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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What Is Wegovy and How to Access It in the UK
Wegovy is a prescription-only weight management injection containing semaglutide, a GLP-1 receptor agonist licensed in the UK for adults with obesity or overweight with health conditions. It's a once-weekly injection that works by reducing appetite and helping you feel fuller after smaller meals. Access in the UK is possible through both NHS specialist services and private online prescribing, though costs, waiting times, and eligibility vary significantly depending on your route. This guide covers what Wegovy is, how much it costs, and how to access it.
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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 Cost and Private Access in the UK
Private Wegovy costs in the UK typically range from £129 to £320 per month depending on your dose and provider. Wegovy comes in five escalating doses: 0.25mg, 0.5mg, 1mg, 1.7mg, and 2.4mg (the maximum maintenance dose). You'll usually start at 0.25mg and increase gradually every 4 weeks if tolerated. Each pre-filled pen contains four weekly injections, so a month's supply is one pen per dose level. Private prescription routes involve an online consultation with a UK-licensed prescriber who assesses your eligibility, medical history, and suitability. If approved, a prescription is issued and dispensed by a GPhC-registered pharmacy. The entire process typically takes 1–2 working days. Unlike NHS routes, private access doesn't require a GP referral or specialist service waiting list, making it accessible for those who don't qualify for NHS funding or prefer faster access.
- Monthly private cost: approximately £129–£320 (varies by provider and dose)
- Each pen = 4 weeks' supply (4 injections)
- Online consultation with UK prescriber required
- No NHS referral or waiting list needed
- Dispensed by GPhC-registered pharmacy
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 Access vs Private: Routes and Eligibility
NHS route: You must be referred by your GP to a tier 3 specialist weight management service. NICE has approved tirzepatide (Mounjaro) and semaglutide for NHS use, but availability and waiting times vary dramatically by region — some areas have waiting lists exceeding 12 months. There is no cost to you if prescribed through the NHS. Private route: Complete an online health assessment with a prescriber, receive a prescription if eligible, and collect from a pharmacy within days — no GP referral needed. Private prescriptions cost £129–£320 monthly depending on dose. Eligibility for both routes: BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, sleep apnoea, cardiovascular disease). South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds. Our GLP-1 weight loss calculator can help you explore potential outcomes at different doses.
- 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 exactly is Wegovy and how does it work?
Wegovy is semaglutide, a GLP-1 receptor agonist injection licensed for weight management in UK adults. It reduces appetite, slows stomach emptying, and helps you feel fuller after smaller meals. You inject once weekly under your skin — typically in the stomach, thigh, or upper arm. Clinical trials showed average weight loss of around 15% of body weight at the maximum dose alongside diet and exercise.
How much does Wegovy cost on the NHS?
Wegovy is free if prescribed through the NHS. However, access is limited and managed through specialist tier 3 weight management services. You must be referred by your GP, and availability varies significantly by region. Some areas have substantial waiting lists. Ask your GP whether your local service offers semaglutide or tirzepatide.
What's the difference between Wegovy and Mounjaro?
Both are GLP-1-based weight loss injections, but Mounjaro (tirzepatide) is a dual GIP+GLP-1 agonist while Wegovy (semaglutide) is GLP-1 only. Clinical trials showed Mounjaro may produce slightly higher average weight loss, but both are effective. They have similar side effects and are both prescription-only. Choice depends on individual response and prescriber assessment.
Who is eligible for Wegovy in the UK?
Adults with BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions (diabetes, hypertension, cardiovascular disease, or sleep apnoea) may be eligible. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds per NHS guidance. A GP or licensed prescriber will assess your individual eligibility.
How do I get Wegovy privately in the UK?
Complete an online health assessment with a UK-licensed prescriber, provide medical history, and receive a prescription if approved (typically within 24–48 hours). The prescription is dispensed by a GPhC-registered pharmacy. Costs range from £129 to £320 monthly depending on your dose. No GP referral is needed for private access.
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.