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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Half Dose Mounjaro: UK Cost and Access Guide
Starting on a half dose of Mounjaro (tirzepatide) means beginning with the 2.5 mg starting dose, which is typically the first step in dose titration before progressing to maintenance doses like 5 mg or higher. If you're considering or already using Mounjaro through a UK prescription, understanding the cost structure and access routes — whether NHS or private — is essential for planning your weight management journey. This guide explains what you'll actually pay and how to access this medication 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.
Private Prescription Costs by Dose
Private Mounjaro costs in the UK vary significantly depending on your dose and which provider you choose. Starting doses (2.5 mg) typically cost between £129 and £200 per KwikPen, with each pen containing four weeks of injections. As you progress through dose titration to the 5 mg dose, expect costs to range from £150 to £250 per pen. Maintenance doses at 10 mg and above generally cost between £180 and £320 per month, depending on your prescriber and pharmacy. Several factors affect your final cost: the prescriber's consultation fee (usually £50–£120), the pharmacy's markup, and whether you're using an established online service with set pricing or a bespoke private GP clinic. Many providers offer package deals or subscription models that reduce per-dose costs if you commit to multiple months. Always ask about their full pricing upfront, including consultation fees and any additional charges.
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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 to Mounjaro
NHS access: Mounjaro is available through specialist tier 3 weight management services following NICE approval, but only if you meet strict eligibility criteria (BMI ≥30 or BMI ≥27.5 with weight-related conditions, depending on ethnicity). You'll need a GP referral and may face lengthy waiting lists — some regions have delays of 6–18 months. Once approved, there is no cost to you. Private access: You can obtain a UK prescription without NHS referral by completing an online clinical assessment with a licensed prescriber. This is faster (typically days to a week) and doesn't require a GP referral, making it the more accessible route for immediate treatment. Your GP can advise on NHS eligibility and timelines, whilst private options offer speed and convenience at out-of-pocket cost. Comparing Mounjaro vs Wegovy on cost is also worth considering — semaglutide may be slightly cheaper at lower doses with some providers.
- 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 half dose Mounjaro cheaper than the full maintenance dose?
Yes. Starting doses (2.5 mg) cost roughly £130–£200 per pen, while higher doses (10–15 mg) cost £180–£320. However, you'll need to progress through doses over several weeks during titration, so the total cost over your treatment is similar whether you start low or high. Your prescriber will guide your dose escalation.
Can I get Mounjaro on the NHS if I start at a half dose?
NHS access is through specialist tier 3 services after GP referral, regardless of starting dose. You must meet BMI eligibility thresholds and be assessed by a specialist team. Waiting lists vary by region; ask your GP about timelines and whether your local ICB is currently accepting referrals.
How does dose titration affect my overall treatment cost?
Dose titration means you start at 2.5 mg and increase gradually (usually 4 weeks per dose level). This spreads your costs across several months before reaching maintenance. Total spend depends on your final maintenance dose — some people stop at 5 mg, others progress to 10 mg or 15 mg based on response and side effects.
What's included in private Mounjaro prescription costs?
Private costs typically include the prescriber's consultation fee (£50–£120), the prescription itself, and the medication from a GPhC-registered pharmacy. Some providers bundle consultations and medication in one monthly fee. Always confirm whether your quoted price covers repeat prescriptions or if you'll pay per consultation.
Is Mounjaro more or less expensive than other GLP-1 injections on the NHS?
On the NHS, medication costs are covered if you're approved — you only pay your standard prescription fee (currently £9.90 in England). Private costs vary: Mounjaro KwikPens are typically comparable to Wegovy pricing per dose, though individual prescribers' fees vary significantly.
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.