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
Free tracker included with every download this week
Mounjaro vs Wegovy — Current UK Prices and Costs
If you're considering weight loss injections in the UK, understanding the cost difference between Mounjaro (tirzepatide) and Wegovy (semaglutide) is essential. Both are prescription-only GLP-1 receptor agonist medications — with Mounjaro also working as a dual GIP agonist — and prices vary significantly depending on whether you access them through the NHS or private prescribing. This guide breaks down current pricing, what affects costs, and how to understand the financial commitment involved in either treatment option.
10,000+ calculations today · NHS-aligned thresholds · 100% free
Calculate Your BMI Instantly
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.
Mounjaro and Wegovy Pricing — What You'll Actually Pay
Current private prescribing costs in the UK typically range from £129 to £320 per month for either medication, depending on the dose and provider. Mounjaro doses escalate from 2.5 mg to a maximum of 15 mg, whilst Wegovy escalates from 0.25 mg to 2.4 mg — higher doses cost more because they contain more active ingredient.
A typical pricing structure looks like this: starting doses (2.5 mg Mounjaro or 0.25 mg Wegovy) cost around £130–150 monthly, whilst maintenance doses (10–15 mg Mounjaro or 1.7–2.4 mg Wegovy) cost £250–320 monthly. Each KwikPen or auto-injection pen contains four weeks of doses, so you'll typically purchase monthly supplies.
- Mounjaro (tirzepatide): Available via NHS specialist weight management services in some regions — waiting lists apply — or private prescribing without NHS referral
- Wegovy (semaglutide): Similarly accessed through NHS services or private online prescribing services following clinical assessment
- Ozempic confusion: Ozempic (also semaglutide) is cheaper but licensed only for type 2 diabetes, not weight management — using it off-label for weight loss is not recommended and prescribers should not suggest this route
Costs exclude consultation fees (typically £20–50 for initial assessment), prescription fees (standard NHS rate of £9.90 if available on NHS), and ongoing GP reviews if needed.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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.
Clinical Trial Results — Why Price Differences Matter Less Than Efficacy
Both medications work, but through different mechanisms, which is why side-by-side price comparison alone isn't enough. Clinical trial data shows: Mounjaro (SURMOUNT-1 trial) delivered average weight loss of 15–21% of body weight over 72 weeks, whilst Wegovy (STEP-1 trial) showed approximately 14.9% loss at 68 weeks. These are averages — individual results vary significantly.
The choice between them depends less on current pricing and more on: which medication your prescriber assesses as suitable for you; your personal health profile; whether you're eligible for NHS access in your region; and which side effect profile you're more comfortable managing. Use our free GLP-1 weight loss calculator to explore potential outcomes with either medication, and discuss current costs and availability with your prescriber or the private clinic conducting your assessment.
- 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's the difference between Mounjaro and Wegovy pricing?
Both cost roughly £129–320/month privately depending on dose. Mounjaro is a dual GIP+GLP-1 agonist (doses 2.5–15 mg weekly), Wegovy is GLP-1 only (0.25–2.4 mg weekly). Higher doses cost more. Specific prices vary by prescribing service — always ask for a full cost breakdown before starting treatment.
Can I get Mounjaro or Wegovy free on the NHS?
Both are available through NHS specialist (tier 3) weight management services for eligible adults. However, NHS availability varies significantly by region and waiting lists can be lengthy. Your GP can refer you if you meet NHS eligibility criteria — typically BMI 30+ or BMI 27+ with weight-related health conditions.
Are there cheaper weight loss injection alternatives?
Saxenda (liraglutide) is another GLP-1 injection licensed for weight management in the UK, and may have different pricing. However, it's a daily injection rather than weekly like Mounjaro and Wegovy. Always compare total cost per week, not just per dose, and discuss all available options with your prescriber.
What's included in the monthly cost?
Monthly pricing (£129–320) covers the medication supply only — typically a 4-week KwikPen or auto-injection pen. It does NOT include: initial consultation fees (£20–50), GP review appointments, or NHS prescription charges if eligible. Check with your prescribing service for a full cost breakdown.
Should I choose based on price alone?
No. Whilst price matters, suitability is more important. Your prescriber assesses your health history, other medications, and side effect tolerance to recommend the better option for you. Both delivered significant weight loss in trials — individual results vary. Use the BMI calculator and discuss with your prescriber which is more appropriate.
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.