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 Shot In Thigh — UK Cost & Access Guide
Mounjaro (tirzepatide) can be injected into the thigh as one of several injection sites, alongside the stomach and upper arm. If you're considering this prescription-only weight management injection in the UK, understanding how to access it — whether through the NHS or privately — and what it costs is essential. This guide covers the practical steps, cost differences, and what to expect when starting treatment.
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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.
Private Cost & Access Routes in the UK
Private prescription costs for Mounjaro in the UK typically range from £129 to £320 per month, depending on your dose and the private provider. At the 2.5 mg starting dose, costs are generally lower; at the maximum 15 mg dose, costs are higher. This includes the cost of the prescription, clinical assessment, and dispensing through a GPhC-registered online pharmacy.
The private route involves an online consultation with a UK-licensed prescriber who will assess your eligibility based on your BMI, health history, and weight-related conditions. If approved, a prescription is issued and your Mounjaro KwikPen is delivered to your home. There are no GP referrals needed. You control the pace — many people start within days rather than waiting months. Use our free GLP-1 weight loss calculator to estimate potential outcomes at different doses, which may help inform your decision.
- No NHS waiting lists
- Prescription issued within 24–48 hours if approved
- Full dose range (2.5–15 mg) available privately
- Monthly cost varies by provider and dose tier
Clinically BackedWeight Loss
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 vs Private: Route, Timeline & Eligibility
NHS access is available through specialist tier 3 weight management services following a GP referral. NICE (National Institute for Health and Care Excellence) has approved tirzepatide for NHS use, but regional variation is significant — some ICBs (Integrated Care Boards) offer it readily, whilst others have long waiting lists (sometimes 12–24 months). The NHS route is free at point of use but typically requires attendance at a specialist clinic and regular monitoring.
Eligibility criteria are similar for both routes: BMI 30 kg/m² or above, or BMI 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, dyslipidaemia, sleep apnoea). Check your personal BMI using our free BMI calculator to see where you stand. For South Asian, Chinese, Black African, or Black Caribbean adults, lower thresholds may apply. Your choice of route depends on timescale, privacy preference, and local NHS availability.
- 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.
Can I inject Mounjaro into my thigh myself?
Yes. The thigh is an approved injection site for Mounjaro. You can self-inject into the front outer thigh, rotating injection sites weekly. The KwikPen is designed for self-use, though some people prefer assistance from a partner or nurse. Your prescriber will provide injection training and written guidance.
How much does Mounjaro cost privately in the UK per month?
Private Mounjaro typically costs £129–£320 monthly depending on your dose. Starting doses (2.5–5 mg) are cheaper; higher maintenance doses (10–15 mg) cost more. Prices vary slightly between providers. Cost includes the prescription, clinical assessment, and pharmacy dispensing fee.
Is Mounjaro available on the NHS in the UK?
Yes, NICE approved tirzepatide (Mounjaro) for NHS weight management services in 2024. However, access varies significantly by region and waiting lists can be lengthy (sometimes 12–24 months). You'll need a GP referral to a specialist tier 3 weight management service. Contact your local ICB or ask your GP about availability in your area.
What's the difference between Mounjaro and Wegovy for UK access?
Both are prescription-only once-weekly injections licensed in the UK for weight management. Mounjaro is a dual GIP/GLP-1 agonist; Wegovy is a GLP-1 agonist only. Average weight loss differs slightly between trials. Both can be accessed privately or through NHS specialist services. Your prescriber will advise which is appropriate for you.
How long does it take to get Mounjaro on the NHS vs privately?
Privately, if approved, you can typically receive your first prescription within 24–48 hours. NHS timelines vary dramatically by region — some areas offer appointments within weeks, others have waiting lists of 12+ months. Private access is faster but costs money; NHS is free but involves waiting and regional variation.
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.