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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Weight Loss Jabs: Mounjaro Cost and How to Access in the UK
Mounjaro (tirzepatide) is a prescription weight loss injection available in the UK through both NHS specialist services and private prescribing routes. If you're considering this weekly weight loss injection, understanding your options and costs is essential. Access varies significantly depending on whether you go through the NHS or pursue private prescription. This guide explains how to get Mounjaro in the UK, what it costs, and what the process involves so you can make an informed decision about your weight management options.
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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.
Private Access and Cost for Mounjaro in the UK
In the UK, Mounjaro is available privately through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. Private costs typically range from £129 to £320 per month, depending on your dose and the provider — starting doses are usually cheaper, while the maximum 15mg weekly weight loss injection costs more.
A standard KwikPen contains four weeks' supply (four pre-filled pens for once-weekly injections). You'll need an online consultation where a prescriber assesses your health, BMI, and medical history to determine if Mounjaro is suitable. This consultation usually costs £15–£45 and is separate from the medication cost. Once prescribed, your KwikPen arrives at your home address, and you can self-inject weekly following straightforward instructions.
- Starting dose (2.5mg): approximately £129–£160 per month
- Maintenance dose (5–10mg): approximately £160–£240 per month
- Maximum dose (15mg): approximately £280–£320 per month
Private access means no NHS waiting list — you can start treatment within days of your prescription being approved. However, costs add up significantly over time, particularly if you remain on higher doses for extended periods.
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No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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 Access vs Private: Which Route is Right for You?
NHS access to Mounjaro is through tier 3 or tier 4 specialist weight management services, typically following a GP referral. NICE has approved tirzepatide for NHS use, but availability varies dramatically by region — some areas have no current provision, whilst others have lengthy waiting lists. If available locally, you pay nothing through the NHS, but you may wait months or years for an appointment.
The online consultation process for private prescription is straightforward: you complete a health questionnaire, have a video or telephone call with a prescriber, and if approved, your prescription is sent electronically to a pharmacy. The prescriber will assess your BMI, weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea), current medications, and contraindications. This entire process typically takes 24–48 hours. You'll receive your KwikPen with instructions and support materials, plus access to online guidance on injection technique, storage, and managing side effects.
- 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's the difference between Mounjaro and Wegovy for weight loss in the UK?
Both are prescription weekly weight loss injections, but Mounjaro (tirzepatide) is a dual GIP+GLP-1 receptor agonist, whilst Wegovy (semaglutide) is a GLP-1 agonist only. Mounjaro may achieve slightly higher average weight loss in clinical trials. Both are available privately in the UK; NHS access depends on your region. Costs and dosing schedules differ — your prescriber will advise which suits you.
Do I need a GP referral to get Mounjaro privately in the UK?
No. Private online prescribing routes do not require an NHS GP referral. You book an online consultation directly with a UK-licensed prescriber, complete a health questionnaire, and if approved, receive your prescription. However, always inform your GP that you're taking Mounjaro, as it may interact with other medications you're on.
How long does it take to get Mounjaro on the NHS in the UK?
This varies significantly by region. Some NHS areas have no tier 3 weight management services; others have waiting lists of 6–24 months or longer. Availability depends on your local ICB (Integrated Care Board) and commissioning decisions. Contact your GP to ask about referral pathways and current waiting times in your area.
Is Mounjaro available on prescription through my GP directly?
In most cases, no. GPs cannot prescribe Mounjaro directly on the NHS — it must go through specialist tier 3 weight management services. GPs can refer you, but availability is limited. Privately, you access prescription through online consultations with authorised prescribers, not through your GP surgery.
Can I use our weight loss calculator to estimate my potential results with Mounjaro?
Yes. MyWeightCheck's free GLP-1 weight loss calculator helps you project potential weight loss at different doses based on clinical trial data. Remember, actual results vary — the calculator shows averages. You can also use our BMI calculator to establish your current starting point before beginning treatment.
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.