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
Cambogia Weight Loss — What Works in the UK
Garcinia cambogia supplements are often promoted for weight loss, but scientific evidence supporting their effectiveness is limited. If you're looking for evidence-based weight management support in the UK, prescription medications like Mounjaro, Wegovy, and Saxenda offer clinically proven alternatives for eligible adults. This guide explains what's available on the NHS and privately, and how to find out if you qualify for prescription weight loss treatment.
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 Management Options
If you're interested in weight management medication in the UK, several prescription-only options are licensed and available:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist, once-weekly injection. Clinical trials showed participants lost an average of 15–21% of their body weight alongside diet and exercise.
- Wegovy (semaglutide) — a GLP-1 receptor agonist, once-weekly injection. Evidence suggests average weight loss of around 15% body weight in clinical trials.
- Saxenda (liraglutide) — a GLP-1 receptor agonist, once-daily injection. Provides sustained weight management support for eligible adults.
All three are prescription-only medicines requiring a clinical assessment. Your doctor or prescriber will evaluate your eligibility based on your BMI, health conditions, and individual circumstances. Use our free BMI calculator above to check where you stand, and our GLP-1 weight loss calculator to explore potential outcomes 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 vs Private Access — How to Get Started
NHS route: Referral to a specialist tier 3 weight management service through your GP. Availability and waiting times vary significantly by region. Your GP can advise whether you're eligible and how to access local services.
Private route: Online consultation with a UK-licensed prescriber. If clinically appropriate, a prescription is issued and dispensed by a registered pharmacy. No NHS referral needed, though costs vary by dose and provider.
Next step: Speak to your GP about prescription weight loss treatment. They can discuss whether medication is appropriate for you, assess your health profile, and explain what's available through the NHS or recommend private options. Prescription weight management works best alongside diet and physical activity changes.
- 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 garcinia cambogia effective for weight loss?
Scientific evidence for garcinia cambogia (hydroxycitric acid) is mixed and limited. Most studies show modest effects, if any, on weight loss. Prescription medications like Mounjaro and Wegovy have much stronger clinical evidence supporting their effectiveness for weight management in the UK.
What are the eligibility requirements for prescription weight loss medication in the UK?
Adults with a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions (such as type 2 diabetes, high blood pressure, or sleep apnoea), may be eligible. Check your BMI using our free calculator above, then discuss your options with your GP or a licensed prescriber.
How much weight can I expect to lose with prescription medication?
Results vary significantly between individuals. Clinical trials show average weight loss of 15–21% body weight with Mounjaro and around 15% with Wegovy, alongside reduced-calorie diet and increased physical activity. Our GLP-1 weight loss calculator can help you estimate potential outcomes based on current dose information.
Can I get prescription weight loss medication on the NHS?
Yes, Mounjaro and other licensed medications are available through NHS specialist weight management services. Referral and access vary by region, and waiting times can be lengthy. Your GP can refer you or advise what's available in your area.
How do I know if prescription weight loss treatment is right for me?
Speak to your GP or a licensed healthcare professional. They'll assess your health, discuss your weight loss goals, review any underlying conditions, and explain whether medication is appropriate alongside lifestyle changes. Individual medical advice always requires a professional assessment.
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.