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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How to Maintain on Mounjaro: UK Cost and Access
Maintaining Mounjaro treatment in the UK involves understanding both the ongoing costs and how to access your prescription reliably. Whether you're considering this tirzepatide injection through the NHS or private routes, knowing what to expect helps you plan ahead. This guide explains UK prescription pathways, typical costs at different maintenance doses, and practical steps to keep your treatment consistent.
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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.
UK Private Prescription Costs and Maintenance Doses
Mounjaro (tirzepatide) maintenance typically occurs at doses between 5 mg and 15 mg once weekly, depending on your individual response. Private UK prescriptions for Mounjaro generally range from £129 to £320 per month, depending on your maintenance dose and the provider.
- 5 mg dose: Around £129–£150/month (lower maintenance tier)
- 10 mg dose: Around £180–£220/month (mid-range maintenance)
- 15 mg dose: Around £280–£320/month (maximum maintenance dose)
Each KwikPen contains four once-weekly injections, so one pen lasts approximately four weeks. When choosing to maintain on Mounjaro privately, budget for ongoing monthly costs and factor in the clinical assessment fee (typically £20–£50) required for your initial prescription and periodic reviews. Most private providers require reassessment every 3–6 months to check your progress and confirm suitability.
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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 vs Private Access: Finding Your Maintenance Route
Accessing Mounjaro on the NHS requires referral to a tier 3 specialist weight management service through your GP, though availability varies significantly by region and NHS ICB (Integrated Care Board). NHS access is free but waiting lists can be lengthy—sometimes 6–12 months or longer depending on your area. Private access via a UK-licensed prescriber and GPhC-registered pharmacy is faster and doesn't require NHS referral, but you cover the full prescription cost.
For maintenance, NHS patients typically attend clinic appointments every 3–6 months for dose reviews and health monitoring. Private patients can usually arrange follow-up consultations and prescription renewals online, making maintenance more flexible. Many people transition between routes—starting private for quicker access, or moving to NHS once eligible and available. Whichever route you choose, consistent GP engagement helps your primary care team monitor your overall health alongside Mounjaro treatment.
- 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 does a Mounjaro KwikPen cost on private prescription in the UK?
Private prescription costs in the UK typically range from £129 to £320 per month depending on your maintenance dose (5 mg to 15 mg). Each KwikPen contains four once-weekly injections and lasts about four weeks. Prices vary between providers, so it's worth checking a few licensed pharmacies for the best rate at your dose.
Can I get Mounjaro on the NHS for weight management?
Yes—Mounjaro (tirzepatide) is now NICE-approved for NHS use in specialist weight management services. You'll need referral from your GP to tier 3 services in your area. NHS access is free, but waiting lists vary significantly by region, sometimes taking 6–12 months or longer. Private access is faster but costs apply.
How often do I need GP appointments to maintain on Mounjaro?
NHS maintenance typically involves clinic reviews every 3–6 months to assess progress, manage side effects, and adjust doses if needed. Private patients often have flexibility to arrange online consultations and prescription renewals, though most providers recommend check-ins every 3–6 months as well. Regular GP engagement is important for overall health monitoring.
What's the difference between maintaining on Mounjaro vs Wegovy for ongoing costs?
Both are once-weekly injections with similar UK private costs (roughly £129–£320/month depending on dose). Mounjaro doses go up to 15 mg weekly, while Wegovy's maximum is 2.4 mg. Mounjaro is a dual GIP/GLP-1 agonist, Wegovy is GLP-1-only. Maintenance costs depend more on your actual dose than the medication itself.
How can I track my progress while maintaining on Mounjaro?
Use our free GLP-1 weight loss calculator to estimate your weight loss trajectory and monitor expected progress at your current dose. Our free progress tracker helps you log weekly weights and see trends over time. Combined with regular prescriber reviews, these tools help you and your GP assess whether your current maintenance dose is working effectively.
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.