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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Understanding Weight Management and Prescription Options
If you've searched for "Manjouro", you may be looking for information about prescription weight management medications available in the UK. While this exact spelling doesn't match a current licensed medication, there are several GLP-1 and dual-action weight management injections available through NHS and private prescribers. This guide explains how these prescription medications work, UK eligibility criteria, and how to access them. Understanding your options is the first step towards sustainable weight management. Use our free BMI calculator to assess where you stand health-wise, and explore the NHS guidance on weight management support available in the UK.
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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.
UK-Licensed Weight Management Medications Explained
The UK currently has three prescription-only weight management injections licensed for adults. Wegovy (semaglutide) is a once-weekly GLP-1 receptor agonist with doses ranging from 0.25 mg to 2.4 mg. In clinical trials, it helped participants lose an average of approximately 15% of their body weight — though individual results vary significantly. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, also given once weekly, with doses from 2.5 mg to 15 mg. Clinical trials showed Mounjaro helped achieve average weight losses of 15–21% of body weight. Saxenda (liraglutide) is a daily injection, a GLP-1 medication with a maximum dose of 3 mg per day. All three are prescription-only medicines requiring assessment by a licensed prescriber before use. They work alongside a reduced-calorie diet and increased physical activity — they're not replacements for lifestyle changes.
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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.
How to Access Weight Management Medication in the UK
In the UK, you can access prescription weight management medication through two routes. The NHS route requires referral to a specialist tier 3 weight management service from your GP. However, NHS availability varies significantly by region, and waiting lists can be lengthy in many areas. The private route involves an online consultation with a UK-licensed prescriber. If clinically appropriate following assessment, a prescription is issued and dispensed by a registered pharmacy. Private costs typically range from £129–£320 per month depending on medication and dose. Whichever route you choose, a proper clinical assessment is essential — these medications aren't suitable for everyone. Your GP can discuss which pathway is right for your circumstances and health profile.
- 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's the difference between Mounjaro and Wegovy?
Both are prescription-only weight management injections available in the UK, but they work differently. Mounjaro (tirzepatide) uses dual GIP and GLP-1 mechanisms and showed slightly higher average weight loss (15–21%) in trials. Wegovy (semaglutide) uses GLP-1 alone and showed average weight loss around 15%. Both are once-weekly injections. Individual results vary, and suitability depends on your personal health profile — your prescriber will assess which is appropriate for you.
Am I eligible for prescription weight loss medication on the NHS?
NHS eligibility generally requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions (such as type 2 diabetes, high blood pressure, or sleep apnoea). For South Asian, Chinese, Black African, and Black Caribbean adults, lower BMI thresholds may apply. Access is through specialist tier 3 weight management services via GP referral. Regional availability varies significantly — contact your GP to discuss options in your area.
How much weight can I expect to lose?
Clinical trials showed average weight losses of 14–21% of body weight depending on the medication and dose. However, individual results vary considerably — some people lose more, some less. Weight loss depends on the medication, adherence, diet, physical activity, genetics, and overall health. No specific outcome is assured for any individual. Your prescriber can discuss realistic expectations based on your circumstances.
Are there side effects I should know about?
Common side effects include nausea, diarrhoea, vomiting, and constipation — these often improve with time. Less common side effects include fatigue, dizziness, headache, and injection site reactions. Serious side effects are rare but include severe stomach pain (possible pancreatitis) or gallbladder issues. Always read the patient information leaflet and report any concerns to your prescriber. Most people tolerate these medications well.
How do I know if weight management medication is right for me?
Weight management medications are one tool alongside diet and exercise — not a replacement for lifestyle changes. A licensed prescriber will assess your individual health, BMI, medical history, and weight-related conditions. Use our free BMI calculator to understand your current status, then discuss your options with your GP. A proper clinical assessment is essential before any prescription is issued.
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.