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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Mounjaro Clicks Chart and Dose Titration in the UK
The Mounjaro KwikPen delivers tirzepatide in precise weekly doses, with each "click" or dose level marking a specific injection strength. In the UK, understanding how the clicks system works is essential for anyone considering this prescription-only weight management medication through NHS specialist services or private prescribing. This guide explains the dose progression, eligibility criteria, and how Mounjaro fits into the UK healthcare landscape.
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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 Eligibility and Dose Progression in the UK
Mounjaro is a prescription-only GIP and GLP-1 receptor agonist available in the UK for weight management in adults. The KwikPen contains four pre-filled doses, each delivered via a single weekly injection. The standard UK dose progression follows a four-week escalation schedule:
- Weeks 1–4: 2.5 mg (starting dose)
- Weeks 5–8: 5 mg (first escalation)
- Weeks 9–12: 7.5 mg
- Weeks 13–16: 10 mg
- Weeks 17–20: 12.5 mg
- Week 21+: 15 mg (maximum dose)
NICE guidance supports tirzepatide for use within NHS specialist weight management services (tier 3) for adults with 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 cardiovascular disease. Lower BMI thresholds apply for South Asian, Chinese, Black African, and Black Caribbean adults due to higher metabolic risk at these thresholds. Your prescriber will assess whether dose escalation is appropriate based on your response and tolerability.
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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 vs Private Routes and Practical Considerations
In the UK, Mounjaro is accessed via two main routes. NHS access is through specialist tier 3 weight management services following GP referral—availability varies significantly by region and waiting lists can be lengthy. Private access is through GPhC-registered online pharmacies following a remote clinical assessment, without requiring NHS referral. Whichever route you choose, a licensed prescriber will determine your starting dose and escalation schedule based on your individual health profile. Clinical trials showed that patients on 15 mg tirzepatide achieved average weight loss of approximately 20.9% body weight, though individual results vary considerably. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses, and our BMI calculator to establish your baseline health context.
- 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 does "clicks" mean with the Mounjaro KwikPen?
Each pre-filled dose in the KwikPen is sometimes referred to as a "click" in clinical practice—this is simply user terminology for the rotating mechanism that delivers each weekly injection. Each KwikPen contains four weeks of doses (four "clicks"), after which you dispose of the pen and start a new one. The term is informal; your prescriber will refer to doses in milligrams (2.5 mg, 5 mg, etc.).
How long does it take to reach the maximum Mounjaro dose in the UK?
Following the standard NHS and private prescribing protocol, it takes approximately 20–21 weeks to reach the maximum 15 mg dose, assuming four-week intervals at each escalation step. However, prescribers may adjust this timeline based on your tolerability and individual response. Some people remain on lower maintenance doses if they achieve their health goals or experience side effects.
Is Mounjaro available on the NHS, and how do I access it?
Yes, NICE has approved tirzepatide (Mounjaro) for NHS use within specialist tier 3 weight management services. You'll need a GP referral to a local specialist weight management service. Availability varies by region (ICB), and waiting times can be substantial. Private access via online prescribing is an alternative route that doesn't require NHS referral.
What's the difference between Mounjaro and Wegovy in terms of UK prescribing?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist with a maximum dose of 15 mg weekly, whilst Wegovy (semaglutide) is a GLP-1-only agonist with a maximum dose of 2.4 mg weekly. Both are prescription-only in the UK. Clinical trial data shows Mounjaro achieved slightly higher average weight loss (~21%) compared to Wegovy (~15%), though individual responses vary significantly.
Who is not eligible for Mounjaro in the UK?
Mounjaro is not suitable for under-18s, pregnant or breastfeeding women, people with a history of medullary thyroid cancer, those with multiple endocrine neoplasia syndrome type 2, or anyone with a known allergy to tirzepatide. Your prescriber will conduct a full clinical assessment to confirm eligibility before prescription.
Ready to take control of your weight loss journey?
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