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 2.5mg Cost in the UK?
Mounjaro 2.5mg is the standard starting dose for weight management in the UK, but cost depends entirely on whether you access it through the NHS or privately. NHS access is free at point of use but involves waiting times and specialist referral, while private prescriptions typically cost between £129 and £180 for a single 2.5mg KwikPen (four weekly doses). Understanding your options helps you find the most affordable route for your situation. Our free GLP-1 weight loss calculator can help you explore potential outcomes at different doses, while your GP or a licensed prescriber can assess your personal eligibility.
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 Prescription Costs for Mounjaro 2.5mg in the UK
Private prescriptions for Mounjaro 2.5mg typically cost between £129 and £180 per KwikPen, depending on the provider. A single pen contains four weekly doses, so the cost breaks down to approximately £32–£45 per week. This is the starting dose, so your first month will cost a single pen. Most private prescribers follow a dose titration schedule, increasing every 4 weeks through 5mg, 7.5mg, 10mg, 12.5mg, and finally 15mg maximum. Here's what affects the final price:
- Provider markup — varies between licensed online pharmacies
- Prescription fee — most private consultations cost £20–£50
- Frequency of dose increases — you'll need multiple pens over several months
- Bulk ordering discounts — some providers offer lower rates for ordering multiple pens
- Delivery fees — usually £3.99–£8.99 per order
Unlike semaglutide (Wegovy), tirzepatide (Mounjaro) may offer slightly different pricing structures across providers. Always compare total cost, not just per-pen price, when assessing affordability.
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: What's the Real Cost Difference?
NHS access to Mounjaro 2.5mg is free, but availability is extremely limited. You must be referred to a tier 3 specialist weight management service by your GP, and even then, waiting lists can exceed 12–24 months depending on your ICB area. Many regions have suspended new referrals due to demand. Private access bypasses NHS waiting times — you can start within 1–2 weeks of online consultation. If you're eligible for NHS specialist services, accessing Mounjaro through that route costs nothing. However, the alternative is either waiting months or paying privately. Using our free BMI calculator above confirms whether you meet the starting thresholds (BMI ≥30 or BMI 27–29 with weight-related health conditions). A licensed prescriber will assess your suitability during an online consultation before issuing a prescription to a GPhC-registered pharmacy.
- 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.
Is Mounjaro 2.5mg cheaper than Wegovy in the UK?
Pricing is similar across most private providers — typically £129–£180 per pen regardless of medication. However, semaglutide (Wegovy) starts at a lower dose (0.25mg) while tirzepatide (Mounjaro) starts at 2.5mg. Mounjaro's dual GIP/GLP-1 mechanism may produce different results, but cost alone doesn't differ significantly between the two.
Can I get Mounjaro 2.5mg on the NHS for free?
Yes, through NHS tier 3 specialist weight management services — but you must be referred by your GP and meet strict criteria (BMI ≥30 or BMI 27–29 with comorbidities). NHS access is free, but waiting lists are very long. Many areas currently have suspended new referrals entirely due to extremely high demand.
Do I need a prescription to buy Mounjaro 2.5mg?
Yes, Mounjaro is prescription-only in the UK. You cannot buy it without a valid prescription from a UK-licensed prescriber. Private online prescribers can issue prescriptions following an online clinical assessment if you meet eligibility criteria. The prescription is then dispensed by a GPhC-registered pharmacy.
What happens after the 2.5mg starting dose — do costs increase?
Yes. After 4 weeks on 2.5mg, most prescribers increase to 5mg, then follow a titration schedule. Each dose increase requires a new pen, so monthly costs rise gradually. A 15mg maintenance dose would cost roughly double the starting price. Your prescriber will discuss the full cost trajectory during your initial consultation.
Are there any discounts for buying Mounjaro 2.5mg long-term?
Some private providers offer loyalty discounts or reduced rates if you commit to ongoing prescriptions. Bulk ordering (e.g. purchasing 3 months at once) may offer modest savings. Always ask during your online consultation whether bulk or repeat-prescription discounts are available.
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.