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
Can GPs Prescribe Mounjaro in the UK?
GPs cannot typically prescribe Mounjaro through routine NHS services. Prescription tirzepatide (the active ingredient in Mounjaro) is available through specialist weight management services or private prescription following a clinical assessment. Access routes differ significantly between NHS and private pathways, each with different timescales and costs. Understanding your options helps you make an informed choice about how to access this weight loss medication in the UK.
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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.
NHS vs Private Access to Mounjaro
NHS access: Mounjaro (tirzepatide) is approved by NICE for use within NHS specialist weight management services, but it is not available through routine GP prescriptions. Your GP must refer you to a tier 3 or tier 4 specialist service — often a hospital-based weight management clinic. These services provide comprehensive assessment, monitoring, and ongoing support. However, NHS availability varies dramatically by region. Some areas have dedicated tirzepatide pathways, whilst others have long waiting lists or limited access. Your GP can advise on what is available in your locality.
Private access: You can obtain a private prescription for Mounjaro through an online consultation with a UK-licensed prescriber. No NHS referral is needed. Once approved, your prescription is dispensed by a GPhC-registered pharmacy. This route is faster — typically within days — but you pay the full cost. Private prescriptions for tirzepatide generally range from £129 to £320+ per month depending on dose, with ongoing costs for dispensing and follow-up consultations.
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.
Private Prescription Cost & What to Expect
Private Mounjaro costs vary by supplier and dose. Starting doses (2.5 mg) are typically less expensive than maximum doses (15 mg). Most private providers charge per dose or per month, with prices ranging from approximately £129 for lower doses to £300+ for higher doses. You will also need follow-up consultations, usually £20–£50 per check-in. Some providers offer subscription plans that bundle medication and consultations. Before starting, confirm what ongoing monitoring is included — regular blood pressure and blood sugar checks may be recommended. Use our GLP-1 weight loss calculator to explore potential outcomes at different dose levels, and our BMI calculator to check your starting point.
NHS specialist services: If referred to an NHS service, tirzepatide is typically free once approved, but you may wait weeks or months for assessment. NHS services provide structured support including dietician input and regular clinical monitoring. Private online route: Faster access (days), but you pay full cost. The prescriber assesses your BMI, health history, and weight-related conditions via online questionnaire and video consultation. If approved, medication is sent to your address or collected from a pharmacy. You manage your own dose escalation schedule, though prescribers provide guidance. Some private services include follow-up consultations; others charge separately.
- 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.
Can my GP prescribe Mounjaro directly?
Not routinely. Your GP would need to refer you to a specialist weight management service. In some cases, GPs may manage ongoing care following specialist initiation, but initial prescription typically comes through tier 3 or tier 4 specialist services, not routine GP appointment.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £129 to £320+ per month depending on dose and supplier. Additional costs include consultation fees (£20–£50) and follow-up appointments. Prices vary between providers, so it's worth comparing costs before committing.
How do I get a private prescription for Mounjaro?
Complete an online consultation form with a UK-licensed prescriber, usually via an online healthcare provider. You'll answer health questions about your BMI, medical history, and weight-related conditions. If approved, a prescription is issued and dispensed by a GPhC-registered pharmacy to your address.
What's the difference between NHS and private Mounjaro?
NHS access is free but involves waiting lists and specialist referral. Private access is faster (days) but you pay full cost. NHS includes structured support and monitoring; private routes vary by provider. Both provide the same medication (tirzepatide) and require clinical assessment.
Is Mounjaro available on the NHS now?
Yes, NICE has approved tirzepatide for NHS weight management services. However, availability varies by region and demand often exceeds supply, leading to waiting lists. Check with your GP about tier 3 services in your area to understand realistic access timescales.
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.