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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Monjoro — Complete UK Health Guide
Monjoro (tirzepatide) is a prescription-only weight management injection available in the UK. This comprehensive UK health guide explains how Monjoro works, who may be eligible, what to expect from treatment, and how to access it through the NHS or private prescribing. Whether you're exploring weight management options or seeking NHS guidance, this information covers everything UK adults need to know about Monjoro treatment and the support available through your GP or specialist services.
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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 Monjoro Works and UK Eligibility
Monjoro is a dual GIP and GLP-1 receptor agonist — a different mechanism to earlier weight loss injections. It activates two natural hormone pathways that regulate appetite, helping you feel fuller after smaller meals and reducing food cravings. The medication slows gastric emptying, meaning food leaves your stomach more slowly, which can extend feelings of fullness.
UK Eligibility for Monjoro:
- BMI of 30 kg/m² or above (obese), OR
- BMI of 27–29.9 kg/m² (overweight) with at least one weight-related health condition — such as type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats, sleep apnoea, or cardiovascular disease
- For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds apply (from BMI 27.5)
- Age 18 and above; not suitable during pregnancy or breastfeeding
Your GP or a licensed prescriber will assess whether Monjoro is appropriate for your individual circumstances following a clinical assessment.
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.
Using the MyWeightCheck BMI Calculator and Getting NHS Support
If you're unsure whether you may be eligible for Monjoro, use our free BMI calculator above to check your current BMI instantly — this gives you a starting point for discussing weight management options with your GP. In the UK, prescription weight loss treatment like Monjoro is accessed through two routes: NHS specialist tier 3 or 4 weight management services (following referral from your GP, though waiting lists vary significantly by region), or through private online prescribing with a UK-licensed prescriber after clinical assessment.
Both routes require a prescription. Your GP can advise on NHS access in your area, or you can explore private options independently. Weight loss medications work most effectively alongside a reduced-calorie diet, increased physical activity, and lifestyle changes — they are tools to support, not replace, healthy habits.
Track your weight loss progress using our free progress tracker, which helps you log weekly changes and stay motivated throughout your treatment. If you have questions about whether Monjoro suits your health situation, your next step is to speak with your GP, who can refer you to specialist services or advise on private assessment options. The NHS also provides free guidance through your local weight management services on nutrition, activity, and behaviour change alongside any medication.
- 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 Monjoro available on the NHS in the UK?
Yes, Monjoro (tirzepatide) has been approved by NICE for use within NHS specialist weight management services. However, NHS access is through tier 3/4 specialist services following GP referral, and availability and waiting times vary significantly by region and ICB (Integrated Care Board). Your GP can advise on access in your area.
What is the difference between Monjoro and Wegovy?
Both are prescription-only weight management injections available in the UK. Monjoro is a dual GIP and GLP-1 receptor agonist, while Wegovy (semaglutide) is a GLP-1-only agonist. Monjoro has a higher maximum dose (15 mg) compared to Wegovy (2.4 mg). Clinical trials suggest similar average weight loss outcomes, though individual results vary significantly.
What are the common side effects of Monjoro in the UK?
Very common side effects include nausea, diarrhoea, vomiting, constipation, and stomach pain. Most side effects tend to improve over time as your body adjusts. Less common but serious effects include severe stomach pain (possible pancreatitis) or gallbladder problems. Always discuss any concerning symptoms with your GP or prescriber immediately.
How much weight can you lose with Monjoro in the UK?
Based on clinical trial data (SURMOUNT-1), average weight loss at 72 weeks ranged from approximately 15% body weight at the 5 mg dose to 21% at the maximum 15 mg dose — alongside a reduced-calorie diet and increased physical activity. Individual results vary considerably; some people lose more, some less. Your actual weight loss depends on your starting weight, adherence, diet, and activity level.
Can I use the MyWeightCheck weight converter and BMI calculator with Monjoro?
Yes — use our free weight converter to track your weight in stone, pounds, or kilograms as you progress through treatment. Our BMI calculator helps you monitor how your BMI changes over time. Our GLP-1 weight loss calculator can also estimate potential weight loss projections at different Monjoro doses, helping you understand realistic expectations for your treatment journey.
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.