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
How to Get Mounjaro 15mg in the UK
Mounjaro 15mg is the maximum licensed dose of tirzepatide available in the UK for weight management. Access is possible through both NHS specialist services and private online prescribing routes, though costs, timelines, and eligibility criteria differ significantly. Understanding your options helps you make an informed decision about accessing this prescription-only 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 Access and Costs in the UK
Private prescription access for Mounjaro in the UK is available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. Private costs typically range from £180 to £320 per month depending on the dose and provider. At the 15mg maintenance dose, you can expect costs toward the higher end of this range. Each KwikPen contains four weekly injections, so a single pen lasts approximately one month. Private access does not require an NHS referral and avoids waiting lists, making it faster than the NHS route. However, costs are entirely out-of-pocket. Prescribers will assess whether tirzepatide is clinically appropriate based on your BMI, health conditions, and medical history. Use our free GLP-1 weight loss calculator to estimate potential outcomes at the 15mg dose before pursuing private access.
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 Access vs Private Routes
NHS access to Mounjaro is through specialist tier 3 weight management services following a GP referral. NICE (National Institute for Health and Care Excellence) has approved tirzepatide for use within NHS specialist services, but availability varies significantly by region. Many areas have extended waiting lists—sometimes 6–12 months or longer. NHS prescribing is free, making it far more affordable than private costs. However, you must meet strict eligibility criteria and be referred by your GP. Private access is faster but costs £2,160–£3,840 annually at 15mg. Some patients choose private access for immediate availability while remaining on NHS waiting lists as a backup. Always discuss both options with your GP to understand your regional NHS availability and whether private access is feasible for you. Our BMI calculator can help confirm your eligibility threshold before speaking to your GP or prescriber.
- 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 typical monthly cost for private Mounjaro 15mg in the UK?
Private costs typically range from £250–£320 per month for the 15mg dose, depending on the provider. This covers the KwikPen device and clinical assessment fees. Some providers offer discounts for upfront payment or multiple pens, reducing the per-month cost slightly.
How long does it take to get Mounjaro on the NHS?
NHS access timelines vary by region (integrated care board). Many areas have waiting lists of 6–12 months or longer due to high demand. Your GP can check your local NHS tier 3 service availability and estimated waiting time when you request a referral.
Do I need a GP referral for private Mounjaro?
No. Private access through GPhC-registered online pharmacies does not require an NHS referral. You complete an online consultation with a UK-licensed prescriber, who assesses your eligibility and issues a prescription directly if appropriate.
Is Mounjaro 15mg the dose I'll start on?
No. Mounjaro uses a gradual dose escalation schedule. You start at 2.5mg and increase every 4 weeks until reaching your therapeutic dose. Most people reach 10mg or 15mg over 16–20 weeks. Your prescriber determines your optimal dose based on response and tolerability.
What happens if I can't afford private Mounjaro?
Discuss alternatives with your GP, including NHS referral to specialist services, other GLP-1 medications like Wegovy or Saxenda, or lower-cost tier 1 and tier 2 NHS lifestyle interventions. Your GP can explore options suitable for your circumstances and budget.
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.