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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Mounjaro vs Wegovy — UK Price Comparison Chart
Both Mounjaro (tirzepatide) and Wegovy (semaglutide) are prescription weight loss injections available in the UK, but their costs differ significantly. If you're considering either medication, understanding the price comparison helps you make an informed decision. This guide breaks down UK pricing for both drugs, explains why costs vary, and shows you how to access them through NHS or private routes. Use our free GLP-1 weight loss calculator to estimate potential outcomes, then discuss options with your GP or a licensed prescriber.
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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 UK Pricing — Side-by-Side Comparison
Private prescription costs in the UK typically range:
- Mounjaro: £129–£320 per month (depending on dose and provider)
- Wegovy: £150–£300 per month (depending on dose and provider)
Mounjaro's starting dose (2.5 mg) costs less than Wegovy's maximum dose (2.4 mg). However, the highest Mounjaro dose (15 mg per week) tends to be more expensive than maximum Wegovy due to Mounjaro's dual GIP+GLP-1 mechanism requiring higher manufacturing complexity. NHS access is free at point of care but limited to specialist tier 3 weight management services with long waiting lists in many regions. Private pricing varies by provider, dose escalation speed, and whether you use a subscription service or pay per-prescription. Check with multiple GPhC-registered pharmacies for current rates—this is a competitive market with variation.
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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.
What Affects the Price You Pay for Each Medication
Several factors influence your final cost: dose level (higher doses cost more), prescription frequency (some services offer discounted packages for multiple months), pharmacy provider (prices vary between licensed online prescribers), and subscription vs pay-as-you-go models. NHS prescription costs are zero for weight management prescriptions through specialist services, though NHS access itself involves waiting lists and regional variation. A KwikPen (4-week supply) at 5 mg Mounjaro typically costs £129–£150 privately, while the same dose of Wegovy ranges £150–£170. As you titrate upward over weeks, monthly costs increase. Factor in the cost of ongoing clinical consultations if using private prescribing—some services bundle this, others charge separately.
- 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 Mounjaro cheaper than Wegovy in the UK?
Not necessarily. At starter doses, they're similarly priced (£129–£170/month). At maximum doses, Mounjaro (15 mg) can cost slightly more than Wegovy (2.4 mg) due to manufacturing complexity. The kwikpen dose you're prescribed—not the drug name—determines your actual cost. Compare prices across multiple GPhC-registered pharmacies before committing.
Can I get Mounjaro or Wegovy free on the NHS?
Yes, both are NHS-prescribable through specialist tier 3 weight management services. However, access varies widely by region and involves waiting lists that can extend many months. Not all NHS areas have equal access. Ask your GP about local specialist services, or contact your Integrated Care Board (ICB) directly about availability.
What's included in the private prescription cost?
Typically the medication itself (KwikPen) and initial prescription. Some private services include follow-up consultations and dose escalation support; others charge separately. Always clarify with your provider upfront whether monitoring, repeat consultations, and dose adjustments are included in the quoted price or cost extra.
How much does the dose titration phase cost?
You start on a low dose and increase weekly or every four weeks until reaching your maintenance dose. This typically takes 16–20 weeks. You pay per prescription (per KwikPen or per dose), so early-stage costs are lower. Budget for escalating costs as your dose climbs—use our GLP-1 weight loss calculator to project potential outcomes at different dose levels.
Which medication is better value for money?
This depends on your individual response, health goals, and budget. Clinical trials show Mounjaro achieved slightly higher average weight loss (~21% vs ~15%), but individual results vary greatly. Neither is objectively "better value"—a prescriber assesses which suits your health profile. Cost alone shouldn't drive the decision; effectiveness and tolerability matter more.
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.