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
Weight Loss Balloon — Understanding UK Options
A weight loss balloon is a gastric balloon procedure where an inflatable device is temporarily placed in the stomach to help reduce appetite and food intake. In the UK, there are several weight management approaches available for adults struggling with excess weight, ranging from prescription medications to surgical interventions. Understanding your options and eligibility is the first step toward sustainable weight management. Use our free BMI calculator above to check where you currently stand, then explore the prescription weight loss alternatives that may be suitable for you.
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 Prescription Weight Loss Options
If you're exploring weight management in the UK, prescription medications are a clinically proven alternative to consider. The most widely available prescription weight loss options are GLP-1 receptor agonist injections, which have strong evidence from clinical trials.
- Mounjaro (tirzepatide) — A dual GIP and GLP-1 agonist approved by the MHRA for weight management. Clinical trials showed participants lost an average of 15–21% of their body weight over 72 weeks, though individual results vary. Maximum dose is 15 mg once weekly.
- Wegovy (semaglutide) — A GLP-1 agonist licensed for weight management in UK adults. STEP trial data showed average weight loss of approximately 15% of body weight at the maximum dose of 2.4 mg once weekly.
- Saxenda (liraglutide) — Also MHRA-approved, administered as a daily injection. Available through NHS specialist services and private prescribing.
All three are prescription-only medicines requiring clinical assessment before dispensing. They work by regulating appetite hormones and may support feeling fuller after smaller meals, making them a practical option for eligible adults seeking nhs weight loss support or private access.
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.
Eligibility and How to Access Weight Management Support
Eligibility for prescription weight loss medication in the UK depends on your BMI and health status. Adults with a BMI of 30 kg/m² or above, or 25–29.9 kg/m² with weight-related health conditions (type 2 diabetes, hypertension, cardiovascular disease, sleep apnoea), may qualify.
Try our GLP-1 weight loss calculator to see projected outcomes at different medication doses. Access is available through two routes: NHS weight management services (via referral from your GP to a specialist tier 3 service — availability varies by region) or private online prescribing (following an online clinical assessment with a UK-licensed prescriber). Your GP is your starting point — discuss your weight management goals and ask about referral options or private alternatives. They can also confirm your BMI category using our free weight converter tool.
- 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 a weight loss balloon available through the NHS in the UK?
Gastric balloons are available through some NHS trusts but access is extremely limited and typically only for patients with severe obesity awaiting bariatric surgery. Prescription weight loss medications like Mounjaro and Wegovy are increasingly available through NHS specialist services, and access is more readily available than balloon procedures across most UK regions.
What is the difference between a weight loss balloon and GLP-1 medication?
A gastric balloon is a temporary surgical procedure (usually 6 months) that physically reduces stomach capacity. GLP-1 medications like Wegovy and Mounjaro work by signalling satiety to the brain and regulating appetite hormones. Both aim to reduce food intake, but GLP-1s are non-invasive, require no procedure, and can be used long-term.
Am I eligible for prescription weight loss medication if I'm interested in weight management?
Eligibility depends on your BMI and health profile. Adults with BMI ≥30, or BMI 27–29.9 with weight-related conditions like diabetes or hypertension, may qualify. Use our free BMI calculator to check your current BMI, then discuss prescription options with your GP or a private prescriber.
Can I access Mounjaro or Wegovy on the NHS?
Yes, both Mounjaro and Wegovy are available through NHS specialist weight management (tier 3) services following referral from your GP. However, waiting times and availability vary significantly by region. Private access is often faster — available through online prescribers following clinical assessment.
How much weight loss can I expect with prescription weight loss injections?
Clinical trials showed average weight loss of 15–21% of body weight with Mounjaro and around 15% with Wegovy over 12–18 months, though individual results vary significantly. Weight loss depends on dose, adherence, diet, and exercise. Our weight loss calculator can provide a personalised projection based on your circumstances.
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.