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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Weight Loss Food Delivery Service and Prescription Medication in the UK
Weight loss food delivery services can support your weight management journey, but for many people, prescription medication combined with dietary changes offers the most effective results. In the UK, several prescription options are available for eligible adults who want to lose weight — either through the NHS or private prescribing. This guide explains how weight loss injections work alongside food choices, who qualifies, and how to access treatment through your GP or online.
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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 and Eligibility
Three main prescription weight loss medications are licensed in the UK for weight management:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist injected once weekly, which may help reduce appetite and support feeling fuller after meals
- Wegovy (semaglutide) — a GLP-1 receptor agonist, also once weekly, with clinical trial data showing average weight loss of around 15% body weight
- Saxenda (liraglutide) — a daily GLP-1 injection alternative for those who prefer more frequent dosing
To be eligible for prescription weight loss medication in the UK, you typically need a BMI of 30 or above, or 27 or above if you have weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. Try our free BMI calculator to check where you stand. 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. Clinical trials have shown these medications may help participants lose 15–21% of their body weight when combined with dietary changes and increased physical activity — though individual results vary significantly.
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 How to Start
NHS access typically requires referral to a specialist tier 3 weight management service from your GP. Waiting times vary by region and can be lengthy in some areas. Private access is available through UK-licensed online prescribing services — no NHS referral needed — following a clinical assessment. Food delivery services work best when paired with professional weight loss support; your prescriber or GP can advise how to combine them effectively. Start by booking a GP appointment to discuss your weight loss goals and whether prescription medication is appropriate for you. Your GP can assess your eligibility, review your health history, and either refer you to NHS specialist services or advise on private options. Using our free GLP-1 weight loss calculator, you can estimate potential weight loss at different medication doses to help inform your conversation with your healthcare provider.
- 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 a food delivery service instead of taking prescription weight loss medication?
Food delivery services can support weight loss by providing portion-controlled, nutritionally balanced meals. However, prescription GLP-1 medications like Mounjaro or Wegovy work through appetite suppression and may offer greater results for eligible adults. Many people combine both approaches — using medication alongside a structured diet for best outcomes. Your GP can advise what's right for you.
How much weight can I expect to lose with prescription weight loss 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. Weight loss depends on your starting weight, medication dose, adherence, diet, and physical activity. Use our weight loss calculator to see projected results at different doses.
Am I eligible for weight loss medication on the NHS in the UK?
NHS eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions. You'll need a GP referral to a specialist weight management service. Availability varies by region. Book a GP appointment to check your eligibility and discuss options.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist showing slightly higher average weight loss (up to 21%) compared to Wegovy (around 15%). Both are once-weekly injections. Mounjaro has a higher starting dose, while Wegovy starts lower and escalates gradually. Your prescriber will recommend the best option based on your health profile.
How quickly can I get prescription weight loss medication privately in the UK?
Private online prescribing can be faster than NHS waiting lists — you may receive a prescription within days following a brief online clinical assessment. However, you'll need to meet clinical eligibility criteria and the cost (typically £129–£320 monthly depending on dose) is not covered by the NHS. Private treatment is subject to the same prescription requirements as NHS 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.