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 Click Chart — UK Access and Costs Explained
A Mounjaro click chart shows the progressive dose increases from the starting 2.5 mg injection through to the maximum 15 mg weekly maintenance dose. Understanding the click chart helps you plan costs and timelines when considering this prescription-only weight management injection. This guide covers NHS access, private prescription costs in the UK, and what the titration process involves.
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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 for Tirzepatide
The cost of Mounjaro through private UK prescription routes varies by provider and dose. Starting doses (2.5 mg) typically cost between £129–£170 for a 4-week supply (one KwikPen containing four injections). Maintenance doses (5–10 mg) generally range from £150–£220, while the maximum 15 mg dose can cost £200–£280 per month depending on the provider.
Each KwikPen contains exactly four weekly doses, so costs are roughly per 4-week cycle. Private online prescribers require a clinical assessment consultation (often £15–£40) before issuing a prescription. Unlike NHS services, private routes offer faster access without waiting lists, though costs are higher than NHS provision where available. Always compare providers, as pricing and consultation fees vary significantly across GPhC-registered online pharmacies.
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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 Routes
NHS access: Mounjaro (tirzepatide) is approved by NICE for use through specialist tier 3 and tier 4 weight management services. You need a GP referral and assessment by a specialist team — availability and waiting times vary significantly by region. When prescribed through the NHS, there is no cost beyond your standard prescription charge (currently £9.90 in England, or free if exempt).
Private access: Available immediately through online clinical consultations with UK-licensed prescribers. No NHS referral needed. You complete a health questionnaire, speak with a prescriber, and receive a prescription if suitable. Dispensed by GPhC-registered pharmacies. Faster but costs £129–£280+ monthly depending on dose. Both routes require a prescription and clinical assessment — neither provides medication without professional evaluation.
- 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.
How does the Mounjaro click chart work?
The click chart refers to the KwikPen dose dial. Each weekly injection advances the pen's click mechanism to deliver the next scheduled dose: weeks 1–4 deliver 2.5 mg, weeks 5–8 deliver 5 mg, continuing upward in 2.5 mg increments every 4 weeks until reaching the maximum 15 mg. Each pen contains four clicks (four weeks of doses). You rotate to a new pen every 4 weeks.
What is the total cost of a full Mounjaro treatment course in the UK?
This varies widely. Private costs range from roughly £500–£1,000+ monthly depending on your current dose. Since treatment duration varies (some continue long-term, others stop after reaching their weight loss goal), total costs are individual. NHS costs are just your standard prescription charge per item where available. Discuss expected duration and cost with your prescriber.
Is Mounjaro cheaper on the NHS than private prescription?
Yes, significantly. NHS prescriptions cost £9.90 per item in England (or free if exempt), versus £129–£280+ monthly privately. However, NHS access requires referral to specialist weight management services with variable waiting times. Private routes offer immediate access but at higher cost. Both require a prescription and clinical assessment.
How long does a single Mounjaro KwikPen last?
One KwikPen contains exactly four weeks of doses (four clicks). At the starting 2.5 mg dose, one pen lasts 4 weeks. As you titrate up, each successive pen still contains four weeks of your new dose. You'll need a new prescription every 4 weeks, or roughly 13 pens per year if continuing treatment.
Can I switch between NHS and private Mounjaro prescriptions?
Switching routes requires discussion with your healthcare provider. If you start on NHS and wish to move to private (or vice versa), you'll need a new prescription from the appropriate route's prescriber. NHS GPs cannot "convert" to private prescriptions directly — you'd need a new clinical assessment from a private prescriber. Always inform any new provider of your previous treatment history.
Ready to take control of your weight loss journey?
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