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
Are Bananas Ok For Weight Loss?
Yes, bananas can be part of a weight loss plan when eaten in moderation. A medium banana contains around 105 calories and provides fibre, potassium, and natural carbohydrates that support energy levels during weight management. However, portion control matters โ eating multiple bananas daily adds significant calories. If you're pursuing weight loss through diet, exercise, or prescription medication, understanding how individual foods fit into your overall calorie intake is key. For many eligible adults in the UK, prescription weight loss medications are also available alongside dietary changes.
10,000+ calculations today ยท NHS-aligned thresholds ยท 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/mยฒ).
While BMI isn't a perfect measure โ it doesn't account for muscle mass, bone density, or fat distribution โ 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 โ 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
If you're aiming for sustainable weight loss alongside dietary changes like moderating banana intake, prescription weight loss medications may be available to you in the UK. Mounjaro (tirzepatide) and Wegovy (semaglutide) are the most commonly prescribed GLP-1 weight loss injections, alongside Saxenda (liraglutide). These work by helping regulate appetite and reduce food cravings, making it easier to maintain a calorie deficit.
To be eligible for prescription weight loss medication in the UK, you typically need 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. In clinical trials, these medications helped participants lose an average of 15โ21% of their body weight โ though individual results vary significantly. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses, and calculate your BMI using our calculator to assess your eligibility range.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care โ 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 โ 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 โ completely free.
NHS vs Private Access โ How to Find Out What's Right for You
In the UK, prescription weight loss medication is available through two main routes. NHS access is through specialist tier 3 weight management services โ your GP can refer you, though waiting lists vary by region and availability is not uniform across all areas. Private access is available through GPhC-registered online prescribers who assess your eligibility following an online consultation, without requiring an NHS referral.
Whether you're focusing on balanced nutrition (including appropriately-portioned bananas) or exploring medication options, your GP is the best starting point. They can discuss your weight loss goals, assess any underlying health conditions, and advise whether prescription medication is suitable for you. Both dietary approaches and medication work best when combined with increased physical activity and sustainable lifestyle changes.
- 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 โ 5mg โ 7.5mg โ 10mg โ 12.5mg โ 15mg
- GLP-1 receptor agonist
- Up to 15โ17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg โ 0.5mg โ 1mg โ 1.7mg โ 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 | 15โ22.5% | 12โ17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20โ32 weeks | 16โ20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | ยฃ150โยฃ250/month | ยฃ150โยฃ300/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 โ 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 eat bananas on a weight loss diet?
Yes, bananas can fit into a weight loss plan. A medium banana has around 105 calories and provides fibre and potassium. The key is portion control and accounting for them within your daily calorie intake. Eating one banana as part of a balanced diet is generally fine; eating multiple bananas daily may add excessive calories.
What's the difference between Mounjaro and Wegovy for UK weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist; Wegovy (semaglutide) activates GLP-1 alone. Both are once-weekly injections licensed for weight management in UK adults. Clinical trials showed Mounjaro achieved average weight loss of 15โ21%, Wegovy around 15%. Individual results vary significantly, and prescriber assessment determines which is appropriate for you.
How do I know if I'm eligible for prescription weight loss medication in the UK?
You're typically eligible if you have a BMI of 30 or above, or 27 or above with weight-related conditions like type 2 diabetes or high blood pressure. Use our free BMI calculator to check your BMI, then discuss eligibility with your GP or a licensed online prescriber following a clinical assessment.
Is prescription weight loss medication available through the NHS?
Yes, prescription weight loss medication is available through NHS specialist tier 3 weight management services. Your GP can refer you, though waiting lists and availability vary significantly by region. Private access through online prescribers is also available without an NHS referral.
Should I use weight loss medication instead of changing my diet?
No. Weight loss medications work best alongside dietary changes and increased physical activity, not instead of them. Even with medication, sustainable weight loss requires balanced nutrition โ including foods like bananas in appropriate portions โ combined with lifestyle changes and medical support.
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.