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 Injection: Before and After — UK Costs and Access
If you're considering Mounjaro (tirzepatide) for weight management in the UK, understanding how to access it and what it costs is essential. Mounjaro is a prescription-only weekly injection, and access depends on whether you pursue an NHS route through specialist services or a private prescription. This guide explains both pathways, typical costs, and what happens before you start and during your treatment. Individual results vary significantly, and any decision should be made following a clinical assessment by a qualified healthcare professional.
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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 Cost Context in the UK
Private prescription costs for Mounjaro in the UK typically range from £129 to £320 per month, depending on your starting dose and the provider you choose. Most people begin on a 2.5 mg dose and gradually increase over several weeks in a process called dose titration — this means your initial costs may be lower than the maximum dose price. Private access does not require an NHS referral; instead, you complete an online clinical assessment with a UK-licensed prescriber who determines whether Mounjaro is suitable for you.
- Starting doses (2.5–5 mg): usually £129–£180 per month
- Mid-range doses (7.5–10 mg): typically £180–£240 per month
- Maximum dose (15 mg): usually £240–£320 per month
Costs may be higher if you choose express delivery or additional monitoring appointments. As a weekly weight loss injection, you'll need a fresh KwikPen every four weeks, so budget accordingly. Calculate your potential treatment costs using our free GLP-1 weight loss calculator, which shows dose progression and timescales.
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 Route vs Private Access: What to Expect
NHS access to Mounjaro for weight management is through specialist tier 3 weight management services, not your GP. You'll need a referral from your GP, but availability and waiting times vary significantly across UK regions. Some NHS integrated care boards (ICBs) have long waiting lists — sometimes months or years.
The online consultation process for private access is straightforward: you answer health questions, declare any medications, and confirm your height and weight. A prescriber will assess your BMI (using our free BMI calculator above to check yours first is helpful) and any weight-related health conditions. If approved, a prescription is issued to a GPhC-registered pharmacy, and your weekly weight loss injection is dispatched to your home. Track your progress with our free progress tracker once you start 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 long does the private online assessment for Mounjaro take?
Most online consultations take 10–15 minutes. You'll answer a health questionnaire, discuss your weight history and current medications, and confirm your eligibility. Results are typically available within 24 hours. If approved, your prescription is issued to a pharmacy for dispatch.
Is Mounjaro available on the NHS in all UK regions?
NICE has approved tirzepatide for NHS use, but access through NHS specialist services varies widely by region and ICB. Some areas have established weight management pathways; others have very long waiting lists. Contact your local integrated care board or ask your GP about specialist services in your area.
Can I switch from NHS Mounjaro to private, or vice versa?
Yes, but this should be managed carefully with your healthcare provider. If switching from NHS to private, ensure continuity by discussing the timing with your current prescriber. You cannot simply pause and restart without medical guidance — discuss any switch with a qualified healthcare professional first.
What does "dose titration" mean for Mounjaro costs?
Dose titration is the gradual increase in your Mounjaro dose every 4 weeks, starting at 2.5 mg up to a maximum of 15 mg. This means your first month's cost is lower than later months. Most people spend 4–5 months titrating before reaching their optimal maintenance dose.
Are there any hidden costs with private Mounjaro treatment?
Prescription costs are transparent, but some providers may charge for additional GP monitoring letters, faster delivery, or follow-up consultations. Always confirm the full cost upfront, including any optional extras, before starting treatment. Storage (refrigeration) costs are minimal — standard fridge storage is fine.
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.