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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Halal Meal Prep and Weight Loss Medication in the UK
Halal meal prep is a practical approach to weight management that aligns with dietary values, but for many adults in the UK, combining structured meal preparation with prescription weight loss medication may offer more effective results. If you're considering weight management options, understanding both lifestyle strategies and medical support available through the NHS or private prescription can help you make informed choices. Our free GLP-1 weight loss calculator can help you estimate potential outcomes with medication support, whilst our BMI calculator shows where you stand relative to NHS weight guidelines.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
Prescription Weight Loss Medication Available in the UK
Three prescription-only weight loss medications are currently licensed in the UK for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These are GLP-1 receptor agonists (or in Mounjaro's case, a dual GIP/GLP-1 agonist) that may help reduce appetite and support feeling fuller after smaller meals when combined with a reduced-calorie diet and increased physical activity.
Clinical evidence shows average weight loss of 15–21% body weight with Mounjaro and around 15% with Wegovy over 12–18 months in trials, though individual results vary significantly. Saxenda is a daily injection, whilst Mounjaro and Wegovy are once-weekly injections. All three require a prescription from a licensed prescriber following a clinical assessment to confirm you're eligible and it's safe for you.
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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 Finding Out If You're Eligible
NHS access: Available through specialist tier 3 weight management services following a GP referral. Availability varies significantly by region and waiting lists can be lengthy. Private access: Available through GPhC-registered online pharmacies with a prescription from a UK-licensed prescriber, without NHS referral.
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, heart disease, sleep apnoea). Use our free BMI calculator to check your current BMI. The next step is speaking with your GP about your eligibility and discussing whether prescription weight loss support alongside your halal meal prep approach would be appropriate 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 I use halal meal prep with weight loss medication?
Yes. Prescription weight loss medications like Mounjaro and Wegovy work alongside dietary changes, including halal meal prep. In fact, medication is most effective when combined with a structured reduced-calorie diet and increased physical activity. Your prescriber can discuss how to integrate both approaches safely.
How do I know if I'm eligible for prescription weight loss medication in the UK?
Eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes or high blood pressure. Use our free BMI calculator to check your BMI, then speak with your GP about eligibility and whether medication would be appropriate for you personally.
What's the difference between Mounjaro, Wegovy, and Saxenda?
All three are prescription-only weight loss medications. Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist with doses up to 15mg weekly. Wegovy (semaglutide) is a GLP-1 agonist with doses up to 2.4mg weekly. Saxenda (liraglutide) is a GLP-1 agonist requiring daily injections. Clinical trials show similar average weight loss (15–21%), but individual results vary. Your prescriber will recommend the most suitable option.
Can I get prescription weight loss medication through the NHS?
Yes, through specialist tier 3 weight management services accessed via GP referral. However, NHS availability varies significantly by region and waiting lists can be several months or longer. Private prescription is also available and may be quicker, though involves out-of-pocket costs.
How much weight can I expect to lose with medication?
Clinical trials show average weight loss of 15–21% body weight over 12–18 months with Mounjaro and around 15% with Wegovy, but individual results vary considerably. Weight loss depends on your starting weight, adherence to reduced-calorie diet, physical activity, and how your body responds. Your prescriber can discuss realistic expectations for your situation.
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.