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 5mg best price in the UK — what you need to know
Finding the best price for Mounjaro 5mg in the UK requires understanding both NHS access and private prescribing options. The 5mg dose is typically the first maintenance dose after the initial 2.5mg starting phase, and pricing varies significantly depending on whether you're accessing treatment through the NHS or private online prescribing services. This guide compares Mounjaro directly with Wegovy (semaglutide) — another UK-licensed weight loss injection — to help you understand the key differences in cost, mechanism, and clinical evidence.
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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.
Mounjaro 5mg vs Wegovy — mechanism and clinical trial comparison
Mounjaro (tirzepatide) works as a dual GIP and GLP-1 receptor agonist, activating two natural hormone pathways that regulate appetite and blood sugar. The SURMOUNT-1 clinical trial showed that 5mg Mounjaro resulted in an average weight loss of approximately 15% body weight over 72 weeks, alongside a reduced-calorie diet and increased physical activity.
Wegovy (semaglutide) is a GLP-1 receptor agonist only — activating a single hormone pathway. The STEP-1 clinical trial showed approximately 14.9% average weight loss at the maximum 2.4mg dose. At equivalent early doses (Wegovy 0.5mg is roughly comparable to Mounjaro 5mg), weight loss outcomes in trials were broadly similar, though individual results vary significantly.
- Mounjaro: once-weekly injection, 2.5mg–15mg dose range
- Wegovy: once-weekly injection, 0.25mg–2.4mg dose range
- Both require prescription and clinical assessment
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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, access routes, and prescriber considerations
NHS access: Both medications are available through NHS specialist tier 3/4 weight management services, but availability and waiting times vary significantly by region. NICE has approved tirzepatide for NHS use, though many areas have limited capacity.
Private access: Mounjaro 5mg typically costs £180–£240 per month through private online prescribing (costs vary by provider and KwikPen availability). Wegovy pricing is similar at comparable doses. A UK-licensed prescriber will assess your eligibility based on BMI (30 or above, or 27 with weight-related health conditions) and medical history. Use our free GLP-1 weight loss calculator to explore projected outcomes with different doses, and consult your GP or a licensed prescriber to determine which medication suits your individual circumstances.
- 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 5mg cheaper than Wegovy in the UK?
Private pricing for Mounjaro 5mg and equivalent Wegovy doses is broadly similar, ranging from £180–£240 monthly depending on the provider. NHS pricing depends on your regional specialist service — availability varies significantly across the UK. Individual patient eligibility and prescriber recommendation determine which medication is suitable, not price alone.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP+GLP-1 agonist; Wegovy (semaglutide) is GLP-1 only. Clinical trials showed similar average weight loss at comparable doses (15% vs 14.9%). The main differences are mechanism, maximum dose (15mg vs 2.4mg), and manufacturer. Both require prescription and clinical assessment.
How long does Mounjaro 5mg take to work?
Most people notice appetite changes within days to weeks of starting, but significant weight loss typically takes 4–8 weeks. The 5mg dose is a maintenance dose (after the 2.5mg starting phase), so you may have already felt effects at the lower dose. Track your progress with our free progress tracker to monitor changes over time.
Can I get Mounjaro on the NHS?
Yes, tirzepatide (Mounjaro) is approved by NICE for NHS use through specialist tier 3/4 weight management services. However, availability and waiting times vary significantly by region and local commissioning group (ICB). Your GP can refer you to your local specialist service for assessment.
What's the healthy weight range for my height?
Use our free BMI calculator above to find your healthy weight range based on your height and current weight. The NHS recommends a BMI of 18.5–24.9 for most adults (18.5–22.9 for South Asian, Chinese, Black African, or Black Caribbean adults). A prescriber will assess whether prescription weight loss treatment is appropriate for your individual circumstances.
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.