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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Diet Plan Weight Loss Chart — UK Medication Options
A diet plan combined with a weight loss chart helps you track progress and stay motivated, but for many people in the UK, prescription weight management medication can provide additional support. If you're struggling with weight management, you may be eligible for licensed medications like Mounjaro or Wegovy on the NHS or through private prescription. This guide explains your options, how to use a weight loss chart effectively, and what prescription weight loss options are available to eligible UK adults.
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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 Loss Medications
Three prescription weight loss medications are currently licensed in the UK for eligible adults:
- Mounjaro (tirzepatide) — A dual GIP and GLP-1 receptor agonist, injected once weekly. In clinical trials, participants lost an average of 15–21% of their body weight alongside diet and exercise.
- Wegovy (semaglutide) — A GLP-1 receptor agonist, injected once weekly. Clinical evidence shows average weight loss of around 15% of body weight.
- Saxenda (liraglutide) — A daily GLP-1 injection, offering more modest weight loss than weekly injections but may suit some individuals.
You may be eligible for GLP-1 weight loss medication if you have a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply. Use our free GLP-1 weight loss calculator to see projected outcomes at different doses, and our BMI calculator to check your current classification.
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 Access vs Private Prescription — And How to Start
NHS route: Weight loss medication through the NHS is available via specialist tier 3 weight management services. Your GP can refer you, but availability and waiting times vary significantly by region. Some areas have lengthy waiting lists.
Private route: You can access prescription weight loss medication privately through a UK-licensed online prescriber without an NHS referral. A clinical assessment is still required to confirm eligibility.
Whichever route you choose, prescription medications work best alongside a structured diet plan and increased physical activity. Track your weight loss progress using our free progress tracker to monitor real results over time. If you're unsure whether you're eligible, start by calculating your BMI and discussing options with your GP — they can advise on both NHS and private pathways available to you.
- 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 is the best diet plan for weight loss?
The best diet plan is one you can sustain long-term. Evidence supports Mediterranean, low-carbohydrate, and calorie-deficit approaches. The NHS recommends losing 0.5–1 kg per week. Consistency matters more than extreme restriction. Prescription weight loss medication can support diet efforts for eligible adults.
How do I use a weight loss chart effectively?
A weight loss chart should track weekly or fortnightly weigh-ins, not daily fluctuations. Use consistent measurement times (e.g., same day, same time, same scales). Our free progress tracker lets you log weight and visualise trends over weeks and months, helping you stay motivated.
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 or above with weight-related health conditions like type 2 diabetes or high blood pressure. For South Asian or Black African heritage, lower thresholds apply. Use our BMI calculator to check your status, then discuss options with your GP.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP+GLP-1 medication with average weight loss of 15–21% in trials. Wegovy (semaglutide) is a GLP-1 medication with average weight loss around 15%. Both are once-weekly injections. Mounjaro may offer slightly greater weight loss, but individual results vary. Your prescriber will advise which suits you.
Can I get weight loss medication through the NHS?
Yes, Mounjaro and Wegovy are available through NHS specialist weight management services (tier 3). Access requires a GP referral and varies by region — waiting times can be several months. Private prescription is also available without NHS referral. Either way, a clinical assessment confirms you're suitable.
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.