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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Private Prescription for Mounjaro in the UK
If you're considering Mounjaro (tirzepatide) for weight management, you have two pathways in the UK: NHS specialist services or private prescription. A private prescription for Mounjaro allows you to access this once-weekly injection without waiting for NHS referral, though it does involve direct costs. This guide explains how private prescriptions work, eligibility requirements, and what to expect when pursuing this route.
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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.
How Private Mounjaro Prescriptions Work in the UK
A private prescription for Mounjaro is issued by a UK-licensed prescriber following an online clinical assessment. Unlike NHS access through tier 3 specialist weight management services, private prescriptions are available without waiting lists or regional availability issues. The process typically involves:
- Completing an online health questionnaire
- Consultation with a licensed prescriber (usually by video or secure messaging)
- Prescription issued if clinically appropriate
- Dispensed by a GPhC-registered online pharmacy
The Mounjaro KwikPen you receive is identical to NHS-dispensed pens — it's the same prescription-only medication manufactured by Eli Lilly. Private prescriptions are renewed through follow-up assessments, typically every 3–12 months depending on the provider. Costs vary but typically range from £129–£320 per month depending on your dose. The starting dose is 2.5 mg, escalating to a maximum of 15 mg weekly.
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 and What You'll Need
Private prescribers assess eligibility using similar criteria to NHS services. You may be eligible for a private Mounjaro prescription if you have a BMI of 30 kg/m² or above, or BMI 27–29.9 with weight-related health conditions such as type 2 diabetes, hypertension, or sleep apnoea. You'll need to provide medical history, current medications, and be honest about any contraindications. Those under 18, pregnant, breastfeeding, or with certain medical conditions may not be eligible. Use our free BMI calculator above to check where you currently stand, and our GLP-1 weight loss calculator to estimate potential weight loss outcomes at different Mounjaro doses.
- 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 a private Mounjaro prescription the same medication as NHS Mounjaro?
Yes, completely. The tirzepatide in Mounjaro KwikPens is identical regardless of whether prescribed privately or through NHS services. It's the same manufacturer, same strength, same effectiveness. The only difference is the pathway and cost.
How much does a private Mounjaro prescription cost in the UK?
Costs vary between providers but typically range from £129–£320 per month depending on your dose. Starting doses (2.5 mg) are usually at the lower end; maximum doses (15 mg) at the higher end. Some providers offer package discounts for longer commitments.
How long does it take to get a private Mounjaro prescription?
Most private providers can issue a prescription within 24–72 hours of your assessment. This is significantly faster than NHS routes, which can involve waiting lists of months to over a year in some regions depending on your local integrated care board.
Can I switch from private Mounjaro to NHS Mounjaro?
This varies by region and NHS policy. Some NHS services may accept patients already stabilised on Mounjaro; others require starting from the beginning. Contact your local tier 3 weight management service to ask about their policy on switching from private to NHS care.
What's the difference between private Mounjaro and Wegovy prescriptions?
Both are prescription-only weight management injections available privately in the UK. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist; Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials show both can support weight loss, though individual results vary. Your prescriber will help determine which is more suitable.
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.