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
Meatless Diet Weight Loss and UK Prescription Options
A meatless or vegetarian diet can support weight loss when combined with a calorie deficit, but some people find maintaining weight loss challenging. If you're struggling with weight management in the UK, prescription medications are available for eligible adults alongside dietary changes. This guide covers UK-licensed weight loss options, eligibility criteria, and how to access NHS and private support for sustainable weight loss.
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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 Available
Three prescription-only weight management injections are currently licensed in the UK: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These medications work by activating natural appetite-regulating hormones and may help you feel fuller after smaller meals.
Eligibility criteria: Adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea, or cardiovascular disease), may be eligible. For South Asian, Chinese, Black African, or Black Caribbean adults, lower thresholds apply due to higher health risks at lower BMI levels.
In clinical trials, these medications helped participants lose an average of 15–21% of their body weight alongside reduced-calorie diets and increased physical activity. However, individual results vary significantly. Calculate your BMI using our free BMI calculator above to see where you fall and discuss eligibility with your GP.
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.
Accessing Weight Loss Medication: NHS and Private Routes
NHS access: GLP-1 weight loss injections are available through specialist tier 3 weight management services. You'll need a GP referral, and availability varies significantly across regions. Waiting lists can be lengthy in many areas. Your GP can advise whether you meet local NHS criteria and arrange an assessment if appropriate.
Private access: GLP-1 medications are available through UK-licensed online prescribers following a clinical assessment. This route doesn't require NHS referral and is available without waiting lists, though costs apply (typically £129–£320+ per month depending on dose).
Whether you choose a meatless diet approach, prescription medication, or both, our GLP-1 weight loss calculator can help you understand potential outcomes at different doses. Talk to your GP about what's right for your circumstances.
- 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 a meatless diet alone lead to significant weight loss?
Yes, a meatless or vegetarian diet can support weight loss if it creates a calorie deficit. However, many people find they need additional support like increased activity or, in some cases, prescription medication to achieve and maintain their weight loss goals. A balanced, nutrient-dense plant-based diet is key.
Am I eligible for prescription weight loss medication in the UK?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes, high blood pressure, or cardiovascular disease. South Asian, Chinese, Black African, or Black Caribbean adults have lower eligibility thresholds. Your GP or a licensed prescriber can assess your individual eligibility following a clinical consultation.
How much weight can I expect to lose with GLP-1 medication?
Clinical trials show average weight loss of 15–21% of body weight with prescription GLP-1 medications, typically over 12–18 months, alongside dietary changes and physical activity. However, individual results vary significantly — some people lose more, some less. Results depend on dose, adherence, diet, activity level, and personal factors.
What's the difference between NHS and private weight loss medication access?
NHS access is through specialist weight management services requiring a GP referral, though waiting lists can be lengthy. Private access is available through UK-licensed online prescribers without NHS referral, with faster availability but out-of-pocket costs. Both routes require clinical assessment and prescription. Speak with your GP about which option suits you best.
Can I combine a meatless diet with GLP-1 weight loss medication?
Yes, many people successfully combine dietary approaches like vegetarian eating with prescription weight loss medication. GLP-1 medications work best alongside a reduced-calorie diet and increased physical activity. Your prescriber or a dietitian can help you plan a balanced, sustainable meatless eating pattern that works with your medication.
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.