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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How Many Clicks on a Mounjaro KwikPen — UK Guide
The Mounjaro KwikPen is a simple, pre-filled injection device that delivers your tirzepatide dose automatically. Each click on the pen represents 0.1 mg of medication, and your prescriber will tell you exactly how many clicks to use based on your dose. Understanding your pen and how to use it correctly is essential for safe, effective treatment. This guide explains the click system, dose progression, and what to expect when using Mounjaro in the UK.
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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 the Mounjaro KwikPen Click System Works
The Mounjaro KwikPen uses a dial-and-click mechanism. Each full rotation of the dose dial produces one click, which delivers 0.1 mg of tirzepatide. Your pen will show your prescribed dose when you line up the dose counter with the injection needle on the side of the pen.
Click numbers for each dose:
- 2.5 mg dose = 25 clicks
- 5 mg dose = 50 clicks
- 7.5 mg dose = 75 clicks
- 10 mg dose = 100 clicks
- 12.5 mg dose = 125 clicks
- 15 mg dose = 150 clicks
Your prescriber or pharmacy will confirm how many clicks you need before you start. Always check the dose counter on your pen matches your prescription. If you are unsure, contact your prescriber or pharmacist before injecting.
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 vs Private Access — Cost and Getting Mounjaro in the UK
NHS access: Mounjaro is available through specialist tier 3 weight management services in some NHS areas, though regional availability varies significantly. You would need referral from your GP to a specialist service, and prescribing follows NHS pathways.
Private access: Mounjaro is available through GPhC-registered online prescription services following a remote clinical assessment. Costs typically range from £150–£300 per month depending on your dose, with each KwikPen containing four weeks of injections. Using our free GLP-1 weight loss calculator can help you estimate potential results and costs at different doses, making it easier to understand the investment.
The online prescription route is faster than NHS waiting lists in most areas. You complete a health questionnaire, a UK-licensed prescriber reviews your details, and if approved, your prescription is sent to a pharmacy which dispatches your pens. Most people receive their first delivery within 3–7 days. Remember that Mounjaro works alongside lifestyle changes—reduced calories and increased activity—rather than replacing them.
- 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 if I accidentally click more than my dose on the Mounjaro pen?
If you accidentally dial past your dose, you can turn the dial backwards to return to the correct number. Never attempt to inject twice or use more than prescribed. Contact your pharmacist or prescriber if you are unsure about your dose.
How often do I inject Mounjaro and why is the click system important?
Mounjaro is injected once weekly, always on the same day. The click system is important because it ensures you receive the precise dose prescribed by your doctor. Incorrect clicks could mean you receive too much or too little medication, affecting both safety and results.
Does the number of clicks change when I increase my dose?
Yes. Your prescriber will adjust your dose every 4 weeks during the initial phase. As you progress through the dose titration schedule, the number of clicks increases. Each time your dose changes, your prescriber or pharmacy will confirm your new click count.
Can I get Mounjaro prescribed through my GP in the UK?
Most GPs do not prescribe Mounjaro directly for weight management. NHS prescriptions go through specialist tier 3 weight management services. Private prescription is available through online clinical assessment services. Your GP can discuss referral options for NHS specialist services if appropriate.
What does BMI have to do with Mounjaro eligibility?
Mounjaro eligibility in the UK is partly based on your BMI. Adults with a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions, may be eligible. Use our free BMI calculator above to check your BMI instantly and understand where you fall on the eligibility scale.
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.