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
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How to Get a Wegovy Prescription in the UK
Wegovy (semaglutide) is a prescription-only weight management injection licensed in the UK for adults with obesity or overweight with health complications. A Wegovy prescription is only available following a clinical assessment with a healthcare professional. You can access it through NHS specialist weight management services or private online prescribing. This guide explains eligibility, how to get prescribed Wegovy, the difference between NHS and private routes, and what happens after your prescription is issued.
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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.
Wegovy Prescription Routes in the UK
In the UK, you can access a Wegovy prescription through two main routes:
- NHS specialist services: Your GP refers you to a tier 3 or 4 weight management service. NICE has approved semaglutide for NHS use, but availability and waiting times vary significantly by region. Some areas have waiting lists of several months. You must meet NICE eligibility criteria.
- Private prescribing: Available through online consultations with UK-licensed prescribers. Following a clinical assessment (usually a questionnaire and video call), you can receive a prescription dispensed by a GPhC-registered pharmacy. This route is faster but involves private costs.
Unlike Ozempic (which is approved for type 2 diabetes), Wegovy is specifically the licensed weight management version of semaglutide in the UK. Try our GLP-1 weight loss calculator to understand potential outcomes at different doses.
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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.
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Wegovy Eligibility and the Prescription Process
You may be eligible for a Wegovy prescription if you have a BMI of 30 kg/m² or above, or BMI of 27–29.9 with a weight-related health condition (type 2 diabetes, high blood pressure, heart disease, sleep apnoea, or high cholesterol). For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply.
Before prescribing, a healthcare professional will assess your medical history, current medications, and whether Wegovy is appropriate for you. You cannot take Wegovy if you are pregnant, breastfeeding, have thyroid cancer history, or are allergic to semaglutide. Check your BMI using our BMI calculator to see if you may meet the criteria for consideration.
The prescription process includes checking for contraindications, reviewing your weight loss goals and lifestyle changes, and discussing side effects. Once prescribed, Wegovy is delivered by post. The starting dose is 0.25 mg once weekly, escalating by 0.25 mg every 4 weeks up to a maximum of 2.4 mg. Prescription costs vary — typically £129–£320 per month depending on dose and provider. NHS prescriptions are free, but availability depends on your regional integrated care board (ICB) and specialist service capacity.
- 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 difference between Wegovy and Ozempic?
Both contain semaglutide, but Ozempic is licensed for type 2 diabetes (doses up to 2 mg) and Wegovy is licensed for weight management (up to 2.4 mg). Ozempic is not licensed for weight loss in the UK. Wegovy is the approved weight management version and can only be prescribed for that purpose.
How long does it take to get a Wegovy prescription on the NHS?
This varies significantly by region. Some NHS specialist weight management services have waiting lists of 3–12 months. Private prescribing is usually faster (assessments completed within days), but involves cost. Contact your local ICB or GP to find out waiting times in your area.
Can my GP prescribe Wegovy directly?
Your GP cannot prescribe Wegovy directly. NHS prescriptions are issued by specialist tier 3 or 4 weight management services after referral from your GP. Your GP can refer you to these services, but they must assess you first.
What happens if I don't meet NICE eligibility criteria?
If you don't meet NHS NICE criteria, private prescribing may still be available following a clinical assessment with a private UK-licensed prescriber. Eligibility is assessed individually. You could also ask your GP about other weight management support options.
Is Wegovy safe and does it really work?
Wegovy is approved by the MHRA and has been studied extensively. Clinical trials (STEP programme) showed participants lost an average of approximately 15% of body weight using semaglutide alongside diet and exercise — though individual results vary. Common side effects include nausea and diarrhoea. Always discuss risks and benefits with your prescriber.
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.