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
Where To Get Mounjaro In The UK
Getting Mounjaro (tirzepatide) in the UK depends on which route you choose — NHS specialist services or private prescribing. Both require a clinical assessment before a UK-licensed prescriber will issue a prescription. The NHS route is free but often involves waiting lists, whilst private online prescribing is typically faster but involves costs. Understanding both pathways helps you decide which option suits your situation best.
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.
NHS Access To Mounjaro — What To Expect
Mounjaro is available through the NHS as part of specialist tier 3 and tier 4 weight management services. You cannot get it from your GP surgery directly — referral to a specialist weight management service is the first step. Your GP can refer you if you meet eligibility criteria: a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. South Asian, Chinese, Black African, and Black Caribbean adults may be eligible at lower BMI thresholds.
The NHS pathway is free once prescribed, but waiting lists vary significantly by region and ICB (Integrated Care Board). In some areas, waiting times can be several months to over a year. Once referred, the specialist service will conduct a full assessment including blood tests, medical history review, and lifestyle evaluation before deciding if Mounjaro is appropriate for you.
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 Prescribing — Faster Access Route
Private online prescribing offers faster access to Mounjaro without waiting for NHS referral. You complete an online health questionnaire and video or telephone consultation with a UK-licensed prescriber. If approved, a prescription is issued and dispensed by a GPhC-registered pharmacy. Costs typically range from £129–£320 per month depending on the dose and provider.
This route requires personal payment but avoids NHS waiting lists. All prescribers conduct a clinical assessment to ensure Mounjaro is safe for you — private prescribing still requires genuine medical evaluation, not a simple online checkout. Results vary individually, and this medication works best alongside a reduced-calorie diet and increased physical activity.
- 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 I get Mounjaro from my GP on the NHS?
No — Mounjaro is not available for standard GP prescription. You must be referred to a specialist tier 3 or tier 4 weight management service. Your GP can make the referral if you meet criteria (BMI 30+ or 27+ with health conditions), but the specialist team will conduct the assessment and prescribe if suitable.
How long are NHS waiting lists for Mounjaro?
Waiting times vary significantly by region. Some areas have waits of several months; others exceed a year. Check with your local ICB or ask your GP which weight management services are available in your area and what current waiting times are.
Is private Mounjaro prescribing genuinely safer than other routes?
Private UK prescribers are licensed and regulated by the MHRA and GPhC just like NHS prescribers. The key difference is speed, not safety — private prescribing still involves proper clinical assessment. Ensure any provider you use is GPhC-registered and requires a legitimate consultation.
What happens at a specialist weight management service assessment?
You'll have a full medical evaluation including blood tests, BP check, detailed medical history, and discussion of lifestyle and previous weight loss attempts. The team assesses whether Mounjaro is appropriate for your situation and discusses realistic goals. Assessment takes 1–3 hours typically.
Can I switch from NHS to private Mounjaro prescribing?
Yes — if you're waiting for NHS access or prefer private prescribing, you can pursue the private route independently. If you later wish to switch to NHS prescribing, inform your GP. Costs, continuity, and prescriber communication should all be considered in your decision.
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.