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 Much Does The Mounjaro Jab Cost In The UK?
The cost of Mounjaro (tirzepatide) in the UK depends on whether you access it privately or through the NHS. Private prescription costs typically range from £129 to £320 per month, depending on the dose, whilst NHS access is free but involves referral to specialist weight management services. Both routes require a valid prescription following clinical assessment. This guide covers what you can expect to pay, how to access Mounjaro, and the differences between private and NHS routes.
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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 Mounjaro Costs In The UK
Private prescription costs for Mounjaro typically range from £129 to £320 per month, depending on your dose and the provider. Each KwikPen contains 4 weekly injections (a month's supply). Costs increase with higher doses:
- 2.5 mg dose: approximately £129–£150/month
- 5 mg dose: approximately £160–£190/month
- 10 mg dose: approximately £220–£270/month
- 15 mg dose: approximately £280–£320/month
Private access is available through GPhC-registered online pharmacies following a consultation with a UK-licensed prescriber. No NHS referral is required, and pens can be dispatched within days. Individual pharmacies set their own pricing, so costs vary between providers. Prescription and medication costs are separate — expect to pay for both.
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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 And The Private Route Compared
NHS access to tirzepatide is free but involves referral to a tier 3 specialist weight management service. Your GP can refer you, though NHS availability varies significantly by region and waiting times can be lengthy — often several months or longer. Once approved, medication is dispensed free through NHS prescriptions.
The private route offers faster access without NHS referral. After an online consultation assessing your medical history and eligibility, a UK-licensed prescriber can issue a prescription if appropriate. You then collect medication from a GPhC-registered pharmacy. The entire process typically takes 1–3 weeks. Private treatment remains your responsibility — it is not transferred to NHS care.
- 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 available on the NHS in the UK?
Yes, tirzepatide (Mounjaro) is approved by NICE for use within NHS specialist weight management services. However, access requires GP referral to a tier 3 service and often involves significant waiting lists. Availability varies by region. Free prescriptions once approved.
What is the typical private cost of a Mounjaro KwikPen?
Private Mounjaro KwikPens typically cost £129–£320 per month depending on dose. Each pen contains 4 weekly injections. Costs vary between providers — compare options before ordering. The prescription fee (usually £9.65 on NHS prescription) is separate.
How long does it take to get Mounjaro privately in the UK?
Private Mounjaro access typically takes 1–3 weeks from online consultation to delivery. A UK-licensed prescriber reviews your medical history and assesses eligibility. If approved, your prescription is sent to a GPhC-registered pharmacy and dispatched. NHS routes involve longer waits.
Do I need a GP referral to get Mounjaro privately?
No. Private prescription access does not require NHS referral. You can book a consultation directly with an online pharmacy's prescriber. However, you must still have a valid clinical assessment showing you meet eligibility criteria (BMI ≥30, or ≥27 with weight-related health conditions).
Can my GP prescribe Mounjaro privately instead of NHS?
Some GPs may issue private prescriptions for Mounjaro, but this is not standard practice. Most private access routes use online pharmacies with dedicated prescribers. Your GP can still refer you to NHS specialist services, which offer free treatment if approved.
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.