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 Does Wegovy Do and How Can You Access It in the UK?
Wegovy (semaglutide) is a once-weekly GLP-1 receptor agonist injection licensed in the UK for weight management in adults. It works by mimicking a natural hormone that helps regulate appetite, reduce food cravings, and support feeling fuller after smaller meals. Understanding how Wegovy works, what it costs, and how to access it — whether through the NHS or private prescription — is essential for anyone considering this medication as part of their weight management journey.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
How Much Does Wegovy Cost in the UK and Where to Get It?
Wegovy is available in the UK through two main routes: NHS specialist weight management services and private online prescription services. The route you choose affects both cost and access speed.
Private prescription costs typically range from £120 to £300 per month, depending on your starting dose (0.25 mg) and maintenance dose (up to 2.4 mg). Most private prescribing services offer flexible payment, with costs calculated per injection pen — each pen contains 4 weekly doses. Your dose may increase gradually over several months, meaning initial costs are lower before reaching your maintenance dose.
NHS access is through tier 3 specialist weight management services via GP referral. There is no medication cost to you on the NHS, but availability varies significantly by region, and waiting lists can extend many months. Eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes or high blood pressure. Use our free GLP-1 weight loss calculator to understand potential outcomes, and our BMI calculator to check your eligibility threshold.
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: Which Route Is Right for You?
NHS route: Medically supervised, no cost, but long waiting lists in many areas. You must be referred by your GP to a specialist service, and they will assess whether Wegovy or another weight loss option suits you. This route is ideal if you prefer NHS oversight and have time to wait.
Private route: Faster access (days to weeks), flexible dosing, no waiting list, but you pay full cost. A UK-licensed prescriber conducts an online clinical assessment, checks your medical history, and issues a prescription if appropriate. A GPhC-registered pharmacy then dispenses your medication. This route suits those wanting quicker access and who can manage the cost. Whichever route you choose, track your progress with our free progress tracker to monitor your weight loss journey and stay motivated.
- 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.
How much does a Wegovy prescription cost privately in the UK?
Private Wegovy costs typically range from £120 to £300 per month depending on your dose. Starting doses (0.25 mg) cost less than maintenance doses (2.4 mg). Costs are usually charged per 4-week pen supply. Most private prescribing services offer flexible payment plans, and some offer subscription discounts for ongoing treatment.
Can I get Wegovy on the NHS in the UK?
Yes, Wegovy is available on the NHS through specialist tier 3 weight management services. You must be referred by your GP and meet eligibility criteria (BMI 30+, or 27–29.9 with weight-related health conditions). There is no medication cost, but waiting lists are often long — sometimes several months depending on your region and local ICB capacity.
What is the difference between Wegovy and Mounjaro in the UK?
Both are GLP-1-based weight loss injections, but Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, while Wegovy (semaglutide) is a GLP-1 receptor agonist only. In clinical trials, Mounjaro showed slightly higher average weight loss (~21%) compared to Wegovy (~15%), though individual results vary significantly. Both are prescription-only and available through NHS specialist services or private prescription.
How quickly can I get Wegovy if I pay privately?
Private prescription turnaround is typically 3–7 days from online consultation to medication delivery. You complete an online health questionnaire, a UK-licensed prescriber reviews your medical history, and if approved, your prescription is sent to a GPhC-registered pharmacy for dispensing. This is much faster than NHS routes, where waiting lists can extend many months.
What dose of Wegovy would I start on?
Wegovy starts at 0.25 mg once weekly for the first 4 weeks, then escalates gradually — 0.5 mg, 1 mg, 1.7 mg, and finally 2.4 mg maintenance dose. Escalation takes approximately 16–20 weeks. Your prescriber may adjust your escalation speed based on side effects or response. A clinical assessment will determine the right starting point 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.