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
Mounjaro Rules: How to Access and Costs in the UK
Understanding Mounjaro eligibility and how to access tirzepatide in the UK requires knowing both NHS and private routes. Mounjaro is a prescription-only GIP and GLP-1 receptor agonist injection available through specialist services or private online prescribing. This guide explains UK rules for eligibility, costs, and the clinical assessment process you'll need to complete before being prescribed this weight management medicine.
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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.
UK Private Access Costs and How to Get Mounjaro
Private prescription access is the fastest way to get Mounjaro in the UK. Following an online clinical consultation with a UK-licensed prescriber, a prescription can typically be issued within 24 hours if you're assessed as clinically suitable. Private costs vary by dose but generally range from £129 to £320 per month, depending on which tier you're prescribed and the private provider.
Key cost factors include: the starting dose (2.5 mg is cheaper than titrated doses), whether you're buying a single pen or a month's supply, and private clinic pricing. Each KwikPen contains 4 doses covering one month. Most private services offer flexibility to pause, change dose, or stop treatment — though cancellation and refund policies vary. Always check terms before purchasing. Online consultations typically cost between £50 and £150, though some providers include this in the first prescription cost.
- Starting dose (2.5 mg): approximately £129–£160 per pen
- Mid-range doses (5–10 mg): approximately £180–£240 per pen
- Maximum dose (15 mg): approximately £280–£320 per pen
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 Access vs Private: Rules and Timelines
NHS access to Mounjaro is free but involves significant waiting times and regional variation. NICE has approved tirzepatide for NHS use, but access depends on your ICB (Integrated Care Board) and tier 3/4 specialist weight management services availability. Most areas have waiting lists of 6–18 months. You'll need a GP referral and assessment showing you meet strict BMI and health criteria — typically BMI 30 or above, or BMI 27–29.9 with weight-related conditions like type 2 diabetes or cardiovascular disease.
Private online prescribing skips NHS waiting lists but requires you to pay full cost. The clinical assessment process is similar in both routes: questions about medical history, current medications, previous weight loss attempts, and lifestyle. Use our GLP-1 weight loss calculator to estimate potential outcomes at different doses, and track progress with our free progress tracker once you start treatment.
NHS route: Free medication but 6–18 month wait. GP referral required. Available through specialist tier 3 services only. Regional variation in availability.
Private route: Fast access (24–48 hours) but full cost £129–£320/month. Online consultation required. No NHS waiting list. Payment upfront. More flexibility to adjust or stop treatment.
Eligibility rules are the same for both: BMI 30+ (or 27+ with weight-related health conditions), adults 18+, not pregnant or breastfeeding, no allergy to tirzepatide, no severe gastroparesis history. Our BMI calculator can help you check if you meet baseline eligibility criteria before pursuing either 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.
What is the typical cost of Mounjaro per month in the UK privately?
Private Mounjaro costs range from approximately £129–£320 per month depending on dose. Starting dose (2.5 mg) is around £129–£160. Mid-range doses (5–10 mg) cost £180–£240. Maximum dose (15 mg) is approximately £280–£320. Prices vary between private providers. Online consultation adds £50–£150 but some providers include this in the first prescription cost.
How long does it take to get Mounjaro on the NHS?
NHS waiting times for Mounjaro typically range from 6–18 months, depending on your region and local specialist weight management service capacity. Access requires a GP referral and assessment through tier 3 specialist services. Availability and waiting lists vary significantly across different ICBs (Integrated Care Boards) in the UK.
Do I need to meet specific eligibility rules to access Mounjaro?
Yes. You must be an adult 18+, with a BMI of 30 kg/m² or above, or BMI 27–29.9 with at least one weight-related health condition (type 2 diabetes, hypertension, cardiovascular disease, etc.). You cannot be pregnant, breastfeeding, or allergic to tirzepatide. A prescriber will assess suitability based on your individual health during consultation.
What's the difference between NHS and private Mounjaro access?
NHS access is free but involves long waiting lists (6–18 months) and requires GP referral to specialist services. Private access is faster (24–48 hours) but costs £129–£320/month. Both routes require clinical assessment. Private offers more flexibility to adjust doses or stop, while NHS access is region-dependent.
What should I expect during an online clinical consultation for Mounjaro?
An online consultation involves discussing your medical history, current medications, weight loss attempts, lifestyle, diet, and exercise. The prescriber will ask about diabetes, heart conditions, kidney function, and gastroparesis history. They'll review your BMI and health conditions to assess suitability. If approved, a prescription is typically issued within 24 hours and dispensed by a GPhC-registered pharmacy.
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.