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
Weight Loss Breakfasts and Medication in the UK
Starting your day with a nutritious breakfast is important for weight management, but breakfast alone won't achieve weight loss. In the UK, prescription weight loss medication is available for eligible adults alongside dietary changes. This guide explains how breakfast fits into an overall weight management strategy, the UK-licensed medication options available, and how to find out if you're eligible. Whether you're exploring dietary improvements or prescription support, understanding all your options helps create a sustainable plan. Use our free BMI calculator to establish your current health baseline and assess your eligibility.
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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-Licensed Prescription Weight Loss Options
For adults in the UK seeking weight management support, three prescription-only medicines are currently licensed: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These GLP-1 medications work by regulating appetite and food cravings, supporting your body's natural hunger signals. Clinical trials show that alongside a reduced-calorie diet and increased physical activity, these medications may help adults lose an average of 15–21% of their body weight over time—though individual results vary significantly.
- Mounjaro: Once-weekly injection, dual GIP and GLP-1 agonist, doses range from 2.5 mg to 15 mg
- Wegovy: Once-weekly injection, GLP-1 agonist, maximum dose 2.4 mg
- Saxenda: Once-daily injection, GLP-1 agonist, maximum dose 3 mg
You're potentially eligible if your BMI is 30 or above, or 27 or above with a weight-related health condition such as type 2 diabetes, high blood pressure, or sleep apnoea. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, NHS guidance recommends lower BMI thresholds. A prescriber will assess your individual circumstances through a clinical consultation. Try our GLP-1 weight loss calculator to explore projected outcomes at different medication doses.
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 in the UK
NHS access to weight loss medication is through specialist tier 3 and 4 weight management services, typically accessed via GP referral. Availability and waiting times vary significantly by region and local Integrated Care Board (ICB). Some areas have long waiting lists; others offer faster access. Private access is available through GPhC-registered online prescribing services, which assess your eligibility through an online clinical consultation and issue a prescription if appropriate. Private costs vary but typically range from £129–£320 per month depending on dose and provider.
The key first step is a conversation with your GP, who can: assess your BMI and health context, refer you to NHS specialist services if appropriate, or advise you about private options. Your GP can also rule out any medical reasons why medication might not be suitable. Whether you choose NHS or private routes, prescription weight loss medication is most effective when combined with sustainable breakfast choices, a reduced-calorie diet, and increased physical activity.
- 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 breakfast alone help me lose weight without medication?
A nutritious, protein-rich breakfast supports weight loss by reducing cravings later in the day. However, sustainable weight loss requires a calorie deficit—typically losing 0.5–1 kg per week is safest. For some people, breakfast alone isn't sufficient. Prescription weight loss medication, used alongside dietary changes and exercise, may help if your BMI qualifies you for NHS or private treatment.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) activates two hormone pathways (GIP and GLP-1), while Wegovy (semaglutide) activates one (GLP-1 only). Clinical trials suggest Mounjaro may achieve slightly higher average weight loss—around 20.9% at maximum dose compared to Wegovy's 14.9%—though results vary. Both are once-weekly injections prescribed following clinical assessment.
How do I know if I'm eligible for prescription weight loss medication in the UK?
You may be eligible if your BMI is 30 or above, or 27 or above with a weight-related health condition such as type 2 diabetes or high blood pressure. For people of South Asian or Black African heritage, lower BMI thresholds apply. Use our free BMI calculator to check your current BMI, then discuss eligibility with your GP or a private prescriber.
Will prescription weight loss medication work better than changing my breakfast habits?
Medication and breakfast improvements work best together, not as alternatives. A healthy, protein-rich breakfast supports weight loss, helps control hunger, and prevents overeating. Prescription medication enhances this by regulating appetite hormones. The combination of dietary changes, physical activity, and medication (if eligible) provides the most sustainable results.
How do I start the process to get weight loss medication in the UK?
Book an appointment with your GP to discuss your weight, health, and BMI. Your GP can refer you to NHS specialist weight management services or provide information about private prescribing options. A clinical assessment determines eligibility based on your BMI, health conditions, and current medications. Private online prescribers offer faster assessment if you prefer to explore that route.
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.