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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7-Day Protein Diet Plan For Weight Loss: UK Options
A 7-day protein-focused diet plan can help support weight loss through increased satiety and muscle preservation. However, sustainable weight management in the UK often combines dietary changes with other approaches—including prescription medications for eligible adults. This guide covers protein diet basics and explores NHS-approved prescription weight loss options like Mounjaro and Wegovy. Remember, individual results vary, and any significant dietary or medical changes should be discussed with your GP.
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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 Prescription Weight Loss Medications: What's Available
For eligible UK adults, prescription weight management medications can support weight loss alongside dietary changes like protein-focused eating plans. Three main options are licensed in the UK:
- Mounjaro (tirzepatide)—a dual GIP and GLP-1 receptor agonist, given as a once-weekly injection. Clinical trials showed average weight loss of 15–21% of body weight over 72 weeks when combined with a reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide)—a GLP-1 receptor agonist, also injected once weekly. Evidence suggests average weight loss of around 15% of body weight in clinical trials.
- Saxenda (liraglutide)—a GLP-1 receptor agonist given as a daily injection, with similar mechanisms to Wegovy.
All three are prescription-only and require clinical assessment. Eligibility typically includes 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. Try our free GLP-1 weight loss calculator to explore projected outcomes at different doses.
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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.
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NHS vs Private Access: How to Get Started
NHS access: Mounjaro and Wegovy are available through specialist tier 3 weight management services. You'll need a GP referral, though availability varies significantly by region and waiting lists can be lengthy in many areas.
Private access: Both medications are available through UK-licensed online prescribers and GPhC-registered pharmacies. This route doesn't require NHS referral and can be faster, though you'll pay privately.
To find out if you're eligible, calculate your BMI using our free tool above. If your BMI suggests you may qualify, have a conversation with your GP about prescription weight loss options. They can assess your individual health and discuss whether medication is appropriate for you, alongside dietary approaches like increased protein intake and nhs weight loss support.
- 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.
How much weight can a 7-day protein diet plan help me lose?
Weight loss depends on calorie intake, activity level, and individual metabolism. A 7-day plan alone is unlikely to produce significant lasting results—sustainable weight loss typically requires 4–12 weeks of consistent dietary changes. The NHS recommends losing 0.5–1 kg per week. A high-protein approach may reduce appetite and support muscle preservation during calorie deficit, but results vary. Consult your GP for personalised advice.
Can prescription weight loss medication replace a protein diet plan?
No. Medications like Mounjaro and Wegovy work best alongside dietary changes and increased physical activity—not instead of them. A balanced approach combining nutrition, exercise, and medication (if eligible) tends to produce the best results. Your prescriber will emphasise that medication supports, rather than replaces, lifestyle changes.
Who is eligible for prescription weight loss medication in the UK?
UK adults with 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), may be eligible. Use our free BMI calculator to check your BMI. Eligibility is assessed individually by a prescriber—your GP can provide guidance on whether you meet NHS or private prescription criteria.
What's the difference between NHS and private prescription weight loss in the UK?
NHS access is through specialist weight management services (tier 3) following a GP referral. Availability varies by region and waiting lists can be long. Private access is available through online UK-licensed prescribers and pharmacies—faster but you pay directly. Both offer the same prescription medications; the difference is route and cost.
Is a 7-day protein diet safe for everyone?
High-protein diets are generally safe for most adults, but not for everyone. Those with kidney disease, certain liver conditions, or specific medical histories should seek GP advice first. Pregnant or breastfeeding women should consult their healthcare provider. A GP can advise whether a high-protein approach suits your individual health profile.
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.