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
When Will Mounjaro Be Cheaper in the UK?
Mounjaro (tirzepatide) remains expensive in the UK, but costs are likely to fall significantly once generic versions become available after the patent expires. Currently, you can access Mounjaro through the NHS via specialist tier 3 weight management services, or privately through online prescribing at costs ranging from £150–£300 per month depending on dose. Understanding the timeline for cheaper options can help you plan your weight management strategy. Use our free BMI calculator to check whether you may be eligible for treatment, and our GLP-1 weight loss calculator to explore potential outcomes.
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.
NHS Access vs Private Cost — What's Available Now?
Currently in the UK, Mounjaro is available through two routes: NHS specialist services (free on prescription if eligible) and private online prescribing (£150–£320 monthly). NHS access is through tier 3 or 4 weight management services — you'll need a GP referral and typically face waiting lists of several months to over a year in many regions. The Mounjaro KwikPen contains four weekly doses and requires careful dose titration, starting at 2.5 mg and increasing over weeks. Private costs vary by dose and provider — higher doses (10 mg, 15 mg) cost more. Unlike some medications, there's currently no official "cheap" Mounjaro option in the UK; all current supply comes from the manufacturer at premium pricing. Generic tirzepatide may eventually reduce these costs, but timelines remain uncertain.
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.
When Might Generic Tirzepatide Lower Prices?
Eli Lilly's patents on tirzepatide extend into the 2030s in most markets, meaning generic versions are unlikely before 2030–2035. Once patents expire, generic manufacturers can produce tirzepatide at lower cost — potentially reducing prices by 70–90%, similar to other generic injectable medications. However, UK pricing for generics depends on NHS negotiation and pharmacy supply chains. In the meantime, Mounjaro remains the only licensed tirzepatide option available. If cost is a barrier, discuss NHS referral with your GP — specialist services are free if you qualify. Alternatively, compare Mounjaro vs Wegovy pricing; Wegovy (semaglutide) is also available privately and may have different cost structures depending on dose and provider, though both are prescription-only and require clinical assessment.
- 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.
Will Mounjaro ever be available on the NHS for everyone?
Mounjaro is available on the NHS through specialist tier 3 weight management services for eligible adults. Eligibility requires a BMI of 30 or above, or 27 or above with weight-related health conditions. Access varies by region — some areas have shorter waiting lists than others. Ask your GP for a referral if you think you qualify.
How much does Mounjaro cost privately in the UK right now?
Private Mounjaro costs approximately £150–£320 per month depending on dose (higher doses cost more). This is through private online prescribing following a clinical assessment. Costs vary slightly between providers. Always confirm the exact price for your dose before starting.
Why is Mounjaro so expensive compared to other weight loss injections?
Mounjaro is expensive because it's a new, patented medication manufactured solely by Eli Lilly. The dual GIP/GLP-1 mechanism is relatively novel. Once generic tirzepatide becomes available after patent expiry (likely 2030s), prices should drop significantly — potentially by 70–90%.
Is Mounjaro cheaper than Wegovy in the UK?
Pricing varies between Mounjaro and Wegovy depending on dose and provider. Both are prescription-only and available privately at similar cost ranges (£130–£320/month). Your GP or prescriber can advise which option may be more cost-effective for your specific dose and circumstances.
What should I do if I can't afford private Mounjaro right now?
Discuss NHS referral with your GP — specialist tier 3 weight management services are free if you're eligible. Waiting lists exist in many areas, but it's worth asking about timescales. Alternatively, explore other evidence-based weight loss approaches through your GP, such as structured diet programmes or other NHS-supported interventions.
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.