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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Cheapest 7.5 Mounjaro UK — Cost and Comparison Guide
Finding affordable Mounjaro 7.5 mg in the UK involves understanding both prescription routes and how this dose compares to alternatives like Wegovy. The 7.5 mg dose is an escalation step in Mounjaro treatment, typically reached at around weeks 9–12 of therapy. Cost varies significantly between NHS access through specialist weight management services and private prescription options. Both Mounjaro and Wegovy require a clinical assessment before prescription, and individual suitability depends on your health profile rather than price alone. This guide explains the cost context, clinical trial data, and how these two weight loss injections compare.
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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.
Clinical Trial Results and Mechanism Differences
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, meaning it activates two natural hormone pathways. In the SURMOUNT-1 clinical trial, participants on the 10 mg dose (a higher escalation than 7.5 mg) achieved an average weight loss of approximately 19.5% of their body weight over 72 weeks. The 7.5 mg dose, as an intermediate escalation, typically produces results between the 5 mg and 10 mg outcomes.
- SURMOUNT trial: Average 15–clinically studied weight loss depending on final dose achieved
- Mechanism: Dual action on appetite regulation and glucose control
- Injection frequency: Once weekly
Wegovy (semaglutide) is a single GLP-1 receptor agonist. The STEP-1 clinical trial showed approximately 14.9% average weight loss at the maximum dose of 2.4 mg over 68 weeks. Wegovy reaches its highest dose (2.4 mg) later in the treatment timeline than Mounjaro reaches 15 mg.
- STEP trial: Average clinically studied weight loss at maximum dose
- Mechanism: Single GLP-1 pathway activation
- Injection frequency: Once weekly
Clinical trial results show both medications are effective, but average outcomes differ slightly. Individual results vary considerably and depend on adherence, lifestyle changes, and personal physiology.
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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 Cost Comparison and Suitability Factors
In the UK, both Mounjaro and Wegovy are available through NHS specialist weight management services or private prescription. Private costs vary by dose and provider: Mounjaro 7.5 mg typically ranges from £180–£240 per month, while Wegovy at equivalent stages ranges from £130–£200 per month. However, prices change frequently and vary between GPhC-registered pharmacies.
Choosing between them is not primarily a cost decision — it's a clinical one. Your prescriber assesses which medication suits your individual health profile, medical history, and any contraindications. Some people respond better to the dual mechanism of Mounjaro; others find Wegovy equally effective. Both require a prescription and clinical assessment. Use our GLP-1 weight loss calculator to explore projected outcomes at different doses, and consult your GP or a licensed prescriber about which option may be appropriate for you.
- 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 7.5 mg cheaper than Wegovy in the UK?
Private pricing varies by pharmacy and dose, but Mounjaro 7.5 mg is often comparable to or slightly more expensive than Wegovy at similar treatment stages. Prices range from £180–£240 monthly for Mounjaro vs £130–£200 for Wegovy, though costs vary. NHS access is free but involves specialist referral and waiting times.
What is the difference between Mounjaro and Wegovy mechanisms?
Mounjaro is a dual GIP+GLP-1 receptor agonist activating two hormone pathways, while Wegovy is a GLP-1 agonist only. This dual mechanism is why Mounjaro may achieve slightly higher average weight loss in clinical trials, but individual responses vary significantly.
How quickly does Mounjaro 7.5 mg reach its dose?
Mounjaro 7.5 mg is typically reached around weeks 9–12 of treatment, following a titration schedule starting at 2.5 mg. The dose increases by 2.5 mg every 4 weeks. Your prescriber manages the timing based on your tolerance and response.
Can I switch between Mounjaro and Wegovy in the UK?
Switching between medications is a clinical decision made by your prescriber, not a patient choice. There is no official conversion formula. Any switch must be managed by a licensed healthcare professional who assesses your suitability for the alternative medication.
Do I need a prescription for both Mounjaro and Wegovy in the UK?
Yes, both are prescription-only medicines requiring a clinical assessment. You cannot access either without a prescription from a UK-licensed prescriber, whether through NHS specialist services or private online prescription options.
Ready to take control of your weight loss journey?
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