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 Much Does Mounjaro Cost Per Month in the UK?
Mounjaro (tirzepatide) costs vary significantly in the UK depending on whether you access it through the NHS or via private prescription. Privately, monthly costs typically range from £129 to £320 per month depending on your dose, with the starting 2.5 mg dose at the lower end and higher doses costing more. NHS access is free at point of care but requires referral to specialist weight management services, which varies by region and availability. Understanding both routes and what affects pricing can help you make an informed decision about accessing this weight loss medication.
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 prescription costs for Mounjaro typically range from £129 to £320 per month, depending on the dose you are prescribed. Starting doses (2.5 mg) are usually at the lower end of this range, while higher maintenance doses (10 mg to 15 mg) cost more. Each KwikPen contains 4 weekly doses, so a monthly cost represents one pen. Prices vary between online pharmacy providers, so shopping around is worthwhile.
- 2.5 mg dose: Approximately £129–£150/month
- 5–7.5 mg dose: Approximately £170–£200/month
- 10–15 mg dose: Approximately £250–£320/month
Private prescription costs include the clinical assessment fee (typically £20–£50) plus the medication cost. These are private costs paid directly by you; prescription charges do not apply as they would with NHS prescriptions in England.
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 vs Private Access: Cost & Availability
NHS access to Mounjaro is free at the point of care once prescribed, but availability is extremely limited. NICE (National Institute for Health and Care Excellence) has approved tirzepatide for NHS use within specialist tier 3 weight management services, but not all regions offer it yet. Waiting lists for NHS specialist services can be many months to years long depending on your ICB (Integrated Care Board) area. Private online prescription routes offer faster access without NHS referral, though you pay the full medication cost. An online clinical assessment with a UK-licensed prescriber takes 15–20 minutes and costs £20–£50, after which a prescription is issued if deemed clinically appropriate.
- 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.
Why does Mounjaro cost more at higher doses?
Higher doses of tirzepatide (the active ingredient in Mounjaro) require larger amounts of medication per dose. Starting doses are lower because they are used for the first 4 weeks during the titration phase. As you progress through dose escalation, each higher dose contains more tirzepatide, which increases manufacturing and supply costs passed to pharmacies and patients.
Can I get Mounjaro on the NHS for free?
Yes, Mounjaro is free via the NHS once prescribed, but access is limited to specialist tier 3 weight management services. Not all regions offer it yet, and waiting lists are often very long (months to years in many areas). Your GP can refer you to your local specialist service, but availability depends on your ICB and current commissioning decisions.
What's included in the private prescription cost?
Private costs cover the clinical assessment consultation (£20–£50), the prescription itself, and the medication (KwikPen). Some providers bundle these; others charge separately. The medication cost is the largest component. You should ask your provider for a full breakdown before starting treatment.
How long does one KwikPen last?
One KwikPen contains 4 weekly doses, so it lasts approximately 4 weeks (one month). If you are taking Mounjaro 2.5 mg weekly, one pen covers 4 weeks. When you increase doses, you still receive one pen per month, though the cost per dose within that pen will be higher at higher dose levels.
Are private Mounjaro prices fixed or do they vary between providers?
Prices vary between different online pharmacy providers. Some may offer the same dose at different costs, so it is worth comparing. Prices also vary by dose level. Always ask about the total cost upfront, including any consultation or assessment fees, to understand the full monthly expense.
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.