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 Non-Diabetic Adults
Ozempic is a prescription medication containing semaglutide, but it's important to understand that using Ozempic for weight loss in non-diabetic adults is considered off-label in the UK. If you're looking for prescription weight management options in the UK, there are dedicated, licensed alternatives specifically approved for this purpose. This guide explains what's available through the NHS, how private prescription weight loss medication works, and who may be eligible for treatment.
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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 Management Medications
Rather than Ozempic, the UK has dedicated prescription weight loss injections specifically licensed for weight management. Wegovy (semaglutide 2.4 mg) and Mounjaro (tirzepatide) are both approved for weight management and are the preferred choices for GLP-1 weight loss. Saxenda (liraglutide) is also licensed but is a daily injection rather than weekly.
In clinical trials, Wegovy helped participants lose an average of around 15% of their body weight, whilst Mounjaro showed average weight loss of 15–21% — though individual results vary significantly. Both are available through NHS specialist weight management services or via private online prescribing following a clinical assessment. Use our GLP-1 weight loss calculator to estimate potential results at different doses, and check your BMI with our free BMI calculator to understand your starting point.
These licensed medications are preferred over off-label use because they've undergone rigorous testing specifically for weight management in non-diabetic adults, and dosing is tailored for this purpose.
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 For Weight Loss Medication
NHS access: Through specialist tier 3 weight management services. You'll need a GP referral, and eligibility typically requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, hypertension, or cardiovascular disease. Waiting times vary by region; some areas have lengthy lists.
Private access: Via online consultation with a UK-licensed prescriber. No NHS referral needed. Available to adults meeting similar clinical criteria. Costs typically range from £129–£320 per month depending on dose. Your prescriber will assess your medical history and suitability before issuing a prescription, which is then dispensed by a GPhC-registered pharmacy. Either route involves genuine prescription weight loss medication UK systems—never unlicensed alternatives.
- 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.
Can I use Ozempic off-label for weight loss if I'm not diabetic?
Technically possible but not recommended. Ozempic is licensed for type 2 diabetes, not weight management. UK doctors can prescribe off-label, but it's not the standard approach. Licensed alternatives like Wegovy and Mounjaro are specifically approved for non-diabetic weight loss and are preferred. Always discuss options with your GP or a licensed prescriber.
What's the difference between Ozempic and Wegovy?
Both contain semaglutide but at different doses and purposes. Ozempic is approved for diabetes (up to 2 mg), whilst Wegovy is licensed for weight management (up to 2.4 mg). Wegovy is the correct choice for weight loss in non-diabetic adults and is specifically tested for this use. Using Ozempic for weight loss is off-label, whereas Wegovy is purpose-designed.
How do I know if I'm eligible for prescription weight loss medication in the UK?
Generally, you need a BMI of 30 or above, or 25–29.9 with a weight-related health condition. South Asian, Chinese, Black African, or Black Caribbean adults may have lower thresholds. Your GP can assess eligibility, or you can have an online clinical assessment through a private prescriber. Use our BMI calculator to check your starting point.
How much weight loss should I expect with licensed GLP-1 medication?
Clinical trials show average weight loss of 15–21% of body weight over several months, alongside diet and exercise. Individual results vary considerably—some lose more, others less. Weight loss typically continues for 6–12 months, then plateaus. Our GLP-1 weight loss calculator can help estimate potential outcomes based on dose.
What happens if I stop taking weight loss medication?
Weight loss may slow or reverse over time if lifestyle changes aren't maintained. These medications work best when combined with sustained calorie deficit and physical activity. Your prescriber can discuss long-term management plans, which may include ongoing treatment or transition to lifestyle maintenance. Progress tracking helps identify what's working for you.
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.