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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Vegetarian Weight Loss Plan: Prescription Medication Options in the UK
A vegetarian weight loss plan focuses on plant-based nutrition alongside lifestyle changes. In the UK, prescription weight management medications are available for eligible adults to support these efforts. Whether you're following a vegetarian diet or any other approach, understanding your BMI and exploring available medication options can help you achieve sustainable weight loss. This guide covers UK-licensed prescription options, eligibility criteria, and how to access support through the NHS or privately.
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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 Weight Loss Medications for Your Weight Management Plan
Three prescription-only weight loss medications are currently licensed in the UK for adults managing excess weight:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist injected once weekly. Clinical trials showed participants lost an average of 15–21% of body weight over 72 weeks.
- Wegovy (semaglutide) — a GLP-1 receptor agonist injected once weekly. The STEP trial demonstrated average weight loss of approximately 15% of body weight at 68 weeks.
- Saxenda (liraglutide) — a GLP-1 receptor agonist injected daily, with similar efficacy to Wegovy.
All three work by helping regulate appetite and supporting feeling fuller after smaller meals. They are prescription-only and require a clinical assessment before being prescribed. Individual results vary significantly, and these medications are most effective when combined with dietary changes and increased physical activity — making them an excellent complement to a vegetarian weight loss plan.
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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.
NHS vs Private Access and Eligibility in the UK
You may be eligible for prescription weight loss medication in the UK if you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions (such as type 2 diabetes, high blood pressure, or cardiovascular disease). Use our free BMI calculator above to check where you stand. NHS access is through specialist tier 3 weight management services and involves a GP referral, though waiting lists vary significantly by region. Private access is available through online consultations with UK-licensed prescribers without an NHS referral. Your GP can advise on NHS eligibility and referral, or you can explore private options independently. Either way, a qualified prescriber will assess whether medication is suitable for your individual health and weight loss 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.
Can I use prescription weight loss medication as a vegetarian?
Yes. Mounjaro, Wegovy, and Saxenda are suitable for vegetarians. These medications support appetite regulation and work alongside any dietary approach, including vegetarian diets. Your prescriber will review your individual health to confirm suitability.
How does prescription weight loss medication support a vegetarian diet plan?
These medications help reduce hunger and cravings, making it easier to stick to your dietary choices. They don't restrict what you eat — they help you feel satisfied with smaller portions. Combined with a balanced vegetarian diet and physical activity, they can enhance weight loss results.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist with average weight loss of 15–21%. Wegovy (semaglutide) is a GLP-1 agonist with average weight loss around 15%. Both are once-weekly injections. Clinical evidence suggests Mounjaro may offer slightly greater average weight loss, but individual results vary considerably.
How do I find out if I'm eligible for prescription weight loss medication on the NHS?
Contact your GP and discuss your weight and health goals. They can assess your BMI and any weight-related conditions, then refer you to a specialist tier 3 weight management service if appropriate. Use our BMI calculator on this page to check your starting point.
Can I track my weight loss progress while using medication?
Yes. Our free progress tracker on this page lets you log your weight weekly and visualise your progress over time. Tracking alongside medication and dietary changes helps you stay motivated and identify patterns in your weight management 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.