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
Men Weight Loss Medication in the UK
Weight loss can be challenging, especially for men managing busy lifestyles. If you're overweight or obese and struggling to lose weight through diet and exercise alone, prescription weight management medication may be an option worth discussing with your GP. The UK now has several licensed weight loss medications available, and many men are eligible for support through the NHS or private prescribing. Our GLP-1 weight loss calculator can help you estimate potential results, whilst our free BMI calculator shows where your current weight sits on the NHS scale.
10,000+ calculations today · NHS-aligned thresholds · 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/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
Three main medications are licensed for weight management in the UK:
- Mounjaro (tirzepatide) — A once-weekly injection that activates both GIP and GLP-1 hormone pathways. Clinical trials showed men lost an average of 15–21% of body weight alongside reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — A once-weekly GLP-1 injection. Average weight loss was approximately 15% of body weight in clinical trials.
- Saxenda (liraglutide) — A daily GLP-1 injection, available for several years in the UK.
All three are prescription-only medicines and require a clinical assessment before being prescribed. A prescriber will evaluate your BMI, medical history, and weight-related health conditions to determine eligibility. Our weight converter tool can help you understand your weight in different UK measurements whilst you consider your options.
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, weight loss medication can be accessed through two main routes:
- NHS: Through specialist tier 3 or tier 4 weight management services following a GP referral. NICE has approved tirzepatide (Mounjaro) for NHS use, though availability and waiting times vary significantly by region. Some ICBs have substantial waiting lists.
- Private: Through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. Private access is faster and does not require an NHS referral, though there are associated costs.
Whether you're eligible depends on your BMI and whether you have weight-related health conditions such as type 2 diabetes, high blood pressure, or heart disease. Start by speaking with your GP about your weight management goals.
- 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 BMI qualifies me for weight loss medication in the UK?
Adults with a BMI of 30 or above, or a BMI of 27–29.9 with at least one weight-related health condition (such as type 2 diabetes or high blood pressure) may be eligible. Use our free BMI calculator to check your personal BMI instantly. For men of South Asian, Black African, or Black Caribbean heritage, slightly lower BMI thresholds may apply.
How much weight can I expect to lose with Mounjaro or Wegovy?
Clinical trials showed average weight loss of 15–21% with Mounjaro and approximately 15% with Wegovy over several months. However, individual results vary significantly and depend on your starting weight, adherence, diet, and exercise. These medications work best alongside lifestyle changes, not instead of them.
Can I access weight loss injections through the NHS?
Yes, Mounjaro is now approved for NHS specialist weight management services. However, access requires a GP referral to tier 3 or tier 4 services, and availability varies by region. Some areas have long waiting lists. Your GP can advise whether you're eligible and what the waiting time is in your area.
What are the main side effects of Mounjaro and Wegovy?
Very common side effects include nausea, diarrhoea, constipation, and stomach pain. These often improve over time. Less common side effects include injection site reactions, fatigue, and headaches. Serious side effects are rare but can include severe stomach pain (possible pancreatitis) or gallbladder issues. Your prescriber will discuss risks before starting treatment.
Is weight loss medication right for me?
A prescriber can assess whether weight loss medication is suitable based on your individual health, BMI, medical history, and lifestyle. Start by discussing your weight management goals with your GP, who can refer you to NHS specialist services or advise on private options. Many men find medication helpful alongside diet and exercise changes for achieving sustainable weight loss.
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.