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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Mounjaro Pen 5mg: UK Cost and Access Guide
Mounjaro 5mg is the first maintenance dose of tirzepatide, a prescription-only weight management injection available in the UK through NHS specialist services or private online prescribing. The cost, availability, and access route depend significantly on whether you pursue NHS or private treatment. This guide explains both pathways, what the 5mg dose is used for, and how to get started 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 Cost in the UK
Private prescription cost: A Mounjaro KwikPen containing four 5mg doses (one month's supply) typically costs between £150–£200 per month through private UK-registered online pharmacies, depending on the provider and any ongoing package discounts. Some providers offer reduced pricing for repeat prescriptions or annual packages. Prices are transparent and shown before purchase — there are no hidden charges.
- Cost per injection: Approximately £37.50–£50 per weekly 5mg injection when bought individually
- Annual private cost: Roughly £1,800–£2,400 per year if paying monthly, though this varies by provider and dose increases
NHS cost: Free through the NHS if prescribed by a specialist tier 3 weight management service, but NHS access is limited by regional availability and waiting lists, which can extend many months in some areas. Eligibility assessment and prescription are handled entirely by the NHS specialist team at no cost to you.
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 Routes
NHS route: Ask your GP for a referral to a specialist tier 3 weight management service. NICE has approved tirzepatide (Mounjaro) for use within NHS services for eligible adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions. NHS prescribing is free but subject to regional ICB (Integrated Care Board) funding decisions — some areas have limited availability or long waiting lists.
Private route: Complete an online consultation with a UK-licensed prescriber through a GPhC-registered pharmacy. If approved, a prescription is issued and dispensed. This typically takes 24–48 hours and requires no GP referral. Private prescribing follows the same clinical eligibility criteria but access is immediate. Use our free GLP-1 weight loss calculator to estimate potential outcomes and discuss results with your prescriber.
What to expect in an online consultation: You'll complete a detailed health questionnaire covering your medical history, current medications, weight, height, and why you're seeking treatment. A prescriber reviews this and may ask follow-up questions via phone or secure message. If approved, your prescription is sent to a pharmacy, and your first KwikPen is dispatched, usually with starter guidance. Your prescriber typically reviews your progress after 4 weeks and may recommend a dose increase. You'll need to repeat consultations every 3–6 months depending on the provider to continue prescriptions.
- 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 is the Mounjaro 5mg dose used for?
The 5mg dose is the first maintenance dose after the starting 2.5mg dose. Most people progress to 5mg in weeks 5–8 and remain on this dose if it's effective, or continue increasing to higher doses (7.5mg, 10mg, 15mg) depending on individual response and tolerability.
Is Mounjaro cheaper than Wegovy in the UK?
Mounjaro and Wegovy have similar private prescription costs (typically £150–£200 per month in the UK). Both are available through private online prescribing at roughly equivalent prices. Costs differ by provider and any promotional packages offered. NHS access for both is free but subject to regional availability.
Can I get Mounjaro on the NHS at 5mg?
Yes, if referred to and approved by an NHS tier 3 weight management service. However, NHS access varies significantly by region. Many areas have waiting lists of 6–12+ months. Your GP can advise on local availability and waiting times in your area.
How long does it take to access Mounjaro privately?
Private access is typically much faster than NHS. After completing an online consultation, most people receive their first KwikPen within 2–3 working days if approved. NHS routes can involve waiting months from GP referral to specialist appointment.
Do I need a GP letter to get Mounjaro privately?
No, a GP letter is not required for private online prescribing. However, your prescriber will ask detailed health questions to assess suitability. Some private providers recommend informing your GP for continuity of care, though this is optional. Check your BMI using our free BMI calculator to confirm your eligibility before starting the consultation process.
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.