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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Weight Loss and COPD: Safe Options in the UK
Managing weight with COPD (chronic obstructive pulmonary disease) requires careful consideration, as excess weight can strain the respiratory system. The good news is that safe weight loss and weight management UK options are available for eligible adults, including prescription medications and NHS support. This guide explains how prescription weight loss medication works, who qualifies under NHS guidelines, and how to discuss options with your GP.
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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.
Prescription Weight Loss Options Available in the UK
Three GLP-1 receptor agonist medications are licensed in the UK for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These medications work by regulating appetite, helping you feel fuller after smaller meals, and supporting sustainable weight loss alongside diet and exercise changes.
Eligibility for prescription weight loss medication in the UK typically requires: a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions (which may include COPD-related complications like heart disease or type 2 diabetes). For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply.
In clinical trials, weight loss injections showed promising results: Mounjaro helped participants lose an average of 15–21% of body weight, while Wegovy showed approximately 14.9% average loss. However, individual results vary, and these medications are most effective alongside reduced-calorie diet and increased physical activity. Check your BMI using our free BMI calculator to see where you currently stand and whether you may be eligible for prescription support.
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 Support vs Private Access: How to Get Started
In the UK, weight loss medication access is available through two routes. The NHS route involves referral to a tier 3 specialist weight management service from your GP. Availability varies significantly by region, and waiting lists can be lengthy in many areas. Your GP can assess whether referral is appropriate and discuss local services.
The private route allows you to access prescription weight loss treatment through UK-licensed online prescribers following a clinical assessment, without NHS referral. Costs typically range from £129–£320 per month depending on the medication and dose.
Start by speaking with your GP about your weight management goals and any COPD-related concerns. They can advise on NHS eligibility, discuss your individual health needs, and explore options suited to your respiratory condition. Use our free progress tracker to log your weight and health improvements as you begin your weight loss journey.
- 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 take weight loss injections if I have COPD?
Possibly, but only with careful medical assessment. Your prescriber will review your COPD severity, medications, and overall health before prescribing. GLP-1 medications can cause nausea and changes in appetite, which may affect COPD management. Always inform your GP or prescriber that you have COPD, and discuss any respiratory concerns before starting treatment.
Will losing weight help my COPD symptoms?
Yes, evidence suggests that even modest weight loss (5–10% of body weight) can improve breathing and reduce strain on the respiratory system. Excess weight increases the work required to breathe, so losing weight may ease symptoms, improve exercise tolerance, and support better COPD control alongside your current treatment.
How quickly can I expect to see weight loss results?
Weight loss varies individually and depends on the medication, dose, diet, and activity level. Most people begin seeing results within 4–8 weeks, with steady progress over months. The NHS recommends losing no more than 0.5–1 kg per week for sustainable, safe weight loss. Consistent effort with diet and exercise maximises results.
What happens if weight loss medication isn't suitable for me?
If prescription medication isn't appropriate due to COPD or other factors, your GP can discuss alternative weight management strategies. These include structured dietary support, supervised exercise programmes, behaviour change coaching, and tier 2 NHS weight management services. Many approaches can support healthy weight loss without medication.
How do I know if I'm eligible for NHS weight loss treatment?
Your GP can assess your eligibility based on your BMI, health conditions (including COPD-related complications), and individual circumstances. Generally, a BMI of 30 or above, or 27–29.9 with health complications, may qualify. Book a GP appointment to discuss your weight and COPD management together.
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.