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 in a 10mg Mounjaro Pen?
A 10mg Mounjaro KwikPen contains a single pre-filled dose that delivers exactly 10mg of tirzepatide in one injection — there is no "clicking" involved in the traditional sense. The KwikPen is a pre-measured auto-injection device, meaning the full 10mg dose is already prepared and ready to inject. This page explains how the pen works, how to access Mounjaro in the UK, and what you can expect regarding cost and the prescription process.
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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.
How the Mounjaro KwikPen Works and UK Prescription Access
The Mounjaro KwikPen is a pre-filled injection device manufactured by Eli Lilly. Each pen contains a single, ready-to-use dose of tirzepatide. Unlike some older injection systems, the KwikPen does not require a UK pharmacy dose selection or multiple clicks — it delivers the full dose automatically when activated.
Each box of Mounjaro contains 4 pre-filled pens, which is a 4-week supply since the medication is injected once weekly. A 10mg dose comes as a complete pen; you do not need to measure or adjust anything.
In the UK, Mounjaro is prescription-only and available through two main routes: NHS specialist weight management services (tier 3 or tier 4) and private online prescribing through GPhC-registered pharmacies. Access via the NHS involves referral from your GP to a specialist service, though waiting lists vary significantly by region. Private prescribing is faster — you complete an online clinical assessment with a UK-licensed prescriber, and if approved, your prescription is dispensed by a regulated pharmacy.
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 Cost and Private Access in the UK
The cost of Mounjaro on the private market in the UK typically ranges from £129 to £320 per month, depending on the dose and the pharmacy provider. The 10mg dose sits in the mid-to-higher price range. Prices vary because different providers have different procurement costs and pricing structures — it is worth checking current costs across regulated providers.
NHS access is free at the point of use but is subject to availability and regional variation. NICE has approved tirzepatide for NHS weight management services, but access depends on meeting eligibility criteria and being referred through your GP to a specialist tier 3 service. Many areas have significant waiting lists.
When considering private access, always use a GPhC-registered online pharmacy and ensure the prescriber is UK-licensed. Our GLP-1 weight loss calculator can help you estimate potential outcomes at different doses, which may help inform your discussion with a prescriber about whether a 10mg dose or another dose level is appropriate for you.
- 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 the Mounjaro KwikPen really a "click pen"?
No — despite its name, the KwikPen is not clicked multiple times. It is a pre-filled auto-injection device. You simply remove the pen from the fridge, prepare the injection site, and press and hold the button to deliver the entire dose automatically. The term "click" may come from older injection devices, but modern KwikPens do not work this way.
How do I know my Mounjaro KwikPen contains 10mg?
The dose is printed on the pen label and the outer packaging. Each pen is pre-filled with a specific dose: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, or 15mg. The pharmacist will dispense the correct dose for your prescription. Do not rely on guessing — always check the label before injecting.
Can I get Mounjaro through the NHS if I don't have a Type 2 diabetes diagnosis?
Yes. NHS eligibility is based on BMI and weight-related health conditions, not diabetes status. You must have a BMI of 30 or above, or 27–29.9 with a condition like high blood pressure, prediabetes, or sleep apnoea. Referral is through your GP to a specialist weight management service.
How much does a 10mg Mounjaro pen cost on the NHS?
NHS treatment is free at the point of use, but availability and waiting times vary significantly by region. Contact your local GP to ask about specialist weight management services in your area and expected waiting times.
How does Mounjaro compare to Wegovy in terms of access and cost?
Both are prescription-only and available privately in the UK at similar costs (£129–£320 per month depending on dose). Mounjaro is a dual GIP/GLP-1 agonist, while Wegovy is a GLP-1 agonist only — they have slightly different mechanisms. Both are available through NHS specialist services and private prescribing. Your prescriber will assess which is more suitable for you individually.
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.