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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How to Access 1.25mg Mounjaro in the UK
1.25mg is not a standard Mounjaro dose in the UK — the starting dose is 2.5mg, with escalation weeks built into the treatment schedule. However, understanding how Mounjaro (tirzepatide) is accessed and what it costs is essential if you're considering this prescription-only weight management injection. This guide explains your options through the NHS and private prescribing, what each route involves, and realistic costs based on current UK pricing. Whether you're starting Mounjaro or exploring whether it's right for you, we'll help you understand the full cost and access picture.
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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 Prescription Costs and Access Routes in the UK
Private online prescribing is currently the most accessible route to Mounjaro in the UK. Following an online clinical assessment with a UK-licensed prescriber, a private prescription can be issued and dispensed by a GPhC-registered pharmacy. Private costs for Mounjaro typically range from £129 to £320 per month, depending on the dose (starting doses are lower cost than maintenance doses like 10mg or 15mg). The starting dose, 2.5mg, is usually at the lower end of this price range. Each KwikPen contains four weekly injections, so you're purchasing a month's supply at a time. Private prescribing requires no NHS referral and can be quicker than NHS routes, though you pay upfront. Costs vary between providers based on their assessment fees and pharmacy partnerships, so comparison is worth doing. Some private providers offer subscription models or dose-stacking options that may reduce overall costs if you're planning longer-term treatment.
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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: Timeline and Eligibility
NHS access to Mounjaro is available but limited by regional availability and waiting lists. NICE approved tirzepatide for use within NHS weight management services, but prescription is only through tier 3 specialist services — not standard GP prescription. You'll need a referral from your GP to a specialist weight management service in your area. NHS waiting lists can range from several months to over a year depending on your region and service capacity. Eligibility is the same whether NHS or private: BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or obstructive sleep apnoea. If you're eligible and have access to NHS services, this route is free at the point of use. Check with your local integrated care board (ICB) to find out whether tirzepatide is available in your area and current waiting times.
- 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 1.25mg a real Mounjaro dose?
No. The starting Mounjaro dose in the UK is 2.5mg once weekly for the first four weeks, then it's escalated based on tolerability. There is no 1.25mg dose available. If you've seen this dose mentioned, it may be a misunderstanding of the titration schedule.
How much does Mounjaro cost on the NHS?
Mounjaro is free on the NHS if prescribed through a specialist tier 3 weight management service after assessment and referral from your GP. However, NHS availability varies significantly by region, and waiting lists can be lengthy.
What's included in the private cost of Mounjaro?
The price typically covers the prescription assessment fee (charged by the clinic), the prescription itself, and the medication dispensed by the pharmacy. Some providers include follow-up consultations; others charge separately. Always clarify what's included before committing.
How long does it take to get Mounjaro privately?
Private prescribing is usually faster than NHS routes. After completing an online assessment (typically 24–48 hours), a prescription can be issued and your first KwikPen dispatched within 3–5 working days. NHS routes can take months due to referral and waiting list processes.
Does private Mounjaro prescription cost the same as Wegovy?
Pricing is similar but can differ. Both are weight management injections costing approximately £150–£300 per month depending on dose. Compare specific providers for exact pricing, and remember that Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist, whereas Wegovy (semaglutide) is GLP-1 only — they're different medications.
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.