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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What Is Mounjaro For — Accessing Weight Management in the UK
Mounjaro (tirzepatide) is a prescription-only injection licensed in the UK for weight management in adults with obesity or overweight with weight-related health conditions. It's a dual GIP and GLP-1 receptor agonist that may help reduce appetite and support weight loss alongside diet and physical activity. Understanding what Mounjaro is for—and how to access it—involves knowing both NHS and private routes, costs, and eligibility criteria. This guide explains your options in clear, practical terms.
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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.
How Much Does Mounjaro Cost 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 provider. The Mounjaro KwikPen comes in different strengths (2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg), and each pen contains four doses—one month's supply if you're injecting weekly.
- Starting doses (2.5–5 mg): Often cheaper at £129–£180/month
- Maintenance doses (10–15 mg): Usually £220–£320/month
- Online consultations: Typically £20–£50 additional fee
- NHS cost: Prescription charges apply if eligible (currently £9.90 per item in England)
Costs vary between providers, so comparing options is worth doing. Many people budget for ongoing treatment, as Mounjaro is typically continued long-term if weight loss is maintained.
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 Access — Which Route Is Right for You?
NHS route: Mounjaro is available through specialist tier 3 weight management services, but access is limited and regional variation is significant. You'll need a GP referral, a specialist assessment, and may face waiting lists of several months. Once approved, you pay only the standard prescription charge (£9.90 in England).
Private route: You can obtain Mounjaro through a UK-licensed online prescriber following a remote consultation. No NHS referral needed—faster access, but you pay the full cost. The online consultation assesses your medical history, BMI, and weight-related health conditions to confirm eligibility.
Private access suits those who don't meet NHS criteria, prefer faster access, or are waiting for NHS services. Try our free GLP-1 weight loss calculator to explore potential outcomes at different doses.
- 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 is Mounjaro used for exactly?
Mounjaro (tirzepatide) is used for weight management in UK adults with a BMI of 30 or above, or 27–29.9 with weight-related conditions like type 2 diabetes, high blood pressure, or cardiovascular disease. It's a dual GIP/GLP-1 receptor agonist injection that works alongside diet and physical activity to help reduce appetite and support sustainable weight loss.
How do I get Mounjaro on the NHS in the UK?
Ask your GP for a referral to your regional tier 3 specialist weight management service. You'll undergo a clinical assessment to confirm eligibility. Availability varies significantly by area, and waiting lists can be lengthy. Once approved and started, you'll pay only the standard prescription charge (£9.90 per pen in England).
Can I get Mounjaro privately without waiting for NHS?
Yes. You can obtain Mounjaro through a UK-licensed online prescriber following a remote consultation. The prescriber assesses your medical history and eligibility, issues a prescription if appropriate, and a GPhC-registered pharmacy dispenses it. Private costs range from £129–£320/month depending on dose, plus a consultation fee.
Is Mounjaro the same as Wegovy?
No. Both are GLP-1/GIP medications for weight management, but Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist, whilst Wegovy (semaglutide) is a GLP-1-only agonist. Mounjaro typically starts at 2.5 mg and goes up to 15 mg weekly; Wegovy starts at 0.25 mg and reaches 2.4 mg. Clinical trials showed slightly different average weight loss outcomes for each.
What happens after I start Mounjaro—how long does treatment last?
Mounjaro is typically continued long-term if you're losing weight and tolerating it well. Treatment isn't time-limited, but your prescriber will review progress regularly. If you stop Mounjaro, weight often returns, so ongoing use alongside lifestyle changes is usually necessary. Your GP or prescriber will monitor your response and manage any side effects.
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.