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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Mounjaro Doses in the UK: Cost, Access & How to Get Started
Mounjaro (tirzepatide) is available in the UK through both NHS specialist services and private prescribing routes, with costs varying significantly depending on your access method. Understanding the different doses, their prices, and how to access this GLP-1 receptor agonist injection can help you make an informed decision about whether this weight management option is right for you. This guide covers everything you need to know about getting Mounjaro in the UK, from initial dose through to maintenance, including what you'll pay and how long the process takes.
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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.
Mounjaro Doses and UK Private Prescription Costs
Mounjaro is prescribed in escalating doses, starting at 2.5 mg and increasing to a maximum of 15 mg weekly. Each KwikPen contains four weekly doses (a one-month supply). In the UK private market, costs typically range from £129 to £320 per month depending on the dose and provider, with higher doses commanding higher prices.
- 2.5 mg dose: approximately £129–£150/month (starter dose, weeks 1–4)
- 5 mg dose: approximately £150–£180/month (weeks 5–8, often the first maintenance dose)
- 10 mg dose: approximately £220–£270/month (escalation dose)
- 15 mg dose: approximately £280–£320/month (maximum dose)
Private prescriptions are issued by UK-licensed prescribers following an online clinical assessment. These costs are charged per KwikPen (one month's supply) and are paid directly to the pharmacy—there are no NHS prescriptions fees involved when accessing privately. Many people use our GLP-1 weight loss calculator to explore potential outcomes before committing to treatment.
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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 Access: What You Need to Know
In the UK, Mounjaro access splits into two distinct routes. NHS access is through tier 3 or 4 specialist weight management services, typically accessed via GP referral—but availability varies dramatically by region, and waiting lists can extend months or even years. Private access is through GPhC-registered online pharmacies following a clinical assessment by a UK prescriber, with no NHS waiting list but with out-of-pocket costs.
The online prescription process usually takes 24–48 hours from clinical assessment to dispensing. You'll need a valid UK postal address and an active debit or credit card. Once approved, your Mounjaro KwikPen is typically delivered within 2–3 working days. Your GP doesn't need to be involved in private prescribing, though it's advisable to inform them for your medical records. Use our BMI calculator to check your eligibility criteria before starting the consultation process.
- 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.
What's the difference between Mounjaro and Wegovy doses?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist with a maximum dose of 15 mg weekly, while Wegovy (semaglutide) is a GLP-1 agonist only with a maximum dose of 2.4 mg weekly. Approximate equivalence suggests Mounjaro 15 mg is similar in effect to Wegovy 2.4 mg, but direct comparison requires prescriber guidance. Dosing escalation differs significantly between the two.
Can I get Mounjaro for free on the NHS?
Yes, Mounjaro is available on the NHS through specialist tier 3/4 weight management services. However, access is regional and often involves significant waiting lists. Your GP can refer you to your local specialist weight management service, but availability and speed of access depend on your ICB (integrated care board) area. Private prescription remains faster but involves out-of-pocket costs.
How quickly does Mounjaro dosing escalate?
Mounjaro starts at 2.5 mg weekly and typically increases by 2.5 mg every four weeks until reaching an effective maintenance dose or the maximum 15 mg. Most people stabilise on 5 mg, 10 mg, or 15 mg depending on their individual response and tolerability. Your prescriber will assess whether to escalate based on side effects and weight loss progress.
Do I need a GP's approval to get a private Mounjaro prescription?
No. Private prescribers are independent healthcare professionals licensed to assess and prescribe. However, informing your GP is advisable for continuity of care and medical record-keeping. Your GP can provide context about your existing health conditions that may affect suitability, even if they're not directly involved in the private prescription process.
What's included in the monthly cost of Mounjaro?
The quoted monthly cost is for one KwikPen only (four weekly injections). It includes the medication, the pen device, and delivery. It does not include GP consultations (if private), storage supplies, or any additional support services. Some private providers offer optional coaching or monitoring packages at additional cost, but basic prescribing and dispensing are included in the headline price.
Ready to take control of your weight loss journey?
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