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 a Mounjaro 5mg KwikPen?
The Mounjaro KwikPen doesn't use clicks—it's a single-dose pre-filled injection device. The 5mg dose is delivered as one complete weekly injection. If you're comparing Mounjaro to Wegovy or wondering about dosing mechanisms, this guide explains how the Mounjaro pen works, how it differs from other weight loss injections available in the UK, and what to expect when using this prescription medication.
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.
Mounjaro KwikPen vs Wegovy Pen: How They Work
Mounjaro KwikPen delivery: The Mounjaro pen is a pre-filled, single-dose device. Each week, you use one complete pen containing your prescribed dose (2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, or 15mg). There are no adjustable clicks or dose increments—you simply press and hold the injection button until the pen signals completion, typically 3–10 seconds. The entire dose is delivered in one injection.
- Each KwikPen contains exactly one dose for one week
- Colour-coded pens match dose strength for easy identification
- Auto-injector mechanism means no a UK pharmacy syringe handling
- You dispose of the pen after use
Wegovy pen comparison: Wegovy also uses a pre-filled pen (FlexTouch) with single-dose delivery, but doses are smaller (0.25mg to 2.4mg). Wegovy pens are also single-use, disposed of after injection. Both are tirzepatide (Mounjaro) and semaglutide (Wegovy) respectively—different active ingredients with different dosing schedules.
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.
Mounjaro Dose Titration and When Your Dose Changes
Mounjaro dose increases happen every 4 weeks. You start at 2.5mg (week 1), then move to 5mg (weeks 5–8), then potentially 7.5mg, 10mg, 12.5mg, or 15mg based on your prescriber's guidance and how your body responds. Each increase means using a new KwikPen with the higher dose—you don't adjust the same pen. When you reach your target maintenance dose (often 10mg or 15mg for most people), you continue with that same dose strength each week. Your prescriber will advise your personal titration schedule. Try our GLP-1 weight loss calculator to explore projected outcomes at different doses during your treatment journey.
- 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 Mounjaro 5mg the same as 5 clicks on the pen?
No. Mounjaro uses pre-filled KwikPens with fixed doses—there are no adjustable clicks. The 5mg dose is delivered as one complete injection per week. Each pen is single-use and pre-loaded with your exact prescribed dose.
Can I adjust the dose on my Mounjaro pen myself?
No. Mounjaro doses cannot be adjusted individually. Your prescriber determines your dose, and you receive a new pre-filled pen at each dose strength. Dose increases happen every 4 weeks under clinical guidance.
How long does a Mounjaro 5mg injection take?
A Mounjaro injection typically takes 3–10 seconds. You press the injection button and hold until the pen signals completion with a click or vibration. The entire process is quick and uses the auto-injector mechanism built into the KwikPen.
What's the difference between Mounjaro and Wegovy dosing?
Mounjaro (tirzepatide) uses weekly doses from 2.5mg to 15mg, starting at 2.5mg. Wegovy (semaglutide) uses weekly doses from 0.25mg to 2.4mg, starting at 0.25mg. Mounjaro is a dual GIP+GLP-1 agonist; Wegovy is GLP-1 only. Both require UK prescription and clinical assessment.
Can I get Mounjaro on the NHS in the UK?
Mounjaro access via NHS is through specialist tier 3/4 weight management services following clinical referral. NHS availability varies significantly by region. Private access is available through UK-licensed online prescribers following an online clinical assessment with a registered prescriber.
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.