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
If you're considering GLP-1 weight loss medication in the UK, cost and access are key factors. Both Wegovy (semaglutide) and Mounjaro (tirzepatide) are prescription-only medicines available through NHS specialist services or private prescription routes. Prices, eligibility, and how quickly you can access treatment vary significantly between these two options. This guide explains what each costs, how to access them, and what affects the total price you'll pay.
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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 and Mounjaro Private Prescription Costs in the UK
Wegovy (semaglutide) private cost: Typically ranges from £140 to £320 per month depending on dose and provider. Starting doses (0.25–0.5 mg) cost less; maintenance doses (1.7–2.4 mg) cost more. A full treatment course can cost £1,500 to £3,500 over several months.
Mounjaro (tirzepatide) private cost: Usually ranges from £129 to £299 per month for private prescription. Like Wegovy, starting doses cost less than maintenance doses. A typical treatment course costs £1,200 to £3,000.
- Prices vary between private prescribing services — there is no fixed NHS price for private prescriptions
- Most providers charge per dose (per 4-week supply)
- Some offer package deals or subscription discounts for longer commitments
- Prices do not include your GP review appointments if needed
Use our GLP-1 weight loss calculator to estimate potential weight loss at different doses, which can help you compare the cost-benefit of each medication.
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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.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
NHS Access vs Private Prescription Routes
NHS route (free): Available through tier 3 specialist weight management services following GP referral. However, waiting lists can be 6–18 months depending on your region, and not all ICBs fund both medications equally. Mounjaro KwikPen access through the NHS is expanding but availability is inconsistent. When approved, medication costs you nothing.
Private route (paid): Access through online consultations with UK-licensed prescribers within 1–7 days. You pay per dose upfront. No NHS referral required. More flexible but requires self-funding. Prescription is issued only after clinical assessment of your BMI, health history, and eligibility.
Calculate your BMI using our free BMI calculator to check whether you meet the standard eligibility threshold (BMI 30+, or 27+ with weight-related health conditions) before booking a private consultation.
- 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 in the UK?
Mounjaro is often slightly cheaper (£129–£299/month) compared to Wegovy (£140–£320/month) through private prescription, but the difference is usually only £10–£30 per month. Total cost depends on which dose you need and how long you take it. Both are free via NHS if you're eligible and can access specialist services.
Can I get Wegovy on the NHS?
Yes, Wegovy is available through NHS tier 3 specialist weight management services, but only following GP referral and assessment. Availability varies by region and waiting times can be very long (6–18 months in many areas). Private prescription is faster but costs £140–£320/month.
What's the difference between Mounjaro KwikPen and Wegovy pen?
Mounjaro uses a KwikPen (holds 4 weeks of doses at one strength); Wegovy uses an auto-injector pen. Both are once-weekly injections. Mounjaro is a dual GIP/GLP-1 agonist; Wegovy is a GLP-1 agonist only. Mounjaro often requires fewer dose escalations to reach maximum effect.
Do private prescription prices include GP consultations?
No. Private prescription costs (£129–£320/month) are for the medication only. Some providers include the initial online prescriber consultation, but ongoing GP monitoring appointments are separate. Ask your provider what's included before paying.
How do I know if I'm eligible for either medication?
You need a BMI of 30 or above, or 27+ with weight-related health conditions (diabetes, high blood pressure, sleep apnoea, heart disease). A UK-licensed prescriber assesses your eligibility during an online consultation. Use our BMI calculator to check your starting point before applying.
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.