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
When To Increase Your Mounjaro Dose
If you're taking Mounjaro (tirzepatide) for weight management in the UK, your prescriber will follow a specific dose increase schedule to help your body adjust safely. Mounjaro starts at a low dose and gradually increases over weeks, with each dose step designed to minimise side effects whilst maximising effectiveness. Understanding when and why dose increases happen helps you prepare for what to expect and work with your healthcare team effectively.
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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.
Mounjaro Dose Titration Schedule in the UK
Mounjaro follows a structured 4-week dose escalation schedule. You start on 2.5 mg once weekly, then move to 5 mg, 7.5 mg, 10 mg, 12.5 mg, and finally 15 mg—the maximum dose. Each dose is held for a minimum of 4 weeks before increasing, allowing your body to adjust and your prescriber to assess how well you're responding.
- Week 1–4: 2.5 mg (starting dose)
- Week 5–8: 5 mg (first escalation)
- Week 9–12: 7.5 mg
- Week 13–16: 10 mg
- Week 17–20: 12.5 mg
- Week 21+: 15 mg (maximum maintenance dose)
Your prescriber may pause at any dose if you're experiencing significant side effects or achieving good results. Not everyone needs to reach 15 mg—the goal is finding the right dose for your body and health goals. Use our free GLP-1 weight loss calculator to explore how different doses may affect potential weight loss outcomes.
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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.
Accessing Mounjaro in the UK: NHS vs Private Routes
In the UK, accessing Mounjaro requires a prescription from a licensed healthcare professional. If you're referred through the NHS, you'll be assessed by a specialist weight management service—but waiting lists can be lengthy in many regions, and availability varies significantly by area.
Alternatively, private online prescribing services offer faster access. You'll complete an online clinical assessment with a UK-licensed prescriber who reviews your medical history, BMI, and weight-related health conditions. If suitable, a prescription is issued and dispensed by a GPhC-registered pharmacy. Private costs vary by dose and provider, typically ranging from £129–£320 monthly. Always ensure any service you use is regulated and staffed by qualified UK healthcare professionals before starting treatment.
- 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.
Can I request a faster dose increase than the standard schedule?
No. The 4-week minimum between doses is a safety requirement set by the UK regulator. This schedule gives your body time to adjust and helps your prescriber assess tolerance and effectiveness. Faster increases increase the risk of severe nausea, vomiting, and other side effects. Your prescriber can only adjust the timeline based on your individual response.
What if I don't see weight loss results at a lower dose—should I increase sooner?
Not necessarily. Weight loss can take 8–12 weeks to become noticeable at each dose level. Your prescriber monitors your progress and will increase your dose if clinically appropriate at the 4-week mark. Use our free progress tracker to log changes in weight, energy, and appetite—sometimes improvements appear before the scales shift.
Is there a difference between Mounjaro and Wegovy dose schedules?
Yes. Mounjaro (tirzepatide) escalates from 2.5 mg to a maximum of 15 mg weekly. Wegovy (semaglutide), a different GLP-1 medication, starts at 0.25 mg and escalates to 2.4 mg weekly. Both follow 4-week intervals, but the starting doses and maximum doses are different. Your prescriber chooses the appropriate medication and schedule for your individual needs.
What happens if I miss a weekly Mounjaro injection during dose escalation?
If you miss a dose within 4 days, inject as soon as you remember and resume your normal schedule. If more than 4 days have passed, skip that dose and return to your regular injection day—never double-dose. Ensure at least 72 hours passes between injections. Contact your prescriber if you're unsure about timing.
Can I stop at a lower dose if 15 mg works for me?
Yes. Mounjaro is individualised—your prescriber aims to find the dose that works best for your body and goals, not necessarily the maximum dose. Some people achieve good results at 10 mg or 12.5 mg and stay there long-term. Weight loss effectiveness and tolerability matter more than reaching the highest dose 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.