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
2 Pound Weight Loss: UK Prescription Options
Losing 2 pounds (approximately 0.9 kg) per week is possible with the right approach, though the NHS recommends a sustainable rate of 0.5 to 1 kg weekly for most adults. For eligible individuals, prescription weight loss medication can support your weight management goals alongside diet and exercise. This guide explains UK-licensed options, eligibility criteria, and how to access prescription support through the NHS or privately. Calculate your personal BMI and weight loss potential using our free tools to help you understand what's right for you.
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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 Prescription Weight Loss Medications
Three prescription-only medications are currently licensed in the UK for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). All three work as GLP-1 (or dual GIP/GLP-1) receptor agonists, helping regulate appetite and support feeling fuller after eating.
Mounjaro and Wegovy are once-weekly injections with stronger evidence for weight loss. In clinical trials, Mounjaro users lost an average of 15–21% of body weight, whilst Wegovy showed approximately 15% average loss—though individual results vary significantly. Saxenda is a daily injection that may help achieve modest weight loss over time.
All three require a prescription following a clinical assessment by a UK-licensed healthcare professional. They are typically prescribed alongside reduced-calorie diet and increased physical activity for best results. Try our free GLP-1 weight loss calculator to explore potential outcomes at different medication doses.
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 and Eligibility
In the UK, prescription weight loss medication is available through two routes: NHS specialist weight management services or private prescribing clinics. NHS access requires referral from your GP to a tier 3 specialist service, though waiting lists can be substantial in many regions. Private access is faster—assessment and prescription through an online licensed prescriber, then dispensed by a GPhC-registered pharmacy.
To be eligible, you typically need a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or heart disease. If you're from a South Asian, Chinese, Black African, or Black Caribbean background, lower BMI thresholds may apply due to higher health risk at lower weights. Speak to your GP to discuss which option and medication suits your circumstances best.
- 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.
Is losing 2 pounds per week safe?
The NHS recommends losing 0.5–1 kg (1–2 lbs) per week as a safe, sustainable rate. Losing 2 pounds weekly is within this range. However, achieving this requires a significant calorie deficit and is most safely managed with professional support, especially if using prescription medication or medical intervention.
What is the difference between Mounjaro and Wegovy?
Mounjaro is a dual GIP and GLP-1 receptor agonist with average weight loss of 15–21%, whilst Wegovy activates GLP-1 only, showing approximately 15% average loss. Both are once-weekly injections. Mounjaro and Wegovy have comparable effectiveness, but individual response varies. Your prescriber will recommend based on your health profile.
How do I know if I'm eligible for prescription weight loss medication?
You may be eligible if your BMI is 30 or above, or 27–29.9 with weight-related health conditions like diabetes or high blood pressure. Use our free BMI calculator to check your BMI, then discuss eligibility with your GP. Lower thresholds apply for certain ethnic backgrounds.
Can I get prescription weight loss medication through the NHS?
Yes, through NHS specialist (tier 3) weight management services. Your GP can refer you, though waiting times vary by region. Alternatively, private online prescribing services offer faster access if you meet eligibility criteria and can fund the treatment privately, typically costing £130–£320 monthly depending on dose.
What should I do if I want to lose 2 pounds per week?
Start by calculating your BMI using our free tool and logging a baseline weight in our progress tracker. Speak to your GP about safe, sustainable targets for your situation. If eligible, discuss prescription weight loss medication as a support option. Combine any medication with a reduced-calorie diet and increased physical activity for best results.
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.