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 Much Does Mounjaro 5mg Cost in the UK?
The Mounjaro 5mg KwikPen is the first maintenance dose escalation step in tirzepatide treatment, typically used from week 5 onwards. If you're considering this prescription-only weight management injection in the UK, it's important to understand both NHS and private access routes, as costs and availability vary significantly. This guide covers pricing, eligibility, and how to access Mounjaro legally and safely through a licensed prescriber in the UK.
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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.
Mounjaro 5mg Pen Cost in the UK
Private prescription costs: A Mounjaro 5mg pen (4 weeks' supply) typically costs between £150–£200 through private online prescribing services in the UK. Each KwikPen contains 4 individual doses. The total cost of treatment depends on how many weeks you take the medication and whether you continue escalating to higher doses (7.5mg, 10mg, 12.5mg, 15mg).
- Starter dose (2.5mg): approximately £129–£160
- First maintenance (5mg): approximately £150–£190
- Higher doses (10mg–15mg): approximately £180–£250 per pen
NHS access: If prescribed through the NHS, Mounjaro is free at the point of care (standard prescription charge applies in England — £9.90 per item, or free if eligible). However, NHS availability is limited to specialist tier 3/4 weight management services and varies significantly by region. Waiting lists can be lengthy — in many areas, several months to over a year.
Use our free GLP-1 weight loss calculator to estimate potential results at the 5mg dose, and try our BMI calculator to check if you meet initial eligibility criteria (BMI 30 or above, or 27+ with weight-related health conditions).
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: Which Route Is Right for You?
NHS route: Request a referral from your GP to a local specialist weight management service (tier 3). Mounjaro has been approved by NICE for NHS use, but access depends on your integrated care board (ICB) and current service capacity. Some regions have suspended new referrals due to demand. Once assessed and approved, the medication is free (or £9.90 prescription charge). However, you'll need to wait for an appointment and follow NHS dose titration protocols.
Private route: Book an online consultation with a UK-licensed prescriber through a GPhC-registered pharmacy. The assessment takes 10–30 minutes. If approved, your prescription is sent to a pharmacy and dispatched within 1–2 working days. You pay the full cost but access treatment immediately without waiting lists. Private prescribers follow the same clinical eligibility criteria as the NHS.
Online consultation checklist: Have your height, weight, blood pressure (if possible), and current medications ready. Be honest about your health history — prescribers assess contraindications seriously. If you're taking oral contraceptives, inform the prescriber (tirzepatide may reduce absorption).
- 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 5mg pen available on the NHS?
Yes, NICE has approved tirzepatide (Mounjaro) for NHS use within specialist weight management services (tier 3/4). However, availability varies by region and waiting times can be several months to over a year. Your GP can refer you to your local service, but not all areas have capacity. Private access typically offers faster treatment initiation.
What does a private Mounjaro 5mg prescription cost compared to other doses?
The 5mg pen typically costs £150–£200 through private prescribers, making it one of the mid-range doses. The 2.5mg starter is cheaper (£129–£160), whilst higher doses (10mg–15mg) range from £180–£250. Total treatment cost depends on your final dose and duration of treatment.
How long does a Mounjaro 5mg pen last?
Each KwikPen contains exactly 4 doses (one per week), so a single pen lasts 4 weeks. You'll need a new pen each month whilst on this dose. If you progress to higher doses later, you'll continue ordering monthly pens until you reach your target maintenance dose or discontinue treatment.
Can I get Mounjaro 5mg without a prescription?
No. Mounjaro (tirzepatide) is a prescription-only medicine in the UK and is not available over the counter or without a clinical assessment. You must obtain a valid prescription from a UK-licensed prescriber — either through your GP and NHS services, or via a private online consultation with a GPhC-registered pharmacy.
What eligibility criteria must I meet to access Mounjaro 5mg privately?
Standard criteria include BMI 30 or above, or BMI 27–29.9 with at least one weight-related health condition (type 2 diabetes, high blood pressure, sleep apnoea, cardiovascular disease). Lower thresholds apply for South Asian, Chinese, Black African, and Caribbean heritage. A licensed prescriber will assess your individual suitability during consultation. Use our BMI calculator to check your starting position.
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.