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 vs Mounjaro Cost in the UK
Both Wegovy (semaglutide) and Mounjaro (tirzepatide) are prescription-only weight loss injections available in the UK, but their costs differ significantly depending on whether you access them through the NHS or privately. Understanding the pricing, availability, and what affects cost can help you make an informed decision about which option suits your situation. This guide compares both medications transparently, covering NHS access, private pricing, and the factors that influence the final cost of each treatment.
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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.
NHS Access and Availability for Both Medications
Both Wegovy and Mounjaro are available through the NHS, but access varies significantly by region and wait times can be substantial. NHS prescription is typically through tier 3 specialist weight management services, not standard GP prescription. You'll need a referral from your GP, and eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions (such as type 2 diabetes, high blood pressure, or cardiovascular disease).
NICE has approved both tirzepatide (Mounjaro) and semaglutide (Wegovy) for NHS use, but regional availability through integrated care boards (ICBs) varies dramatically. Some areas have established specialist services with reasonable waiting lists; others have waiting lists exceeding 18 months or limited capacity. The NHS cost to you is zero — but access depends entirely on your local NHS commissioning decisions and current service capacity.
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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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Private Cost Comparison: Wegovy vs Mounjaro
Private pricing in the UK ranges from approximately £129 to £320 per month, depending on the dose, provider, and whether you're starting or at maintenance dose. Mounjaro typically costs £200–£250 per month at standard maintenance doses (10–15 mg), while Wegovy ranges from £150–£320 per month depending on the dose level. Both require an online consultation with a UK-licensed prescriber and a prescription from a GPhC-registered pharmacy — there are no upfront setup costs beyond the consultation and medication itself. Try our GLP-1 weight loss calculator to estimate potential outcomes with either medication before committing to cost.
Several factors affect private cost: dose level (both medications are titrated upwards, so starting doses cost less than maximum doses), provider (competition exists, so prices vary between different online prescribing services), and bulk discounts (some providers offer discounts for 3-month or 6-month prescriptions). Most private providers require an initial consultation (£50–£150) plus monthly costs thereafter. Both medications use pre-filled pens — Mounjaro in a KwikPen and Wegovy in an auto-injection pen — with no additional supplies needed beyond the pen itself.
- 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.
Is Wegovy or Mounjaro cheaper on the NHS?
Both are free on the NHS if prescribed through specialist weight management services. However, NHS access depends on your ICB's commissioning decisions and can involve lengthy waiting lists. Your GP will refer you to your local tier 3 service, where a prescriber will assess eligibility based on your BMI and health conditions.
What's the typical monthly cost of Mounjaro privately in the UK?
Private Mounjaro typically costs £200–£250 per month at maintenance doses (10–15 mg). Starting doses cost less. Prices vary between providers, and some offer discounts for 3 or 6-month bundles. Always confirm the exact price with your chosen provider before starting.
How much does Wegovy cost privately in the UK?
Wegovy ranges from approximately £150–£320 per month depending on your dose level. Starting doses are cheaper than the maximum 2.4 mg maintenance dose. Private prescribing services offer consultations (typically £50–£150) plus monthly medication costs. Prices vary between providers.
Why is there a difference in cost between Wegovy and Mounjaro?
Manufacturing costs, manufacturer pricing strategies, and market competition affect pricing. Mounjaro (Eli Lilly) and Wegovy (Novo Nordisk) are different medications with different mechanisms — Mounjaro is a dual GIP/GLP-1 agonist, Wegovy is GLP-1 only. Pricing reflects these differences and competitive positioning.
Can I switch between Wegovy and Mounjaro to save money?
Switching between medications should only be managed by your prescriber based on clinical need, not cost. Approximate dose equivalences exist, but there's no official conversion chart. If cost is a concern, discuss options with your prescriber or explore whether NHS access might be faster in your area than alternatives.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.