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
Ozempic for Weight Loss in the UK — What You Need to Know
Ozempic (semaglutide) is not licensed for weight loss in the UK, though it's widely discussed online for this purpose. Ozempic is approved only for type 2 diabetes management at doses up to 2mg. For weight management, the UK-licensed option is Wegovy, which contains the same active ingredient at a higher dose (up to 2.4mg). This guide explains the difference, UK-licensed prescription weight loss alternatives, and how to find out if you're eligible. Use our free GLP-1 weight loss calculator to explore potential outcomes with licensed weight management medications.
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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-Licensed Weight Loss Medication Options
Ozempic is not licensed for weight loss in the UK—using it off-label for weight management is not recommended. However, three prescription weight management options are licensed and available to eligible UK adults:
- Wegovy (semaglutide 2.4mg) — GLP-1 receptor agonist, once-weekly injection. Average weight loss: approximately 15% body weight in clinical trials.
- Mounjaro (tirzepatide) — Dual GIP/GLP-1 agonist, once-weekly injection. Average weight loss: approximately 15–21% body weight in clinical trials.
- Saxenda (liraglutide) — GLP-1 receptor agonist, once-daily injection. Older option, still available.
All are prescription-only and require clinical assessment. Individual results vary significantly. These medications work alongside reduced-calorie diet and increased physical activity, not instead of them. Your prescriber will assess your suitability based on your health, BMI, and any weight-related conditions.
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 & How to Access Weight Loss Medication
To access prescription weight loss medication on the NHS, you typically need a BMI of 30 or above (or 27+ with weight-related health conditions like type 2 diabetes, high blood pressure, or sleep apnoea). Refer to your GP, who may refer you to a specialist tier 3 weight management service. NHS access varies significantly by region and waiting lists can be lengthy. Privately, weight loss medications are available through online GPhC-registered pharmacies following a clinical assessment—no NHS referral needed. Use our free BMI calculator to check your current BMI and understand your starting point. Whichever route you choose, speak with your GP first—they know your full health picture and can guide you toward the most appropriate option for safe, sustainable weight management.
- 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 Ozempic licensed for weight loss in the UK?
No. Ozempic (semaglutide up to 2mg) is approved only for type 2 diabetes in the UK. Wegovy (semaglutide 2.4mg) is the licensed weight management version. Using Ozempic for weight loss would be off-label and is not recommended.
What's the maximum dose of Wegovy in the UK?
The maximum dose of Wegovy is 2.4mg once weekly. Dosing starts at 0.25mg and increases gradually over 16+ weeks. Your prescriber determines the right dose for you based on tolerance and response.
What's the maximum dose of Mounjaro for weight loss?
The maximum dose of Mounjaro for weight loss is 15mg once weekly. Dosing starts at 2.5mg and increases weekly after the first four weeks. Not everyone reaches the maximum dose—prescribers adjust based on individual response and side effects.
What's the difference between Ozempic and Wegovy?
Both contain semaglutide but serve different purposes. Ozempic (up to 2mg) is for type 2 diabetes only. Wegovy (up to 2.4mg) is specifically licensed for weight management. Never use Ozempic as a weight loss medication—use the licensed Wegovy instead.
How do I find out if I'm eligible for weight loss medication on the NHS?
Your GP can assess your eligibility based on your BMI and weight-related health conditions. Most services require BMI ≥30, or ≥27 with conditions like diabetes or high blood pressure. Waiting times vary by region—ask your GP about local specialist weight management services.
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.