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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Cheapest 2.5mg Mounjaro — UK Pricing & How to Access It
The 2.5mg dose is Mounjaro's starting dose and is typically the most affordable entry point if you're accessing the medication privately in the UK. However, "cheapest" depends on whether you're eligible for NHS access or pursuing private prescription. This guide explains UK pricing, where to find it, eligibility criteria, and why this dose is used as the initial step in tirzepatide treatment.
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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.
Understanding Mounjaro 2.5mg and Pricing in the UK
2.5mg is the initial dose — it's designed for the first 4 weeks of treatment, after which prescribers increase the dose weekly. This starting dose allows your body to adjust to the medication and minimise side effects like nausea.
Private pricing for Mounjaro in the UK typically ranges from £129 to £180 per month at 2.5mg, depending on the provider and whether you're buying a full KwikPen (which contains 4 weeks of doses). Some online clinics offer the 2.5mg dose at the lower end of this range.
- NHS access: Currently only available through specialist tier 3 weight management services — not standard GP prescription. Availability varies significantly by region and waiting lists can be long.
- Private access: Available through UK-licensed online prescribers following a clinical assessment. No NHS referral required.
- Eligibility: Adults with BMI ≥30, or BMI 27–29.9 with weight-related conditions like type 2 diabetes or hypertension, may qualify after assessment.
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.
How the 2.5mg Dose Fits Into Your Treatment Plan
The 2.5mg starter dose is never a long-term maintenance dose — it's a stepping stone. Your prescriber will typically increase your dose every 4 weeks: 2.5mg (weeks 1–4) → 5mg (weeks 5–8) → 7.5mg or higher as needed. Most people find therapeutic benefit at higher doses (10–15mg), so the 2.5mg cost is a short-term investment.
If you're looking for the absolute cheapest entry point to tirzepatide treatment, compare prices across UK-licensed online pharmacies after your prescription is issued. Prices can vary by £20–£50 per pen depending on the provider. Use our free GLP-1 weight loss calculator above to estimate projected weight loss at different doses — this can help you understand whether the cost aligns with realistic expectations.
The 2.5mg starter dose is never a long-term maintenance dose — it's a stepping stone. Your prescriber will typically increase your dose every 4 weeks: 2.5mg (weeks 1–4) → 5mg (weeks 5–8) → 7.5mg or higher as needed. Most people find therapeutic benefit at higher doses (10–15mg), so the 2.5mg cost is a short-term investment.
If you're looking for the absolute cheapest entry point to tirzepatide treatment, compare prices across UK-licensed online pharmacies after your prescription is issued. Prices can vary by £20–£50 per pen depending on the provider. Use our free GLP-1 weight loss calculator above to estimate projected weight loss at different doses — this can help you understand whether the cost aligns with realistic expectations.
- 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 2.5mg Mounjaro the cheapest dose available?
Yes, 2.5mg is typically the lowest-priced dose because it's the starting dose and requires the shortest duration at that strength. Most people move to higher doses (5–15mg) within weeks. However, cost per dose varies by provider — always compare prices across multiple UK-licensed pharmacies before purchasing.
Can I stay on 2.5mg Mounjaro long-term?
No. Clinical guidelines recommend increasing your dose every 4 weeks to find your therapeutic dose. Staying on 2.5mg longer than 4–8 weeks is unusual unless side effects are severe. Higher doses (10–15mg) typically produce better weight loss results based on clinical trial data.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist; Wegovy (semaglutide) is a GLP-1 agonist only. Mounjaro's 2.5mg starting dose is different from Wegovy's 0.25mg starter. Both require prescription and clinical assessment. Mounjaro may offer slightly stronger weight loss results in trials, but individual responses vary significantly.
Do I need a prescription to buy 2.5mg Mounjaro in the UK?
Yes. Mounjaro is prescription-only and requires a clinical assessment from a UK-licensed prescriber. You cannot purchase it over the counter. Assessment can be done online through accredited clinics; if approved, your prescription is then dispensed by a GPhC-registered pharmacy.
What eligibility criteria apply for 2.5mg Mounjaro?
You may be eligible if you have a BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, sleep apnoea, cardiovascular disease, or dyslipidaemia). A prescriber will assess your suitability during your consultation. Use our free BMI calculator above to check your BMI instantly.
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.