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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Best Weight Loss Supplements For Men in the UK
If you're looking for weight loss supplements for men in the UK, the most effective evidence-based options are actually prescription weight loss medications rather than over-the-counter supplements. Three GLP-1 and GIP receptor agonist medications are currently licensed in the UK for weight management: Mounjaro, Wegovy, and Saxenda. These work by regulating appetite and food cravings, and clinical trials have shown significant results when combined with lifestyle changes. Whether you're eligible depends on your BMI and health circumstances. This guide explains how they work, who can access them, and whether through the NHS or private prescription.
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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 Weight Loss Medications Explained
Three prescription weight loss medications are currently licensed in the UK for adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea.
Mounjaro (tirzepatide) is a once-weekly injection that activates both GIP and GLP-1 hormone pathways. Clinical trials showed participants lost an average of 15–21% of their body weight over 72 weeks — though individual results vary. Starting dose is 2.5 mg, escalating to a maximum of 15 mg.
Wegovy (semaglutide) is also a once-weekly injection, working through the GLP-1 pathway alone. Average weight loss in trials was approximately 15% of body weight. It starts at 0.25 mg and reaches a maximum of 2.4 mg.
Saxenda (liraglutide) is a daily injection with similar GLP-1 mechanism to Wegovy. All three require a prescription, clinical assessment, and are used alongside reduced-calorie diet and increased physical activity. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses.
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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 and Getting Started
In the UK, prescription weight loss medication is available through two routes. NHS access is through specialist tier 3 weight management services — you'll typically need a GP referral, though availability and waiting times vary significantly by region. Private access is through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber, and medication can be prescribed without 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 27–29.9 with a weight-related health condition, start a conversation with your GP about weight management support. They can discuss whether prescription medication is appropriate for you and explain your options for both NHS and private access. Weight management is a medical decision that should always involve professional assessment.
- 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.
Are weight loss supplements or prescription medications better for men?
Prescription medications like Mounjaro and Wegovy have strong clinical trial evidence showing 15–clinically studied weight loss on average. Most over-the-counter supplements lack this evidence. Prescription options require clinical assessment but are more likely to be effective when combined with lifestyle changes.
How much weight can men lose with Mounjaro or Wegovy?
Clinical trials showed average weight loss of 15–21% of body weight with Mounjaro and approximately 15% with Wegovy over several months. Individual results vary significantly and depend on starting weight, dose, diet, and activity level. Results are not assured.
How do I know if I'm eligible for prescription weight loss medication on the NHS?
You're typically eligible if your BMI is 30 or above, or 27–29.9 with a weight-related health condition like diabetes or high blood pressure. Use our free BMI calculator to check your BMI, then discuss eligibility with your GP. Availability varies by region.
Can I get weight loss injections privately if the NHS waiting list is too long?
Yes. Private GPhC-registered pharmacies offer prescription weight loss medication following an online clinical assessment. You don't need an NHS referral. Costs vary by dose and provider but typically range from £129–£320 monthly depending on the medication.
Do weight loss medications work without diet and exercise changes?
Prescription weight loss medications are designed to work alongside reduced-calorie diet and increased physical activity — not instead of them. Clinical trial results were achieved when participants combined medication with lifestyle changes. Results without these changes are likely to be much more modest.
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.