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
What Are the Benefits of Wegovy?
Wegovy (semaglutide) is a prescription-only, once-weekly GLP-1 receptor agonist injection licensed in the UK for weight management in adults. Clinical trials have shown that Wegovy may help people lose weight and improve certain health markers when used alongside a reduced-calorie diet and increased physical activity. However, individual results vary significantly, and Wegovy is not suitable for everyone. Understanding the research evidence behind Wegovy benefits can help you make an informed decision about whether this prescription medication might be right for you.
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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.
Weight Loss and Health Improvements from Wegovy
The STEP-1 clinical trial, which examined semaglutide at the weight management dose (Wegovy), showed that participants using the 2.4 mg dose lost an average of approximately 14.9% of their body weight over 68 weeks, compared to 2.4% in the placebo group. This means someone weighing 100 kg might lose around 15 kg on average — though results vary considerably between individuals.
- Improvements in blood sugar control (helpful if you have prediabetes or type 2 diabetes)
- Reduced blood pressure in some users
- Lower triglyceride levels (a type of fat in the blood)
- Improved cardiovascular health markers
- Better weight distribution and reduced waist circumference
These benefits extend beyond weight loss itself. Even a 5–10% reduction in body weight can improve joint pain, reduce sleep apnoea symptoms, and lower the risk of weight-related health conditions. Wegovy works by activating the GLP-1 receptor pathway, which helps regulate appetite, reduce food cravings, and support feeling fuller after smaller meals.
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 Wegovy Fits Into Weight Management
Wegovy is typically prescribed as part of a comprehensive weight management plan rather than as a standalone solution. It is most effective when combined with dietary changes and increased physical activity. In the UK, you can access Wegovy through NHS specialist weight management services (tier 3) or via a private prescription following an online clinical assessment with a licensed prescriber.
To understand how Wegovy might benefit you personally, it's helpful to check your current BMI and see where you stand on NHS health thresholds. Use our free BMI calculator above to assess your starting point. Our GLP-1 weight loss calculator can then help you project potential weight loss outcomes at different Wegovy doses — giving you realistic expectations before speaking with a prescriber.
- 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 is the main benefit of Wegovy compared to other weight loss methods?
Wegovy is a prescription medication that works by targeting natural appetite-regulation pathways in your body. Unlike diet alone, Wegovy may help reduce hunger and cravings, making it easier to maintain a calorie deficit. Clinical trials show average weight loss of around 15%, though this varies between individuals.
Can Wegovy help if I have type 2 diabetes or prediabetes?
Yes. Wegovy may help improve blood sugar control in people with type 2 diabetes or prediabetes. However, if you're already taking diabetes medications, your prescriber may need to adjust your doses. Always inform your prescriber of all existing medications before starting Wegovy.
How does Wegovy compare to Mounjaro for weight loss?
Both are GLP-1-based injections licensed in the UK for weight management. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1-only agonist. Some clinical data suggests Mounjaro may produce slightly higher average weight loss, but individual results vary significantly. A prescriber can advise which is more appropriate for you.
Will I keep the weight off after stopping Wegovy?
Weight regain is common when stopping Wegovy if lifestyle changes are not maintained. Wegovy is typically used as part of long-term weight management, not as a short-term fix. Your prescriber will discuss whether continued use is appropriate for your individual health goals.
Is Wegovy available on the NHS in the UK?
Wegovy is approved by NICE and available through NHS specialist weight management services (tier 3). However, availability and waiting times vary significantly by region. Many people access Wegovy privately through GPhC-registered online pharmacies following a clinical assessment, which can be faster than NHS routes.
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.