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 Diet Chart for Male — Prescription Options in the UK
A weight loss diet chart for men is most effective when combined with appropriate support — and that may include prescription medication. In the UK, if you have a BMI of 30 or above, or 27 or above with weight-related health conditions, you may be eligible for prescription weight loss treatment. This guide covers the three UK-licensed medications available, NHS eligibility criteria, and how to find out whether you qualify. Use our free BMI calculator above to check your starting point, and our GLP-1 weight loss calculator to see projected outcomes with medication support.
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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-only medications are licensed in the UK for weight management in men:
- Mounjaro (tirzepatide) — A once-weekly injection that activates two natural hormone pathways (GIP and GLP-1). In clinical trials, men taking Mounjaro lost an average of 15–21% of body weight alongside dietary changes and increased physical activity. Doses range from 2.5 mg to 15 mg weekly.
- Wegovy (semaglutide) — A once-weekly GLP-1 injection. Clinical trials showed an average weight loss of approximately 15% body weight at the maximum 2.4 mg dose. The dose range is 0.25 mg to 2.4 mg weekly.
- Saxenda (liraglutide) — A daily GLP-1 injection with a maximum dose of 3 mg. Average weight loss is approximately 5–10% body weight.
All three are prescription-only and require a clinical assessment before being prescribed. 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 — How to Get Started
In the UK, you can access prescription weight loss medication through two routes. NHS access is via specialist tier 3 weight management services — your GP can refer you, but availability and waiting times vary significantly by region. Private access is available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber, without needing an NHS referral.
To find out if you're eligible, calculate your BMI using our free BMI calculator on this page. If your BMI is 30 or above, or 27 or above with conditions like type 2 diabetes, high blood pressure, or sleep apnoea, you may qualify. Start by speaking with your GP about your weight loss goals — they can discuss your options and either refer you to NHS services or advise you on private options.
- 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's the difference between Mounjaro and Wegovy for men?
Both are once-weekly injections. Mounjaro is a dual GIP/GLP-1 agonist (activating two hormone pathways) while Wegovy is a GLP-1 agonist only. Clinical trials show Mounjaro may deliver slightly higher average weight loss (~15–21% vs ~15%), but individual results vary significantly. Both require prescription and clinical assessment.
Can I get GLP-1 weight loss medication on the NHS?
Yes, but access is through specialist weight management services (tier 3), not standard GP prescription. Your GP can refer you, but waiting times vary by region — some areas have significant delays. Private access through online prescribing services is faster and available without NHS referral.
What BMI do I need to be eligible for prescription weight loss medication?
Generally, a BMI of 30 or above. However, if you have weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea, cardiovascular disease), you may qualify at a BMI of 27 or above. Use our free BMI calculator above to check your status.
Do I need a diet chart to use prescription weight loss medication?
Yes — prescription medications like Mounjaro and Wegovy work alongside dietary changes and increased physical activity. They're not replacements for lifestyle changes. Your GP or prescriber can advise on appropriate calorie targets. The NHS recommends losing 0.5–1 kg per week as a sustainable rate.
How much weight can I expect to lose with medication?
Clinical trial averages are 15–21% of body weight with Mounjaro and ~15% with Wegovy — but individual results vary significantly. Actual outcomes depend on your starting weight, diet adherence, physical activity level, and how your body responds. Use our GLP-1 weight loss calculator to see projected outcomes based on your dose.
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.