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
How to Get a Private Mounjaro Prescription in the UK
Getting Mounjaro privately in the UK is faster than waiting for NHS specialist services, but requires a clinical assessment from a UK-licensed prescriber. Private prescriptions are available through GPhC-registered online pharmacies without a GP referral. You'll need to meet specific eligibility criteria based on BMI and health conditions. This guide explains how the private prescription process works, what it costs, and how it compares to NHS access. Use our free BMI calculator above to check your current BMI before starting the process.
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.
Understanding Private vs NHS Mounjaro Access in the UK
NHS access to Mounjaro (tirzepatide) is through tier 3 specialist weight management services. Your GP refers you to a specialist service, which assesses your eligibility and prescribes Mounjaro if appropriate. This is free but involves significant waiting lists in many regions — some areas have delays of several months or longer. NICE has approved tirzepatide for NHS use, but availability depends on your local Integrated Care Board (ICB) and service capacity.
Private access is faster. You have a brief online clinical assessment with a UK-licensed prescriber (usually a GP or nurse), answer health questions, and receive a prescription within hours if approved. The prescription is dispensed by a GPhC-registered pharmacy. No GP referral is needed. Your Mounjaro KwikPen arrives with full guidance and NHS-aligned dosing (starting at 2.5 mg, titrating up to 15 mg over weeks).
- NHS route: free but long waiting lists
- Private route: £129–£320 per month depending on dose
- Both routes use identical medication and MHRA-approved protocols
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.
Eligibility Criteria and the Private Prescription Process
You're eligible for a private Mounjaro prescription if you have a BMI of 30 kg/m² or above, or a BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, prediabetes, high blood pressure, or cardiovascular disease. For South Asian, Chinese, Black African, and Black Caribbean adults, lower thresholds apply — eligibility may start at BMI 27.5 or above due to higher health risks at lower weights.
The private assessment process is straightforward: you complete a health questionnaire online, provide height and weight (check your measurements with our free weight converter), and disclose any medications or contraindications. If approved, your prescription is issued. You cannot get a private Mounjaro prescription if you're under 18, pregnant, breastfeeding, or have severe gastroparesis. Always inform the prescriber of all medications — Mounjaro may affect oral contraceptive absorption.
Private Mounjaro costs vary by dose and provider, ranging from approximately £129 per month for the starting dose (2.5 mg) to £280–£320 per month at the maximum dose (15 mg). Most people spend 4 weeks at each dose level before titrating up, so initial treatment is lower-cost. Some private providers offer subscription discounts or multi-month packages. Track your progress with our free progress tracker to monitor weight loss alongside your injection schedule. The dose is adjusted based on your tolerance and response — if you experience significant side effects, your prescriber may recommend staying at a lower dose longer.
- 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 switch from NHS Mounjaro to private, or vice versa?
Yes, you can switch between NHS and private routes at any time. If you've been receiving Mounjaro privately and want to move to NHS, you'd need to be referred to a tier 3 service by your GP. Conversely, if you're on an NHS waiting list and want to start privately instead, you can do so immediately. Your prescriber can advise on continuing your current dose when switching routes.
How quickly will I receive Mounjaro with a private prescription?
Once approved, most private pharmacies dispatch Mounjaro within 1–3 working days. You receive your KwikPen with injection instructions, storage guidance (refrigerate at 2–8°C until use), and contact details for the pharmacy if you have questions. Express delivery options are sometimes available for an additional fee.
What health conditions qualify me for Mounjaro eligibility with a BMI of 27–29.9?
The NHS and private prescribers recognise type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats (dyslipidaemia), obstructive sleep apnoea, and a history of heart attack or stroke. Other significant weight-related conditions may also qualify — the prescriber will assess your individual situation during your clinical assessment.
Is the private Mounjaro prescription the same medication as NHS Mounjaro?
Yes, completely. The active ingredient (tirzepatide), dose range (2.5–15 mg), and injection schedule are identical. Both use the KwikPen device and follow MHRA-approved protocols. The only difference is the route of access — NHS is free but involves waiting; private is quicker but costs £129–£320 per month depending on dose.
Do I need my GP's permission to get a private Mounjaro prescription?
No. Private prescriptions are independent of NHS care. You don't need your GP's referral or permission. However, it's good practice to inform your GP that you're starting Mounjaro privately so they're aware of your treatment and can monitor your health appropriately during routine appointments.
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.