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 12.5 mg Cost in the UK?
Mounjaro (tirzepatide) at 12.5 mg is the second-highest maintenance dose available in the UK. The cost of accessing this dose varies significantly depending on whether you pursue NHS or private prescription routes. If you're considering Mounjaro for weight management, understanding the true cost and access pathways is essential before starting treatment. This guide explains UK pricing, eligibility, and how to find the most affordable option for your circumstances.
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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.
Private Prescription Costs for Mounjaro 12.5 mg in the UK
When accessing Mounjaro privately through UK-licensed online prescribers, the cost typically ranges from £199 to £299 per month at the 12.5 mg dose, depending on the provider and whether you're purchasing a single pen or a starter pack. Each KwikPen contains four weekly doses. At the 12.5 mg dose, you're paying for an established maintenance injection after weeks of dose titration — starting from 2.5 mg and gradually escalating every four weeks. Private costs are generally higher than lower doses because 12.5 mg represents a higher concentration and quantity of active tirzepatide. To access private Mounjaro, you'll need a consultation with a UK-licensed prescriber, who will assess your eligibility based on BMI, health conditions, and medical history. Once prescribed, the medication is dispensed by a GPhC-registered pharmacy. Use our free GLP-1 weight loss calculator to estimate potential outcomes at this dose based on clinical trial data, which may help justify the investment.
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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: Which Route Is Cheaper?
NHS route: If eligible and referred to a tier 3 specialist weight management service, Mounjaro may be provided free through the NHS — but availability varies dramatically by region, waiting lists can exceed 18 months, and only certain ICBs (integrated care boards) currently fund tirzepatide. Many adults find the NHS route inaccessible due to these barriers.
Private route: More expensive upfront (£199–£299/month at 12.5 mg), but immediate access without waiting lists. Some private providers offer package discounts for three-month or annual commitments, potentially reducing per-month cost. You can also use our BMI calculator to confirm your eligibility before consulting, and our progress tracker to monitor results once you've started treatment. The choice depends on your budget, timeline, and access to NHS services in your area.
- 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 Mounjaro 12.5 mg expensive compared to other weight loss injections?
Mounjaro 12.5 mg costs roughly similar to Wegovy (semaglutide) 2.4 mg in the UK private market — both typically £200–£300/month. Costs reflect the dose strength and weekly injection format. NHS access, where available, is free but involves long waits and eligibility criteria. Your GP can advise on NHS availability in your area.
Can I get Mounjaro 12.5 mg cheaper by buying online from abroad?
Mounjaro imported from abroad carries significant risks: counterfeit products, lack of UK medical oversight, potential customs issues, and no support if problems arise. UK-licensed private prescribers and GPhC pharmacies offer safety, proper clinical assessment, and accountability. Always use legitimate UK prescribing routes.
What does a Mounjaro 12.5 mg pen cost, and how long does it last?
One Mounjaro KwikPen at 12.5 mg costs approximately £199–£299 from private UK providers. Each pen contains four weekly injections, so one pen lasts exactly four weeks. At this dose, you'll need 13 pens per year if continuing long-term treatment.
Do I need a prescription to buy Mounjaro 12.5 mg in the UK?
Yes — Mounjaro is prescription-only in the UK. You cannot buy it without a valid prescription from a UK-licensed prescriber (either NHS or private). An online consultation with a private prescriber takes 10–20 minutes and includes eligibility assessment before a prescription is issued.
Does private health insurance cover Mounjaro 12.5 mg costs in the UK?
Most standard private health insurance policies do not cover weight management medications. Some specialist weight loss insurance products exist, but coverage is limited and often requires prior NHS referral. Check your policy details or contact your insurer directly for clarity on medication cover.
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.