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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Is Wegovy Or Mounjaro Better For Cost And Access In The UK?
Choosing between Wegovy and Mounjaro often comes down to cost, availability, and how you access them in the UK. Both are prescription-only GLP-1 and dual-action weight loss injections, but they differ significantly in price, NHS availability, and how quickly you can start treatment. This guide compares both options to help you understand the real costs and access routes available to UK adults.
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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.
UK Private Prescription Costs For Wegovy And Mounjaro
Wegovy (semaglutide) typically costs between £129 and £300 per month privately in the UK, depending on your dose. The starting dose (0.25 mg) is cheaper than the maintenance dose (2.4 mg). Most private prescriptions are arranged through online consultations with UK-licensed prescribers, dispensed by GPhC-registered pharmacies.
Mounjaro (tirzepatide) generally costs between £149 and £320 per month privately. Like Wegovy, cost varies by dose — the starting dose (2.5 mg) is lower than the maximum (15 mg). Clinical trial data shows Mounjaro may produce slightly larger average weight loss (~20.9% at 15 mg vs ~14.9% for Wegovy at 2.4 mg), though individual results vary significantly.
- Both require dose escalation over 16–20 weeks before reaching maintenance
- Monthly costs reflect your current dose, not the final dose
- Private prescriptions do not include GP appointments — only the medication itself
- No waiting lists — private access is typically within 1–2 weeks
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 Versus Private Routes And Online Consultations
On the NHS, both medications are available through specialist tier 3 weight management services, but access is severely restricted. You need a GP referral, specialist assessment, and often face waiting lists of 6–24 months depending on your region. NHS prescription costs are minimal (around £9.90 per prescription in England), but availability varies by Integrated Care Board.
Private online route is faster: you complete an online health questionnaire, have a brief consultation with a UK-licensed prescriber, and receive a prescription if clinically appropriate. No GP involvement needed. Our GLP-1 weight loss calculator can help you estimate potential weight loss at different doses, which may inform your prescriber discussion. Always ensure the prescriber is a registered UK healthcare professional and the pharmacy is GPhC-registered before paying.
- 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.
Is Mounjaro cheaper than Wegovy in the UK?
Pricing is similar — both typically range £129–£320 per month privately depending on dose. Mounjaro may cost slightly more at higher doses, but the difference is usually £10–20 per month. Your actual cost depends on which dose you're on, not the final dose. Compare specific prices with prescribers before committing.
Can I get Wegovy or Mounjaro through the NHS?
Yes, both are available on the NHS through specialist weight management services (tier 3). However, access requires a GP referral, specialist assessment, and waiting lists are typically 6–24 months depending on your region. NHS prescription costs are around £9.90 per item in England. Private access is much faster — usually 1–2 weeks.
What happens during an online consultation for weight loss injections?
You'll complete a health questionnaire covering your medical history, current medications, and weight loss goals. A UK-licensed prescriber reviews this and may ask follow-up questions via video or phone. If approved, they issue a prescription to a GPhC-registered pharmacy. The entire process typically takes 2–5 days.
Which is better — Wegovy or Mounjaro?
Neither is universally "better" — it depends on your health, eligibility, and preferences. Mounjaro is a dual GIP/GLP-1 agonist and showed slightly larger average weight loss in trials (~20.9% vs ~14.9%). Wegovy has longer real-world use data. Both require prescription and clinical assessment. Use our free BMI calculator to check your eligibility, then discuss options with a prescriber.
Will private prescription costs go down?
Unlikely in the near term. As demand increases and supply stabilises, prices may adjust slightly. NHS access may improve regionally over time, but waiting lists remain significant. If cost is a barrier, discuss with your GP about NHS referral or explore tier 2 weight management programmes first.
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.