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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50 Pound Weight Loss: UK Prescription Medication Options
Losing 50 pounds (approximately 23 kg) is a significant health goal that many UK adults pursue through lifestyle changes, and for some, with prescription weight management support. The NHS and private prescribers offer several evidence-based medication options for eligible adults. Understanding these options, who qualifies, and how to access them is the first step towards sustainable weight loss. This guide covers UK-licensed weight loss medications, eligibility criteria, and how to explore whether prescription treatment might support your weight management journey.
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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 Weight Loss Medications Explained
Three prescription-only weight loss medications are currently licensed in the UK: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). Mounjaro and Wegovy are once-weekly injections, while Saxenda is a daily injection. All work by activating natural hormone pathways that regulate appetite and help you feel fuller after eating.
Clinical trials show these medications can support meaningful weight loss. In SURMOUNT-1 trials, Mounjaro helped participants lose an average of 15–21% of their body weight over 72 weeks, whilst Wegovy (in STEP-1 trials) supported approximately 15% average weight loss. For a person weighing 127 kg (20 stone), a 15–clinically studied weight loss would be around 19–25 kg (3–4 stone or 42–55 pounds). Individual results vary and depend on dose, adherence, diet, and physical activity.
- Both medications are prescription-only and require clinical assessment
- Available through NHS specialist weight management services or private prescribers
- Most effective when combined with reduced-calorie diet and increased activity
- Work differently to diabetes medications — GLP-1 and GIP receptors regulate appetite, not blood sugar directly
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.
Eligibility and How to Access Weight Loss Medication in the UK
You may be eligible for prescription weight loss medication if you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, prediabetes, high blood pressure, or sleep apnoea. If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply — your prescriber can advise.
NHS access: Referral to your local tier 3 specialist weight management service through your GP. Services vary by region and waiting lists can be lengthy. Private access: Online consultation with a UK-licensed prescriber, typically within days. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses, and our BMI calculator to check where you currently stand on NHS weight classifications.
- Contact your GP to discuss eligibility and referral options
- Private prescribers assess via online consultation in minutes
- Costs vary — typically £129–£320/month privately depending on dose
You may be eligible for prescription weight loss medication if you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply.
NHS access: Referral through your GP to your local tier 3 specialist weight management service. Availability and waiting times vary significantly by region. Private access: Online consultation with a UK-licensed prescriber, typically assessed within days. Check your current BMI using our free BMI calculator, and explore potential weight loss outcomes with our GLP-1 weight loss calculator to understand what a 50-pound loss might look like at different medication doses.
- Start by discussing options with your GP
- Private prescribers assess eligibility via online video or phone consultation
- Costs typically range from £129–£320/month depending on medication and dose
- 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 I lose 50 pounds with weight loss medication?
Clinical trials show that eligible adults can lose 15–21% of body weight with prescription medications like Mounjaro or Wegovy when combined with diet and exercise. For someone weighing 127 kg, this could mean 42–55 pounds lost over several months. Individual results vary significantly — some lose more, some less. Your prescriber will set realistic expectations based on your starting weight and health.
How much weight can I lose in 3 months with prescription medication?
Most people on prescription weight loss medication lose 0.5–2 kg per week, depending on the medication, dose, and adherence. In 12 weeks, this could be 6–24 kg (13–53 pounds). However, weight loss is typically slower in the first 4 weeks and varies month to month. Your GP or prescriber can give you a personalised projection.
What's the difference between Mounjaro and Wegovy?
Both are once-weekly injections for weight loss. Mounjaro (tirzepatide) activates two hormone pathways (GIP and GLP-1), whilst Wegovy (semaglutide) activates one (GLP-1). Clinical data suggests Mounjaro may produce slightly higher average weight loss (20.9% vs 14.9%), but both are effective. Choice depends on your health profile and prescriber recommendation.
Can I get weight loss medication on the NHS?
Yes, through NICE-approved tier 3 specialist weight management services. Your GP must refer you if you meet eligibility criteria (BMI ≥30, or ≥27.5 with comorbidities). NHS availability varies by region — some areas have short waits, others have long lists. Ask your GP about your local service and waiting times.
What happens if I stop taking weight loss medication?
Weight typically begins to return if you stop medication without maintaining diet and lifestyle changes. Most people regain weight gradually over weeks to months. Prescription weight loss medication is most effective as part of long-term weight management, not a short-term fix. Your prescriber will discuss ongoing use and sustainability with you.
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.