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
9Lb Weight Loss: UK Prescription Medication Options
Losing 9 pounds is a realistic short-term goal that many UK adults work towards as part of longer-term weight management. If you're interested in prescription support for weight loss, several licensed medications are available in the UK. This guide explains your options, who is eligible, and how to access treatment through the NHS or privately. We'll help you understand how medications like Mounjaro and Wegovy work, and whether they might be suitable for you. Use our free BMI calculator to check where you currently stand, and our GLP-1 weight loss calculator to explore potential outcomes with medication support.
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 Weight Loss Medications
Three prescription-only medications are licensed in the UK for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). All are GLP-1 receptor agonists (or in Mounjaro's case, a dual GIP/GLP-1 agonist) that work by reducing appetite and helping you feel fuller after smaller meals.
Clinical evidence: In trials, Mounjaro helped adults lose an average of 15–21% of their body weight, whilst Wegovy achieved around 15% loss on average. Individual results vary significantly and depend on diet, exercise, and dose.
- Both are once-weekly injections (except Saxenda, which is daily)
- All are prescription-only and require a clinical assessment
- Eligibility is based on BMI and weight-related health conditions
- They work best alongside a reduced-calorie diet and increased physical activity
To understand if your weight falls into a range where medication might be considered, check your BMI using our free BMI calculator above.
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: the NHS or privately.
NHS access: Referral to a specialist tier 3 weight management service through your GP. Availability varies by region and waiting times can be substantial. Ask your GP about services in your area.
Private access: Online consultation with a UK-licensed prescriber followed by dispensing through a registered pharmacy. Faster access but involves costs (typically £129–£320 per month depending on dose).
Next step: Book an appointment with your GP to discuss weight loss goals. They can assess your BMI, review any weight-related health conditions, and advise on NHS eligibility or referral pathways. Track your progress with our free progress tracker as you work towards your 9lb goal and beyond.
- 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 does 9lb weight loss actually mean in UK measurements?
9 pounds equals approximately 4.1kg or 0.64 stone. Using our free weight converter, you can track progress in whichever unit feels most natural. For context, losing 9lb represents roughly a 5% body weight reduction for many adults, which has proven health benefits including improved blood sugar control and reduced joint strain.
Will prescription weight loss medication assures I lose 9lb?
No. Weight loss medications may help, but individual results vary significantly based on diet, exercise, genetics, and dose. Clinical trials show average losses, not individual assures. Medication works best alongside a reduced-calorie diet and increased physical activity. Your prescriber will discuss realistic expectations during assessment.
Am I eligible for prescription weight loss medication in the UK?
You may be eligible if your BMI is 30 or above, or 27–29.9 with a weight-related health condition (diabetes, high blood pressure, heart disease, sleep apnoea, or high cholesterol). Lower thresholds apply if you're of South Asian, Chinese, Black African, or Black Caribbean heritage. Use our BMI calculator to check your status, then speak to your GP.
Can I get weight loss medication on the NHS?
Yes, but access is through specialist tier 3 weight management services, not routine GP prescription. You'll need a GP referral. Availability and waiting times vary significantly by region. Contact your GP practice to ask about services in your area and typical waiting lists.
How quickly can I access prescription weight loss medication privately?
Private access is typically faster—often within days. You'll have an online consultation with a UK-licensed prescriber, and if approved, the prescription is dispensed by a registered pharmacy. This route involves costs (usually £129–£320 monthly depending on dose), unlike NHS access which is free once prescribed through specialist services.
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.