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
Who Makes Wegovy and How Does It Work?
Wegovy is manufactured by Novo Nordisk, a Danish pharmaceutical company specialising in weight management and diabetes care. The active ingredient is semaglutide, a GLP-1 receptor agonist that helps regulate appetite and support sustainable weight loss. Wegovy is prescription-only in the UK and licensed for weight management in adults. It's different from Ozempic, which also contains semaglutide but is approved only for type 2 diabetes — not for weight loss. Understanding who makes your medication and how it works helps you make informed health decisions.
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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.
Novo Nordisk and Semaglutide Development
Novo Nordisk is a global pharmaceutical leader founded in 1923 and headquartered in Copenhagen, Denmark. The company specialises in diabetes, obesity, and haemophilia treatments. Novo Nordisk developed semaglutide as a GLP-1 receptor agonist — a medication that mimics the natural hormone GLP-1 produced in your gut after eating.
Semaglutide was originally developed for type 2 diabetes management (marketed as Ozempic). Clinical trials then showed semaglutide's potential for weight management at higher doses. This led to the development of Wegovy — a once-weekly injectable form specifically licensed for weight loss in adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions.
In clinical trials (STEP-1), Wegovy helped participants lose an average of approximately 15% of their body weight — though individual results vary. The GLP-1 weight loss calculator on this page can help you estimate 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.
How to Access Wegovy in the UK
In the UK, Wegovy is prescription-only. Access is available through two routes:
- NHS route: Referral to a specialist tier 3 weight management service via your GP. NHS availability varies significantly by region and waiting lists can be lengthy.
- Private route: Online consultation with a UK-licensed prescriber, followed by prescription dispensing through a GPhC-registered pharmacy. This is typically faster and available without NHS referral.
A prescriber will assess your eligibility based on your BMI, health history, and any weight-related conditions. Wegovy is available in doses from 0.25 mg to 2.4 mg, taken once weekly. Use our free BMI calculator above to check whether you may meet the eligibility criteria for prescription weight loss treatment.
- 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.
What's the difference between Wegovy and Ozempic?
Both contain semaglutide and are made by Novo Nordisk, but Ozempic is licensed only for type 2 diabetes (doses up to 2 mg) whereas Wegovy is licensed specifically for weight management (doses up to 2.4 mg). Using Ozempic for weight loss is off-label and not recommended in the UK — Wegovy is the licensed option.
How does semaglutide help with weight loss?
Semaglutide is a GLP-1 receptor agonist that activates natural gut hormone pathways. It may help reduce appetite, increase feelings of fullness, and slow how quickly food leaves your stomach. These effects work alongside reduced-calorie diet and increased physical activity to support sustainable weight loss.
Is Wegovy available on the NHS in the UK?
Yes, Wegovy can be prescribed through NHS specialist tier 3 weight management services, but access varies significantly by region and waiting times can be very long. Private access through licensed online prescribers is typically faster but involves a cost — usually £129–£280 per month depending on dose.
What's the recommended Wegovy dose for weight loss?
Wegovy starts at 0.25 mg weekly, escalating every 4 weeks to 0.5 mg, 1 mg, 1.7 mg, and finally 2.4 mg. Most people reach the 2.4 mg maintenance dose by week 17. Your prescriber will determine the appropriate dose based on your response and tolerance.
How much weight can you expect to lose on Wegovy?
Clinical trials showed an average weight loss of approximately 15% of body weight over 68 weeks at the 2.4 mg dose — but individual results vary significantly. Weight loss depends on your starting weight, diet, activity level, and personal response. Track your progress using our free progress tracker to monitor your personal results.
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.