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
Moving Up to 5mg Mounjaro: Your UK Dose Escalation Guide
Moving up to 5mg Mounjaro is a standard part of dose escalation for most people starting the medication. After four weeks on the starting dose of 2.5mg, your prescriber will typically increase you to 5mg, which is usually the first maintenance dose. This guide explains what to expect during the escalation phase, how the dose increase works, and what NHS and private prescribing routes look like in the UK. If you've already checked your BMI or projected potential weight loss using our free GLP-1 weight loss calculator, understanding your dose schedule is the next important step.
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 Dose Escalation Works in the UK
Mounjaro dosing follows a structured titration schedule:
- Weeks 1–4: 2.5mg once weekly (starting dose)
- Weeks 5–8: 5mg once weekly (first escalation)
- Weeks 9–12: 7.5mg once weekly (if needed)
- Weeks 13–16: 10mg once weekly (if needed)
- Weeks 17–20: 12.5mg once weekly (if needed)
- Week 21+: 15mg once weekly (maximum dose)
You must stay on each dose for at least 4 weeks before increasing. Your prescriber will assess your tolerance and weight loss progress before escalating. Moving to 5mg is the critical second step in this tirzepatide journey — this is where most people experience more noticeable appetite reduction and early weight loss effects. Common side effects like nausea often decrease as your body adapts, though some people experience new or worsening nausea when the dose increases. Your prescriber will monitor your progress and may pause escalation if side effects are difficult to manage.
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 and Private Routes for Mounjaro in the UK
NHS access to Mounjaro is through specialist tier 3 or tier 4 weight management services. Your GP refers you to these services, and a specialist assesses whether you meet NICE eligibility criteria (BMI ≥30, or BMI ≥27 with weight-related health conditions). Once approved, the NHS provides the injections free, though waiting lists vary significantly by region and can extend several months in many areas.
Private prescribing is faster — you complete an online consultation with a UK-licensed prescriber, and if approved, you receive a prescription for a GPhC-registered pharmacy. Private costs typically range £129–£200 monthly depending on dose. Both routes require a clinical assessment before your first dose and ongoing prescriber oversight.
---COL_J_PROGRESS---Once you've moved to 5mg, track your progress using our free progress tracker — logging weekly weight, how you're feeling, and any side effects helps you and your prescriber make informed decisions about future dose increases.
- 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.
When should I move up to 5mg Mounjaro?
You should move to 5mg in week 5 (after completing 4 weeks on 2.5mg). Your prescriber will confirm the exact date with your injection schedule. Each Mounjaro KwikPen contains 4 doses, so one pen covers one month of treatment at the same dose.
What happens if I can't tolerate 5mg Mounjaro?
If side effects at 5mg are too severe, tell your prescriber immediately. Some people pause at 2.5mg longer than 4 weeks or stay at 5mg longer before escalating. Your prescriber may also recommend lifestyle adjustments — smaller portions, hydration, and anti-nausea strategies — before increasing further.
How much weight can I expect to lose at 5mg?
Clinical trials show variable results. At 5mg Mounjaro (weeks 5–8 of treatment), most people experience early weight loss, though results vary widely. Using our GLP-1 weight loss calculator can help estimate potential outcomes, but individual results depend on diet, exercise, metabolism, and other factors.
Is 5mg Mounjaro available on the NHS?
Yes — if you're prescribed Mounjaro through an NHS specialist weight management service, all doses including 5mg are provided free. Access requires referral from your GP and eligibility assessment. Private routes offer faster access but involve direct costs to you.
What should I do if I miss a 5mg injection?
If you miss your injection, take it within 4 days of the scheduled date and continue your normal schedule. If more than 4 days have passed, skip that dose and take your next scheduled injection. Never take two injections within 3 days to catch up.
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.