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 Boot Camp Thailand and UK Prescription Options
Weight loss boot camps in Thailand can offer intensive support, but many UK adults are unaware that prescription weight management options are available closer to home. If you're considering a boot camp abroad, it's worth exploring NHS-aligned alternatives first. This guide covers UK-licensed medications for weight management, eligibility criteria, and how to discuss options with your GP. Our GLP-1 weight loss calculator can help you understand potential outcomes with prescription medication, and our BMI calculator shows where you stand relative to NHS thresholds.
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
Three prescription-only weight loss medications are currently licensed in the UK for adults with obesity or overweight with health conditions:
- Mounjaro (tirzepatide) — dual GIP and GLP-1 receptor agonist, once-weekly injection. Clinical trials showed average weight loss of 15–21% of body weight over 72 weeks when combined with diet and exercise.
- Wegovy (semaglutide) — GLP-1 receptor agonist, once-weekly injection. Average weight loss of approximately 15% of body weight in clinical trials alongside lifestyle changes.
- Saxenda (liraglutide) — GLP-1 receptor agonist, once-daily injection. Earlier medication with proven efficacy for weight management.
Each medication requires a prescription from a UK-licensed prescriber and a clinical assessment to confirm eligibility. Individual results vary significantly — these figures are clinical trial averages, not assured outcomes. All three work alongside reduced-calorie diet and increased physical activity, not instead of them.
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 vs Private Access and How to Start
In the UK, prescription weight loss medications are available through two routes:
- NHS route: Referral to a tier 3 specialist weight management service via your GP. Availability varies by region and waiting times can be lengthy.
- Private route: Online consultation with a UK-licensed prescriber. Available without NHS referral if you meet eligibility criteria — typically BMI 30+ or BMI 27–29.9 with weight-related conditions like diabetes, high blood pressure, or sleep apnoea.
Start by speaking with your GP about your weight management goals. They can assess your health, calculate your BMI, and discuss whether prescription medication is appropriate for you. Use our free BMI calculator above to understand your current status relative to NHS thresholds before your appointment.
- 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.
Am I eligible for prescription weight loss medication in the UK?
Generally, you may be eligible if you have a BMI of 30 or above, or a BMI of 27–29.9 with a weight-related health condition such as type 2 diabetes, high blood pressure, or sleep apnoea. Adults of South Asian, Chinese, Black African, or Black Caribbean heritage may qualify at lower BMI thresholds. A prescriber will assess your individual circumstances.
How much weight can I realistically lose with Mounjaro or Wegovy?
Clinical trials showed average weight loss of 15–21% of body weight with Mounjaro and approximately 15% with Wegovy over several months. However, individual results vary significantly depending on dose, adherence, diet, and exercise. These medications work best alongside a reduced-calorie diet and increased physical activity.
What's the difference between a weight loss boot camp and prescription medication?
Boot camps offer intensive physical activity and dietary coaching in a group setting, often abroad. Prescription medications work by reducing appetite and supporting feeling fuller, and are taken at home alongside your own diet and exercise plan. Many people combine both approaches, though medication provides a structured, medically-supervised option.
How do I access prescription weight loss treatment through the NHS?
Ask your GP for a referral to your local tier 3 specialist weight management service. Your GP will assess your health and BMI first. NHS availability varies significantly by region, and waiting lists can be several months. Private prescribing options are available without NHS referral if you meet eligibility criteria.
Are weight loss injections like Mounjaro and Wegovy assured to work?
No medication assures weight loss. Mounjaro and Wegovy help reduce appetite and support feeling fuller, but require commitment to diet and exercise changes. Results depend on individual factors including genetics, metabolism, adherence to medication, and lifestyle changes. Your prescriber will monitor your progress and adjust treatment as needed.
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.