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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Losing 10lb: UK Prescription Weight Loss Options
Losing 10lb (approximately 4.5kg) is a realistic and achievable goal, especially when combined with lifestyle changes and professional support. If you're looking to lose weight in the UK, prescription medication may be an option depending on your BMI and health circumstances. This guide covers the licensed weight management medications available on the NHS and privately, who is eligible, and how to explore what might work for you. Check your starting BMI using our free BMI calculator above to understand your health context better.
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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
The UK has three prescription medications licensed for weight management in adults: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These are GLP-1 receptor agonists (or dual GIP/GLP-1 in Mounjaro's case) that work by helping regulate appetite and supporting feelings of fullness. In clinical trials, these medications helped participants lose an average of 15–21% of their body weight over several months—far exceeding 10lb for most users. Mounjaro and Wegovy are injected once weekly, while Saxenda is a daily injection. All three are prescription-only and require a clinical assessment before use. Eligibility typically requires a BMI of 30 or above, or 27 or above with at least one weight-related health condition such as type 2 diabetes, high blood pressure, or sleep apnoea. For people of South Asian, Black African, Caribbean, or Chinese heritage, lower BMI thresholds may apply. Individual results vary, and these medications work best alongside a reduced-calorie diet and increased physical activity.
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.
Getting Weight Loss Medication in the UK: NHS vs Private
NHS access: Weight loss medication is available through specialist tier 3 weight management services, which you can be referred to by your GP. However, NHS waiting lists vary significantly by region—some areas have lengthy queues of several months to years. Private access: GPhC-registered online services offer prescription weight loss medication following a clinical assessment with a UK-licensed prescriber. This is typically faster than NHS routes but involves a cost (usually £129–£320 per month depending on dose). To find out if you're eligible, speak with your GP about your weight management goals and medical history. Your GP can discuss whether prescription medication is appropriate for you, or refer you to specialist services if suitable. Use our free BMI calculator to check your starting point, and our GLP-1 weight loss calculator to explore potential outcomes at different doses.
- 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.
Will 10lb of weight loss be noticeable?
Yes, losing 10lb (4.5kg) is typically noticeable in how clothes fit and how you feel. The NHS recommends losing 0.5–1kg per week as sustainable, so 10lb is achievable in 4–9 weeks with medication, diet, and exercise combined. Most people report improved energy and better joint health at this level of loss.
Am I eligible for prescription weight loss medication?
You may be eligible if your BMI is 30 or above, or 27 or above with a weight-related health condition (diabetes, high blood pressure, sleep apnoea, etc.). The best way to find out is to speak with your GP, who can assess your individual circumstances and either prescribe medication or refer you to specialist services.
How quickly will I lose 10lb on Mounjaro or Wegovy?
This varies individually, but clinical trials show most people lose 0.5–1kg per week when medication is combined with a reduced-calorie diet and physical activity. 10lb (4.5kg) would typically take 4–9 weeks to lose. Our GLP-1 weight loss calculator can help you estimate a timeline based on your starting weight and dose.
Can I get weight loss medication on the NHS?
Yes, but availability varies by region. Your GP can refer you to a tier 3 specialist weight management service, though waiting lists can be lengthy. Private options are available sooner through GPhC-registered online prescribing services, with costs typically ranging from £129–£320 per month.
What's the difference between Mounjaro, Wegovy, and Saxenda?
Mounjaro is a dual GIP/GLP-1 agonist with once-weekly dosing; Wegovy is a GLP-1 agonist, also once-weekly; Saxenda is a GLP-1 agonist given daily. Mounjaro showed slightly higher average weight loss in trials (~21%) compared to Wegovy (~15%), though individual results vary significantly. Your prescriber will advise which is most suitable for 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.