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
Mounjaro 2.5mg — UK Cost and Access Guide
Mounjaro 2.5mg is the standard starting dose of tirzepatide available in the UK, delivered via a KwikPen injection once weekly. This guide explains how to access it, what it costs, and the difference between NHS and private routes. The 2.5mg dose is used for the first four weeks of treatment before increasing to the next dose level as part of the standard dose titration schedule. Whether you're exploring NHS specialist services or private prescription options, understanding the cost and access pathways will help you make an informed decision about weight management treatment in the UK.
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.
Cost and Private Prescription Access in the UK
Private prescription costs for Mounjaro 2.5mg vary depending on the prescribing provider, but typically range from £129 to £180 per KwikPen (four-week supply) through private online services. Each pen contains four pre-filled doses of 2.5mg, so you'll need one pen per month at this starting dose level.
The total cost includes both the prescription consultation fee (usually £10–£35) and the medication itself. Some providers offer package pricing if you commit to multiple months upfront, which may reduce the per-dose cost. Private access does not require an NHS referral — you simply book an online consultation with a UK-licensed prescriber who will assess your eligibility based on your BMI, health history, and weight-related conditions.
Dispensing is handled by a GPhC-registered pharmacy, and your medication is delivered to your address. Private prescription access is typically faster than NHS routes, with treatment starting within 1–2 weeks if approved. This route is suitable for those who don't qualify for NHS services or who prefer not to wait for specialist appointment availability.
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 Access vs Private Prescription Routes
NHS route: Mounjaro is available through NHS specialist tier 3 weight management services in some areas, but access is restricted and varies significantly by region. You'll need a referral from your GP, and the 2.5mg starting dose will be managed by the specialist service. Waiting lists can be lengthy—sometimes months to over a year in some ICBs. Once approved, NHS provision is free, but availability depends on local commissioning decisions.
Private route: Much faster access. You complete an online health questionnaire, have a consultation with a prescriber (usually within 24–48 hours), and if approved, your KwikPen is dispatched to your home. You'll continue to pay for each dose throughout your treatment. Use our free GLP-1 weight loss calculator to explore projected outcomes at different dose levels, and the BMI calculator to confirm your current eligibility threshold.
- 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.
How long does it take to get Mounjaro 2.5mg on the NHS?
NHS access through specialist weight management services varies by region (ICB). Referral from your GP can take weeks, and then specialist appointment waiting lists can range from several months to over a year in some areas. Some regions have very limited access. Check your local ICB's commissioning policy or ask your GP about availability in your area.
Can I get Mounjaro 2.5mg privately without seeing my GP?
Yes. Private online prescription services allow you to access Mounjaro without an NHS referral. You'll complete an online health assessment and have a consultation with a UK-licensed prescriber. If approved, you pay privately and the medication is dispensed by a GPhC-registered pharmacy. No GP involvement required, though it's always wise to inform your GP about any medication you're taking.
What's included in the private prescription cost for Mounjaro 2.5mg?
Private costs typically include the consultation fee (£10–£35) plus the medication cost (£129–£180 per KwikPen). Each KwikPen contains four weekly doses, so at 2.5mg you'll use one pen per month. Some providers bundle consultations and ongoing prescriptions, which may offer better value over multiple months. Always confirm the total cost upfront.
Will my dose stay at 2.5mg or will it increase?
2.5mg is the starting dose only. The standard dose titration schedule increases every four weeks: 2.5mg (weeks 1–4), then 5mg, 7.5mg, 10mg, 12.5mg, and up to 15mg. Your prescriber will assess your tolerance and results at each step before increasing. Most people move through doses more quickly than they expect.
How does Mounjaro 2.5mg differ from Wegovy for cost and access?
Mounjaro is a dual GIP/GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Private costs are similar (both around £129–£180 per month at starting doses). Both require prescription and clinical assessment. Availability and pricing may vary slightly between providers. Compare both options with your prescriber to understand which suits your health profile and circumstances best.
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.