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 Medication for Heart Failure in the UK
If you have heart failure and are overweight, weight management can be an important part of your health plan. In the UK, adults with heart failure and excess weight may be eligible for prescription weight loss medication alongside lifestyle changes and medical management. This guide explains the UK-licensed options available, how to access them through the NHS or privately, and what you need to know before speaking to your GP about weight management support.
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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 Prescription Weight Loss Options
Three prescription medications are currently licensed in the UK for weight management and may be considered for eligible adults with heart failure and overweight or obesity:
- Mounjaro (tirzepatide) — a once-weekly injection that works as a dual GIP and GLP-1 receptor agonist. Clinical trials showed average weight loss of 15–21% of body weight over 72 weeks when combined with a reduced-calorie diet and physical activity.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Clinical trials demonstrated average weight loss of approximately 15% of body weight at the maximum dose.
- Saxenda (liraglutide) — a daily GLP-1 injection for weight management.
All are prescription-only medicines requiring clinical assessment. Your prescriber will evaluate whether medication is suitable for your individual health situation, including your heart condition.
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.
Accessing Weight Loss Medication: NHS vs Private
NHS access: Weight loss medication is available through NHS tier 3 specialist weight management services. Your GP can refer you, though availability varies significantly by region and waiting lists can be lengthy. The NHS focuses on eligibility based on BMI and weight-related health conditions.
Private access: GPhC-registered online pharmacies offer prescription weight loss medication following an online clinical assessment with a UK-licensed prescriber. This route doesn't require NHS referral. Costs vary by dose and provider, typically ranging from £129–£320 monthly.
Next step: Start by discussing weight management with your GP, who understands your heart condition and current medications. They can advise on NHS eligibility and referral options.
- 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 heart failure?
Weight loss medication may be considered for some people with heart failure and excess weight, but it depends on your specific condition and medications. Your GP or cardiologist must assess whether it's safe for you. Some blood pressure medications and heart treatments can interact with GLP-1 drugs, so professional medical evaluation is essential before starting any prescription weight loss treatment.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are once-weekly injections licensed for weight management in the UK. Mounjaro (tirzepatide) activates two hormone pathways (GIP and GLP-1), while Wegovy (semaglutide) activates one (GLP-1 only). Clinical trials suggest Mounjaro may produce slightly higher average weight loss, but individual results vary significantly. Your prescriber will recommend the most suitable option for your health profile.
How much weight will I lose with prescription weight loss medication?
Clinical trials showed average weight loss of 15–21% of body weight with these medications, but results vary widely between individuals. Some people lose more, others less. Weight loss medication works alongside a reduced-calorie diet and increased physical activity — it's not a standalone treatment. Your own results depend on your starting weight, adherence to lifestyle changes, and individual metabolism.
How do I find out if I'm eligible for NHS weight loss medication?
Speak to your GP first. You may be eligible if your BMI is 30 or above, or 27 or above with weight-related health conditions (which may include heart disease). NHS eligibility also depends on your region and local commissioning. Your GP can assess you, discuss options, and refer you to specialist weight management services if appropriate. Waiting times vary by area.
Can I use our BMI calculator and weight loss projection tools to plan my weight management?
Yes. Use the free BMI calculator on this page to check your current BMI and understand where you fall on NHS guidance. Try our GLP-1 weight loss calculator to see potential weight loss projections at different doses if you're considering medication. Track your progress with our free progress tracker once you've started your weight management plan. These tools are informational and complement, not replace, medical advice from your GP.
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.