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
Cheapest Weight Loss Surgery Options in the UK
Weight loss surgery can be expensive in the UK, but options exist at different price points through both NHS and private providers. However, before considering surgery, it's worth understanding the full range of weight management strategies available, including prescription weight loss medication, which may be more affordable and less invasive. This guide explores surgical and non-surgical options to help you make an informed decision about your weight loss journey.
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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.
Weight Loss Surgery Costs in the UK
Gastric bypass surgery typically costs £8,000–£15,000 privately in the UK, whilst gastric band surgery ranges from £5,000–£10,000. Gastric sleeve surgery costs approximately £7,000–£12,000. These prices vary significantly by provider, location, and complexity of the procedure.
- NHS weight loss surgery is available but requires referral through specialist tier 4 services and typically involves waiting lists of 6–24 months depending on your region
- Private providers often offer faster access but at significantly higher cost
- All bariatric surgery carries surgical risks including infection, blood clots, and nutritional deficiencies requiring lifelong monitoring
- Recovery typically takes 4–6 weeks, with full results appearing over 12–18 months
For those seeking more affordable weight management options, prescription weight loss injections and structured diet programmes through the NHS may be available sooner and at lower overall cost.
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.
Non-Surgical Weight Loss Alternatives
Prescription weight loss medication offers a more affordable entry point for weight management in the UK. GLP-1 weight loss injections like Wegovy (semaglutide) and Mounjaro (tirzepatide) typically cost £129–£320 per month privately, significantly less than surgery. NHS access to weight loss medication varies by region but is increasingly available through specialist weight management services.
These prescription medications work by reducing appetite and supporting feeling fuller after smaller meals. Clinical trials showed Wegovy helps users lose an average of around 15% body weight, whilst Mounjaro achieves approximately 15–clinically studied weight loss on average—though individual results vary considerably. Both require a clinical assessment and are prescribed alongside lifestyle changes including diet and exercise, not instead of them.
- 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's the cheapest weight loss surgery available on the NHS?
NHS bariatric surgery is free but access depends on your BMI, health conditions, and regional availability. Most regions have 6–24 month waiting lists. Gastric bands are typically the least invasive, though gastric bypass and sleeve gastrectomy are more commonly performed. Your GP can refer you to a tier 4 specialist service for assessment.
How much does weight loss surgery cost privately in the UK?
Gastric band surgery costs £5,000–£10,000, gastric sleeve £7,000–£12,000, and gastric bypass £8,000–£15,000 privately. Costs vary by surgeon, hospital, and location. Many private providers offer payment plans. Always check what's included—some prices exclude pre-surgery tests or follow-up appointments.
Are weight loss injections cheaper than surgery?
Yes. Prescription weight loss injections like Wegovy and Mounjaro cost £129–£320 per month privately, totalling roughly £1,500–£3,800 per year—significantly less than one-time surgical costs. NHS access to weight loss medication is expanding, making it even more affordable. Use our GLP-1 weight loss calculator to estimate potential results.
Can I get weight loss surgery free on the NHS?
Yes, NHS bariatric surgery is free if you meet eligibility criteria (typically BMI ≥35, or BMI ≥30 with weight-related health conditions) and have tried structured weight management first. However, waiting lists are long in many regions. Your GP can assess your eligibility and refer you to specialist services.
What's a realistic alternative to weight loss surgery?
Prescription weight loss medication alongside structured diet and exercise is an evidence-based, more affordable alternative. NHS weight management services also offer behaviour change programmes. Check our BMI calculator to understand your current status, then speak to your GP about referral to NHS weight management services or assessment for prescription medication.
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.