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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Great Weight Loss Meals and Prescription Support in the UK
Eating well is essential for sustainable weight loss, but for many UK adults, dietary changes alone aren't enough. This guide covers how to build great weight loss meals alongside prescription weight management options now available in the UK. If you're carrying excess weight and struggling with diet alone, prescription medications like Mounjaro and Wegovy may be eligible options worth exploring with your GP. We'll explain what's available, who qualifies, and how to find out if treatment is right for you.
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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.
UK-Licensed Prescription Weight Management Options
Three prescription medications are now licensed in the UK for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These work alongside a reduced-calorie diet and increased physical activity — not instead of them. Mounjaro is a dual GIP and GLP-1 receptor agonist, meaning it activates two hormone pathways to help reduce appetite and support feeling fuller after smaller meals. In clinical trials, Mounjaro helped participants lose an average of 15–21% of their body weight over 72 weeks. Wegovy is a GLP-1 agonist (single mechanism) with similar effectiveness — clinical evidence showed approximately 15% average weight loss. Both are once-weekly injections, prescription-only, and require a clinical assessment before prescribing. Eligibility typically includes adults with a BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions like type 2 diabetes, high blood pressure, or cardiovascular disease. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply due to higher health risks at lower weights.
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 and Next Steps
NHS access is through specialist tier 3 weight management services — your GP can refer you, though waiting lists vary by region and can be several months. Private access is available through GPhC-registered online clinics following a consultation with a UK-licensed prescriber; this is faster but involves a cost (typically £150–£300+ per month depending on dose). Alongside any medication, great weight loss meals should include plenty of vegetables, lean proteins, whole grains, and healthy fats. Use our free GLP-1 weight loss calculator to estimate potential weight loss at different medication doses. Your first step is a conversation with your GP about whether prescription weight management is appropriate for your individual health. They can discuss your BMI, any weight-related health conditions, and whether referral to specialist services or private treatment might help you reach your goals.
- 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 counts as a great weight loss meal?
Great weight loss meals are high in protein and fibre (keeping you fuller longer), lower in calories, and nutrient-dense. Examples: grilled chicken with broccoli and brown rice, lentil soup with wholemeal bread, salmon with roasted vegetables, Greek yogurt with berries. Aim for meals around 400–600 calories with at least 25g protein. Avoid highly processed foods, sugary drinks, and excessive oils.
Can I take prescription weight loss medication without changing my diet?
No. Mounjaro, Wegovy, and Saxenda are prescribed alongside a reduced-calorie diet and increased physical activity — they're not replacements for lifestyle change. Medications work best when combined with healthier eating habits and regular exercise. Your prescriber will advise on diet and activity targets during your consultation.
How do I know if I'm eligible for prescription weight loss treatment in the UK?
General eligibility includes a BMI of 30 or above, or 25–29.9 with weight-related health conditions. However, criteria vary by region and individual circumstances. Your GP can assess your eligibility and discuss whether referral to NHS specialist services or private treatment is appropriate. Some adults also qualify through private clinics without NHS referral.
What's the difference between NHS and private weight loss medication in the UK?
NHS prescriptions are through specialist weight management services (free but often with waiting lists of months). Private prescriptions are available through online clinics (faster access, typically £150–£300+ monthly cost). Both require a clinical assessment; the medication itself is identical. Private routes don't require NHS referral.
How much weight could I realistically lose with prescription medication?
Clinical trials show average weight loss of 15–21% of body weight with Mounjaro and around 15% with Wegovy over 12–18 months — but individual results vary significantly. These figures are achieved alongside dietary changes and increased activity. Your actual outcome depends on dose, adherence, lifestyle changes, and individual metabolism. Use our weight loss calculator for personalised projections.
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.