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
Free tracker included with every download this week
What Is Monjo? UK Health Information
Monjo is not currently a recognised prescription weight management medication in the UK. If you've heard this term in relation to weight loss, it may be a brand name variation or newer medication not yet widely available on the NHS or private prescribing. For accurate, up-to-date information about prescription weight loss options available in the UK, including Mounjaro, Wegovy, and Saxenda, it's best to speak with your GP or a licensed healthcare professional. MyWeightCheck provides free health information tools and calculators to support your weight management journey alongside professional medical advice.
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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.
Available UK Weight Management Options
The UK currently has three prescription-only weight loss medications licensed for adult weight management:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist administered once weekly, available through NHS specialist services and private prescribing
- Wegovy (semaglutide) — a GLP-1 receptor agonist administered once weekly, approved for weight management in UK adults
- Saxenda (liraglutide) — a GLP-1 receptor agonist administered once daily, also available through NHS and private routes
All three are prescription-only medications requiring a clinical assessment from a qualified healthcare professional. NHS access is typically through tier 3 specialist weight management services, though availability and waiting times vary by region. Your GP can advise whether you may be eligible and help with a referral.
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.
Getting Started With UK Weight Management
If you're exploring weight management options in the UK, the first step is speaking with your GP, who can assess your health, discuss suitable interventions, and refer you to specialist services if appropriate. You can also use MyWeightCheck's free tools to understand your current health position: calculate your BMI using our free BMI calculator, check your healthy weight range, and use our weight converter to understand your weight in both metric and imperial measurements. For those exploring medication options, our GLP-1 weight loss calculator can help you understand potential outcomes. Remember, prescription weight loss medications work best alongside sustained lifestyle changes, including balanced nutrition and increased physical activity.
- 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 Monjo available in the UK?
Monjo is not currently a recognised prescription weight loss medication available through UK NHS services or GPhC-registered private pharmacies. If you've encountered this name, verify with your GP or a licensed healthcare provider. The UK's approved weight loss injections are Mounjaro, Wegovy, and Saxenda. Always consult a healthcare professional before starting any weight management treatment.
What weight loss medications are available on the NHS in the UK?
The NHS provides tirzepatide (Mounjaro), semaglutide (Wegovy), and liraglutide (Saxenda) through specialist tier 3 weight management services. Eligibility typically requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions. Availability and waiting times vary by region. Contact your GP for a referral to your local specialist service.
How do I check if I'm eligible for prescription weight loss treatment in the UK?
Eligibility for prescription weight loss medication in the UK generally requires a BMI of 30 or above, or 27–29.9 with conditions like type 2 diabetes, hypertension, or sleep apnoea. Use MyWeightCheck's free BMI calculator to check your current BMI, then speak with your GP about eligibility and referral to specialist services. Your GP will conduct a full health assessment.
What's the difference between NHS and private weight loss medication access?
NHS access is through specialist tier 3 services (usually involving waiting lists) and is free at point of care. Private access is via online consultations with UK-licensed prescribers and GPhC-registered pharmacies, typically available more quickly but at a cost. Both routes require a clinical assessment; your GP can advise which option suits your circumstances best.
Can I use MyWeightCheck tools to understand my weight management options?
Yes. Use our free BMI calculator to understand your current BMI category according to NHS guidelines, our weight converter to see your weight in metric and imperial measurements, and our GLP-1 weight loss calculator to explore potential outcomes with prescription medications. These tools provide educational information to discuss with your GP or healthcare professional.
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.