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
Post Weight Loss Tummy Tuck and Weight Management in the UK
A tummy tuck (abdominoplasty) is sometimes considered after significant weight loss, but prescription weight management options are now available in the UK that may help prevent the need for surgery altogether. If you're thinking about this journey, understanding your weight management options — including medication available through the NHS and privately — can help you make informed decisions about your health before considering surgical intervention.
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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 Prescription Weight Management Options
Several prescription medications are now licensed in the UK for weight management and may help eligible adults lose weight sustainably. These are typically prescribed as part of comprehensive weight loss programmes alongside diet and physical activity changes.
- Mounjaro (tirzepatide) — a once-weekly injection that works as a dual GLP-1 and GIP receptor agonist, helping regulate appetite and support feeling fuller after meals. In clinical trials, participants lost an average of 15–21% of their body weight.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Clinical trials showed average weight loss of approximately 15% of body weight when combined with lifestyle changes.
- Saxenda (liraglutide) — a daily GLP-1 injection for those who prefer daily dosing rather than weekly injections.
All three are prescription-only medicines requiring assessment by a healthcare professional. Try our free GLP-1 weight loss calculator to explore how these medications might support your weight loss goals at different 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 Eligibility and How to Access Weight Management Support
To access prescription weight loss medication on the NHS, 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 cardiovascular disease. Start by speaking with your GP, who can refer you to your local tier 3 specialist weight management service. However, NHS waiting lists vary significantly by region.
Alternatively, prescription weight management is available privately through licensed prescribers following an online clinical assessment. Check your eligibility instantly using our free BMI calculator — knowing your current BMI helps you understand what options may be available to you.
- 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.
Do I need a tummy tuck after weight loss?
Not necessarily. A tummy tuck is a surgical choice, not a requirement. Many people lose significant weight without surgery. Prescription weight management medications, combined with exercise and strength training, can help improve skin elasticity and muscle tone over time. Discuss your individual situation with your GP.
What is the difference between Mounjaro and Wegovy for weight loss?
Both are prescription injections given once weekly, but they work slightly differently. Mounjaro is a dual GIP and GLP-1 agonist, while Wegovy is a GLP-1 agonist alone. Clinical trials show both support meaningful weight loss. Your prescriber will assess which is more suitable based on your health profile.
How long does it take to see results with weight loss medication?
Results vary between individuals. Some people see changes within 4–8 weeks, while others take longer. Weight loss medications work best alongside dietary changes and increased physical activity. Sustainable weight loss typically occurs at 0.5–1 kg per week, which is the NHS-recommended safe rate.
Can I get weight loss medication on the NHS?
Yes, if you meet eligibility criteria (BMI ≥30 or ≥27.5 with comorbidities). Speak with your GP about referral to a specialist weight management service. NHS availability and waiting times vary by region. Private options are also available through licensed prescribers.
What should I do before considering a tummy tuck?
Explore all weight management options first. Work with your GP or a specialist to achieve your target weight through sustainable methods, including medication if appropriate. Strength training can improve skin tone. Only consider surgery once weight is stable, typically after weight loss has plateaued for 3–6 months.
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.