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 Many Clicks In Mounjaro Pen?
Mounjaro doesn't work with clicks — instead, it uses a dose dial on the KwikPen device. This is a common question because people often confuse Mounjaro with other injection pens that do click. Understanding how your Mounjaro KwikPen works is essential for safe, accurate dosing. The pen is designed for once-weekly use, and the dial system makes it easy to select your prescribed dose. This guide explains exactly how to use your pen correctly and what to expect when you inject.
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.
How The Mounjaro KwikPen Dose Dial Works
The Mounjaro KwikPen uses a rotating dose dial instead of clicking increments. Here's how it works: The dial rotates to select your prescribed dose (2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, or 15 mg). The dial will only rotate in one direction and stops at your dose setting, preventing accidental overdosing. A click sound occurs when you press the injection button to deliver the dose, but this is not how you select the dose — the dial handles dose selection. Each KwikPen contains four pre-filled doses (a four-week supply). The dial resets after each injection, ready for your next weekly dose.
- Dial rotates to select dose before each injection
- One click sound when you press the button to inject
- Each pen contains four ready-to-use doses
- Dial stops at correct dose automatically
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.
Step-By-Step Injection Instructions
Prepare your injection by removing the pen from the fridge 15–30 minutes before use to warm it to room temperature. Check the medication inside the pen window — it should be clear and colourless. Hold the pen firmly and rotate the dose dial until your prescribed dose aligns with the dose indicator window. Pinch the skin at your injection site (stomach, thigh, or upper arm) and insert the needle at a 90-degree angle. Press the injection button down firmly until you hear and feel a click — hold for three seconds to ensure the full dose is delivered. Withdraw the needle and release the pinched skin. Dispose of your used pen in a sharps bin. After each injection, the dial resets automatically for next week's dose.
- 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.
Why doesn't my Mounjaro pen have clicks for dosing?
Mounjaro uses a dose dial system, not clicks. The dial rotates to select your dose (2.5 mg to 15 mg) and stops automatically at the correct setting. You may be thinking of other injection pens that use click increments. The Mounjaro KwikPen's dial design prevents dosing errors and makes it safer and easier to use.
How do I know if I've injected the full dose?
You'll hear and feel a click when you press the injection button. Hold the button down for three seconds after the click to ensure the complete dose is delivered. The needle will remain in your skin during this time. Once released, the dose dial automatically resets for your next weekly injection.
Can I rotate the dose dial backwards if I make a mistake?
No. The Mounjaro KwikPen dial only rotates in one direction. If you rotate past your prescribed dose by mistake, you cannot go backwards. You'll need to start with a new pen. Always check your dose setting carefully before injecting, or ask your pharmacist to confirm your dose.
What if my Mounjaro dose needs to increase — does the dial change?
No, the dial doesn't change. Your GP or prescriber will adjust your dose every 4 weeks during the titration phase (weeks 1–20). You'll receive a new prescription for the higher dose, and your pharmacy will dispense a new KwikPen with the dial set for that dose. Never attempt to self-adjust your dose.
Is the Mounjaro KwikPen different from Wegovy pens?
Yes. Mounjaro (tirzepatide) uses a dose dial, while Wegovy (semaglutide) uses a dose-selector button. Both are once-weekly injections, but the delivery mechanisms are different. Always follow the specific instructions for your prescribed medication. If you're unsure how to use your pen, ask your pharmacist or GP.
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.