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
When Was Mounjaro Released in the UK?
Mounjaro (tirzepatide) received UK regulatory approval in 2023, making it available for weight management in adults across the country. The medication became accessible through both NHS specialist services and private online prescribing routes. Understanding when Mounjaro was released helps context the rapid growth of prescription weight loss options in the UK. Access and cost vary significantly depending on which route you choose—NHS or private—and your individual eligibility criteria.
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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.
Cost and Access Routes for Mounjaro in the UK
Private prescription route: Mounjaro is available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. Private costs typically range from £129 to £320 per month depending on your dose, with the KwikPen containing a 4-week supply. Doses start at 2.5 mg and escalate gradually to a maximum of 15 mg weekly. You can access private prescribing without waiting for NHS referral, though availability and pricing vary between providers.
NHS route: Access through specialist tier 3 weight management services requires referral from your GP. NICE has approved tirzepatide for NHS use, but availability varies significantly by region and ICB (Integrated Care Board). Many areas have substantial waiting lists—sometimes months to years. NHS prescription is free once approved, but access is limited and typically reserved for those with BMI ≥30 or BMI 27–29.9 with weight-related health conditions. Check your local NHS weight management services for current availability.
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?
The NHS route offers free prescription once approved but involves GP referral, specialist assessment, and potential waiting lists. The private route is faster—you can access a UK-licensed prescriber within days—but requires payment. Online consultations assess your medical history, current medications, and suitability for Mounjaro before prescription. Both routes require genuine clinical assessment; neither is available without medical review. Your choice depends on your budget, timescale, and local NHS availability. Compare Mounjaro with alternatives like Wegovy to understand your options. Our GLP-1 weight loss calculator can help estimate potential outcomes at different doses alongside your chosen access route.
- 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.
When exactly was Mounjaro approved in the UK?
Mounjaro received MHRA approval in 2023 for weight management in adults. The medication became available through both NHS specialist services and private prescribing. Exact approval dates vary by route—private online prescribing became available before widespread NHS rollout due to regional service variation.
What does Mounjaro cost on the NHS?
Mounjaro is free on the NHS once prescribed through a specialist weight management service. However, availability is limited and varies by region. Many areas have waiting lists. You must be referred by your GP and meet eligibility criteria (BMI ≥30 or ≥27 with weight-related conditions).
How much does private Mounjaro cost per month?
Private Mounjaro typically costs between £129 and £320 per month depending on your dose and provider. Each KwikPen contains a 4-week supply. Starting dose is 2.5 mg; doses escalate gradually to a maximum of 15 mg weekly. Costs increase with higher doses.
How long does it take to get Mounjaro privately?
Private online prescribing is typically fast—you can complete a consultation within days and receive your first KwikPen within 1–2 weeks. NHS access is much slower, often involving months-long waiting lists for specialist tier 3 weight management services depending on your region.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist; Wegovy (semaglutide) is GLP-1 only. Mounjaro has a maximum dose of 15 mg weekly; Wegovy reaches 2.4 mg. Clinical trials suggest Mounjaro may offer slightly greater average weight loss, though individual results vary significantly. Both are prescription-only.
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.