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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2.5 Ml Mounjaro Cost and Access in the UK
The 2.5 ml Mounjaro KwikPen is the starting dose of tirzepatide, a prescription weight management injection licensed in the UK. Understanding your options for accessing it — whether through NHS specialist services or private prescription — helps you make an informed decision about cost and availability. This guide explains both routes and what to expect when seeking this medication.
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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 Prescription Cost and Availability
In the UK, private Mounjaro prescriptions are typically available through online clinics and GPhC-registered pharmacies. The cost of a 2.5 ml Mounjaro KwikPen (one starter pen containing four weekly doses) generally ranges from £129 to £180, though prices vary by provider and your location. Each pen lasts four weeks at the starting dose.
- Costs increase as you progress to higher doses during titration (5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg)
- Many providers offer subscription models or discounted multi-month packages
- Private prescriptions require an online clinical consultation, usually costing £15–£50 separately
- Payment is typically upfront before the medication is dispensed
Prices and availability vary, so comparing providers is worthwhile. Unlike Wegovy or other GLP-1 medications, tirzepatide's dual GIP and GLP-1 mechanism means some providers may have different stock or pricing structures.
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 access to Mounjaro is through specialist tier 3 weight management services, usually requiring a GP referral. However, availability is severely limited in many regions, with waiting lists often extending 12–24 months. Private access bypasses NHS waiting lists entirely — you can start treatment within days of a successful online clinical assessment.
The private route is more expensive upfront but faster. An online prescriber will assess your eligibility, BMI, and health history before issuing a prescription. You'll need to complete a health questionnaire honestly, and your prescriber may request additional health information. Once approved, your prescription is sent to a GPhC-registered pharmacy for dispatch. Most first orders arrive within 2–5 working days.
Use our free GLP-1 weight loss calculator to estimate potential weight loss projections at the starting dose, and our BMI calculator to confirm your eligibility before consulting a prescriber. Tracking your progress with our free progress tracker can help you monitor outcomes once you begin treatment.
- 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 a 2.5 ml Mounjaro pen cost privately in the UK?
A single 2.5 ml KwikPen (four weekly doses) typically costs between £129 and £180 from private UK providers. The clinical consultation fee is usually separate, ranging from £15 to £50. Prices may vary by provider, and some offer discounts for purchasing multiple pens at once.
Can I get Mounjaro on the NHS if I want to start at 2.5 ml?
Mounjaro is available on the NHS through specialist weight management services (tier 3), but access is extremely limited with significant waiting lists in most regions. Your GP would need to refer you, and NICE has approved tirzepatide for use within these services, but regional ICB funding varies considerably.
What is included in the cost of a 2.5 ml Mounjaro KwikPen?
A KwikPen contains four pre-filled weekly injections at the 2.5 ml (2.5 mg) starting dose. The cost covers the medication only — the pen device itself is reusable, and you'll receive a new pen weekly for four weeks, then progress to the next dose if prescribed.
How do online Mounjaro prescriptions work in the UK?
You complete a health questionnaire with a UK-licensed prescriber. If approved, they issue a prescription sent to a GPhC-registered pharmacy. The pharmacy dispenses your KwikPen and arranges delivery, usually within 2–5 working days. You'll receive ongoing support and dose escalation guidance from the prescriber.
Is Mounjaro cheaper than Wegovy in the UK?
Pricing is similar between tirzepatide (Mounjaro) and semaglutide (Wegovy), typically £129–£200 per month privately depending on dose and provider. Mounjaro's dual GIP and GLP-1 mechanism may appeal to some patients, but individual costs and prescriber availability vary, so comparing providers is recommended.
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.