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 2.5 Mg Weight Loss: Cost and Access in the UK
Mounjaro 2.5 mg is the starting dose of tirzepatide, a weekly weight loss injection available in the UK through both NHS specialist services and private prescription routes. Understanding how to access this medication and what it costs depends on which pathway you choose. This guide explains the UK prescription process, typical costs, and how the starting dose fits into your treatment journey.
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.
Private Access and Cost: What to Expect
In the UK, the 2.5 mg starting dose of Mounjaro is typically accessed through private online prescription services following a clinical assessment. Private costs vary by provider and dose, but generally range from £120–£180 per month for the starting dose, depending on which GPhC-registered pharmacy dispenses your prescription.
- Each Mounjaro KwikPen contains 4 weekly doses (4 weeks' supply)
- Your prescriber assesses eligibility based on BMI and health conditions
- Prescription issued by a UK-licensed prescriber if clinically appropriate
- Dispensed through GPhC-registered pharmacies within 1–3 working days
- You'll typically remain on the 2.5 mg dose for 4 weeks before escalating
This weekly weight loss injection requires a valid UK prescription — you cannot purchase it over the counter. The starting dose allows your body to adjust to the medication before moving to higher doses for greater appetite suppression.
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 Routes: How to Access Mounjaro
NHS access: Mounjaro is approved by NICE for NHS specialist weight management services, but availability varies significantly by region and waiting lists can be lengthy (often months to years). You'll need a GP referral to a tier 3 or tier 4 specialist service.
Private access: Faster route — complete an online health assessment with a UK-licensed prescriber, receive a prescription if eligible, and have medication dispensed by a GPhC pharmacy. Online consultations typically cost £20–£50, then medication costs apply separately. Use our GLP-1 weight loss calculator to estimate potential outcomes across all dose stages, including the 2.5 mg starting point.
Both routes require clinical assessment — your prescriber will confirm you meet eligibility criteria (BMI ≥30, or ≥27 with weight-related health conditions) before issuing a prescription.
- 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 much does the 2.5 mg starting dose of Mounjaro cost in the UK?
Private costs typically range from £120–£180 per month for the starting dose, depending on the pharmacy. Each KwikPen (4-week supply) is included in this price. NHS costs are covered by the NHS if prescribed through specialist services, though waiting lists vary by region. Your GP can refer you to local tier 3 weight management services.
Why is 2.5 mg the starting dose and how long do you stay on it?
The 2.5 mg dose allows your body to tolerate the medication and adjust to side effects like nausea. You typically remain on this dose for 4 weeks before your prescriber increases it. This gradual escalation (called dose titration) is safer and helps minimise gastrointestinal side effects.
How quickly can I get a private Mounjaro prescription in the UK?
Private online consultations are usually completed within 24–48 hours. If approved, your prescription is sent to a GPhC-registered pharmacy, with medication typically dispatched within 1–3 working days. NHS access is slower due to referral pathways and waiting lists, which can extend to many months in some areas.
Can I buy Mounjaro without a prescription in the UK?
No — Mounjaro is a prescription-only medicine. You cannot purchase it over the counter or without a valid prescription from a UK-licensed prescriber. Any website claiming to sell Mounjaro without a prescription is operating illegally and should be reported to the MHRA.
What's the difference between Mounjaro and a weekly weight loss injection like Wegovy?
Mounjaro is a dual GIP and GLP-1 receptor agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials show Mounjaro may produce slightly higher average weight loss (15–21% vs around 15% for Wegovy), though individual results vary significantly. Both require prescriptions and cost similarly in private access routes.
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.