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 Mounjaro 7.5 Equivalent to Wegovy? UK Cost & Access
Mounjaro (tirzepatide) 7.5 mg and Wegovy (semaglutide) are both prescription-only weight management injections available in the UK, but they work differently and have different equivalent doses. While Mounjaro 7.5 mg is sometimes compared to Wegovy 1.7 mg based on clinical efficacy, they are not directly interchangeable — any switch between medications requires prescriber assessment. Understanding the cost and access routes in the UK helps you explore whether either option is right for you. Both are available through NHS specialist services or private online prescribing.
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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 Cost & Access Routes for Both Medications
Mounjaro in the UK: Private prescription costs typically range from £150–£320 per month depending on dose and pharmacy. The 7.5 mg dose (weeks 9–12 of titration) usually costs £200–£280 per month via private prescribing. A Mounjaro KwikPen contains 4 doses (4 weeks' supply), so costs reflect one month of treatment. Access is through a UK-licensed prescriber following an online clinical assessment.
Wegovy in the UK: Private prescription costs range from £129–£299 per month depending on current dose. Wegovy 1.7 mg (approximate equivalent to Mounjaro 7.5 mg for efficacy) typically costs £180–£250 per month privately. A single pre-filled pen lasts 4 weeks (one injection weekly), making monthly costs straightforward to compare.
- Both medications require a valid UK prescription from a licensed prescriber
- Private prescriptions are issued after an online consultation assessing your BMI, health history, and eligibility
- Prescriptions are dispensed by GPhC-registered pharmacies — never directly from clinics or gyms
- Costs vary by dose, pharmacy, and any additional consultation fees
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: How to Access Each Route in the UK
NHS route: Both Mounjaro and Wegovy are available through NHS specialist tier 3 weight management services, but access is limited and varies significantly by region. You need a GP referral to a specialist service, which can involve waiting lists of several months to over a year in many areas. Once assessed by the specialist team, prescription costs are minimal (standard NHS dispensing fees apply). However, availability depends on your local Integrated Care Board (ICB) funding and capacity.
Private route: Online consultations with UK-licensed prescribers are available 7 days a week. The process typically takes 24–48 hours from consultation to prescription. You'll be asked about your weight, height, medical history, and current medications. If approved, your prescription is sent to a registered pharmacy for dispensing. Total costs include the consultation fee (typically £30–£50) plus the medication itself. This route offers faster access and no waiting lists but requires paying the full cost privately.
- 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 7.5 mg the exact same strength as Wegovy 1.7 mg?
Not exactly. Mounjaro 7.5 mg and Wegovy 1.7 mg are approximate clinical equivalents based on weight loss outcomes in trials, but they use different mechanisms — Mounjaro is a dual GIP/GLP-1 agonist, Wegovy is GLP-1 only. Any medication switch must be managed by your prescriber and cannot be done directly.
Which is cheaper — Mounjaro or Wegovy in the UK?
Costs are generally similar at equivalent doses (£150–£300/month privately), but vary by pharmacy and dose. Wegovy's lower starting doses cost less initially. Mounjaro typically costs more at higher doses. Request quotes from multiple private prescribers to compare. NHS access eliminates cost but involves waiting lists.
Can I switch from Mounjaro 7.5 mg to Wegovy without medical advice?
No. Any switch between weight loss medications must be approved and managed by your GP or prescriber. They will consider your current dose, response, and side effects before recommending any change. Direct switching is not safe and could affect your treatment outcomes.
How long does it take to get a private prescription for Wegovy or Mounjaro?
Online consultations typically take 24–48 hours from booking to prescription issuance. Once issued, your pharmacy dispenses within 1–3 working days. NHS specialist assessment can take weeks to months depending on your local service. Total time varies significantly between private and NHS routes.
What's included in the private prescription cost for these injections?
Private costs cover the consultation fee (£30–£50) and the medication itself (£150–£320/month depending on dose and pharmacy). Some providers include follow-up consultations, but check your provider's policy. Prescriptions can be repeated monthly without additional consultation fees at many providers, though annual health checks are standard.
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.