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
What Is The Highest Dosage Of Mounjaro In The UK?
The highest dosage of Mounjaro (tirzepatide) available in the UK is 15mg once weekly. This is the maximum therapeutic dose, though most people start on a lower dose and gradually increase over several months. Dose titration is a carefully managed process where your prescriber adjusts your dose every 4 weeks based on your response and any side effects. Understanding how dosing works helps you know what to expect if you're eligible for this prescription-only weight management injection through NHS specialist services or private prescribing in the UK.
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.
How Mounjaro Dosing Works In The UK
Mounjaro dose titration follows a structured escalation schedule. You begin on 2.5mg weekly for 4 weeks, then increase to 5mg for weeks 5–8. From there, your prescriber may escalate to 7.5mg, 10mg, 12.5mg, and finally 15mg—with a minimum of 4 weeks on each dose before increasing. This gradual approach allows your body to adjust and helps your prescriber identify the effective dose for you.
Why start low? The tirzepatide KwikPen device delivers precise doses, and starting with a lower strength reduces initial nausea and digestive side effects, which are very common. Each KwikPen contains 4 weekly doses, so you'll use one pen per month at each dose level.
- 2.5mg — weeks 1–4 (starting dose)
- 5mg — weeks 5–8+ (first maintenance)
- 10mg — weeks 13–16+ (mid-range)
- 15mg — week 21+ (maximum dose)
Not everyone reaches 15mg. Your GP or specialist prescriber will work with you to find your optimal dose—the one that provides good weight management results with tolerable side effects.
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.
Mounjaro Maximum Dose And NHS Eligibility In The UK
Access to Mounjaro through the NHS in the UK is via tier 3 specialist weight management services. You'll typically need a GP referral, and eligibility is assessed based on BMI and weight-related health conditions. Use our free BMI calculator above to check your starting point.
NICE has approved tirzepatide for NHS specialist services, but availability varies significantly by region. Some areas have long waiting lists. Private prescribing offers faster access without NHS referral—a licensed UK prescriber can assess your suitability and issue a prescription, which is then dispensed by a GPhC-registered pharmacy.
Whether you reach the 15mg highest dosage depends on your individual response, tolerance, and clinical need. Your prescriber won't automatically escalate you to maximum dose; they'll stop at the dose that works best for you.
- 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 15mg Mounjaro the standard dose everyone gets?
No. The 15mg highest dosage is the maximum available, but most people stabilise at lower doses like 5mg or 10mg. Your prescriber will titrate you gradually and may stop escalating once you achieve good weight management results with manageable side effects. Individual response varies significantly.
How long does it take to reach the highest Mounjaro dose?
It takes a minimum of 20–21 weeks to reach 15mg if you escalate at every available step (4 weeks per dose level). However, many people don't escalate past 10mg. Your prescriber will adjust the timeline based on your tolerance and results.
Can I get Mounjaro at the highest dose on the NHS in the UK?
Potentially, yes—if you're eligible and referred to a tier 3 specialist weight management service. However, NHS availability varies by region and waiting lists can be substantial. Private prescribing offers more immediate access to Mounjaro dose titration through a UK-licensed prescriber.
What happens if I can't tolerate the highest Mounjaro dose?
Your prescriber will keep you on a lower dose that works for you. Common side effects like nausea often reduce over time as your body adjusts. If side effects remain problematic, you may stay at 5mg or 10mg—these doses still provide meaningful weight management results in clinical trials.
Does Mounjaro vs Wegovy mean different maximum doses?
Yes. Mounjaro's highest dose is 15mg weekly, while Wegovy (semaglutide) maxes out at 2.4mg weekly. They work differently—Mounjaro is a dual GIP plus GLP-1 agonist, while Wegovy is GLP-1 only. Your prescriber will recommend which is more suitable for you based on your health profile.
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.