Mounjaro is a dual GIP and GLP-1 receptor agonist (two mechanisms). Both are weekly injections licensed for weight management in the UK. The dual mechanism of Mounjaro may explain slightly higher average weight loss in clinical trials, but individual results vary and the choice depends on your specific health profile and prescriber assessment.
How much does Wegovy cost per month in the UK?
Wegovy typically costs £150–£220 per month through private prescribing services in the UK, depending on dose strength and provider. Costs are subject to change. NHS access is available through specialist weight management services in some regions, though waiting lists can be lengthy. Your prescriber can discuss cost options and what is available in your area.
Is Wegovy available through the NHS?
Wegovy (semaglutide) is approved by NICE for NHS use within specialist tier 3 weight management services. However, NHS availability is limited and varies significantly by region and ICB. Many areas have long waiting lists. Most people currently access Wegovy privately through a UK prescriber following an online clinical assessment.
Which medication causes more weight loss — Wegovy or Mounjaro?
Clinical trials showed Mounjaro achieved slightly higher average weight loss (15–21%) compared to Wegovy (14.9%), likely due to the dual mechanism. However, individual results vary considerably based on starting weight, lifestyle adherence, and personal response to the medication. Your prescriber will discuss which is most suitable for you.
Can I switch from Wegovy to Mounjaro or vice versa?
Switching between Wegovy and Mounjaro is possible but must be managed by your prescriber — there is no official conversion chart. If you wish to switch, discuss it with your healthcare provider or prescriber, who can assess whether the change is appropriate for you and manage the transition safely.
Ready to take control of your weight loss journey?
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