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 And Weight Loss In The UK — Cost And Access
Mounjaro (tirzepatide) is a prescription-only weekly weight loss injection licensed in the UK for adults with a BMI of 30 or above, or 27+ with weight-related health conditions. Access is available through both NHS specialist services and private online prescribing, though availability and costs differ significantly between routes. Understanding your options can help you make an informed decision about whether this medication is right for you. Our free GLP-1 weight loss calculator can help you estimate potential results at different doses.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Mounjaro Costs In The UK
Private Mounjaro prescriptions are typically available through UK-registered online pharmacies following a brief online clinical assessment with a licensed prescriber. Costs vary by dose and provider, but generally range from £129 to £320 per month depending on which dose strength you're prescribed.
- Starter doses (2.5–5 mg): Usually £129–£180 per month
- Maintenance doses (7.5–15 mg): Typically £220–£320 per month
- Each pen contains 4 once-weekly injections (one month's supply)
- Most providers offer subscription options with slight discounts
- Prescriptions are valid for 28 days from issue — you'll need regular repeat assessments
Private access avoids NHS waiting lists and requires no GP referral, making it faster for those who meet eligibility criteria. However, costs accumulate over time, especially as you progress to higher maintenance doses.
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: Which Route Is Right For You?
NHS route: Completely free once prescribed, but access is through tier 3 specialist weight management services. Eligibility requires GP referral and varies significantly by region. Many areas have waiting lists of 6–18 months. NICE approved Mounjaro for NHS use, but regional ICB (Integrated Care Board) funding decisions mean availability is inconsistent across the UK.
Private route: No GP referral needed and prescriptions are issued within days following online assessment. You pay full cost per month, but you control when treatment starts. The online consultation process is straightforward—you'll answer health questions and a UK-licensed prescriber decides if Mounjaro is suitable for you. Use our BMI calculator to check your eligibility before applying.
- 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 Mounjaro cost privately per month in the UK?
Private Mounjaro costs typically range from £129–£320 per month depending on your dose. Starter doses (2.5–5 mg) are usually £129–£180, while maintenance doses (7.5–15 mg) cost £220–£320. Each pen contains 4 weekly injections. Costs vary slightly between providers, and some offer subscription discounts.
Can I get Mounjaro free on the NHS in the UK?
Yes, Mounjaro is available free on the NHS through tier 3 specialist weight management services. However, you need a GP referral and regional availability varies. Many areas have significant waiting lists (6–18 months). NICE approved tirzepatide for NHS use, but funding decisions depend on your local ICB.
How do I get a private Mounjaro prescription online?
Complete a brief online health questionnaire with a UK-registered online pharmacy. A licensed prescriber reviews your answers and medical history. If eligible, you'll receive a prescription within 24–48 hours, which is then dispensed by the pharmacy. No GP referral is needed. The whole process typically takes 2–3 days.
What happens if I miss a Mounjaro injection or need to pause treatment?
If you miss a dose within 4 days of your scheduled injection date, take it as soon as you remember. If more than 4 days have passed, skip that dose and continue on your normal schedule—never double dose. If you need to pause treatment, inform your prescriber. Restarting typically requires reassessment.
Is Mounjaro more expensive than Wegovy for weight loss in the UK?
Costs are broadly similar for equivalent doses. Mounjaro (tirzepatide) ranges £129–£320/month privately, while Wegovy (semaglutide) typically costs £130–£300/month. Both require repeat prescriptions and ongoing clinical assessment. Your prescriber can advise which weekly weight loss injection suits your health profile and budget best.
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.