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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What Is Mounjaro 7.5 Mg and When Is It Used?
Mounjaro 7.5 mg (tirzepatide) is the third escalation dose in the UK weight management pathway. This dose is reached after a minimum 4-week period on the 5 mg dose, assuming good tolerance. At 7.5 mg, the dual GIP and GLP-1 mechanism continues to support appetite regulation and fuller feelings after meals. Individual response varies significantly — some people reach their weight loss goals at lower doses, whilst others require further escalation to 10 mg or the maximum 15 mg. Your prescriber will assess your progress and tolerance before recommending whether to continue at 7.5 mg or increase further.
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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 7.5 Mg vs Wegovy: Mechanism and Trial Data
Mounjaro (tirzepatide) at 7.5 mg activates two hormone pathways simultaneously: GIP and GLP-1. The SURMOUNT-1 clinical trial showed that at intermediate doses around this level, tirzepatide supports meaningful weight loss alongside a reduced-calorie diet and increased physical activity.
Wegovy (semaglutide) activates GLP-1 only. The equivalent dose would be approximately 1.7 mg, which is the third escalation dose in the Wegovy pathway. STEP trial data showed semaglutide at this level produces significant weight loss results.
- Mounjaro: dual GIP + GLP-1 mechanism
- Wegovy: single GLP-1 mechanism only
- Both are once-weekly injections
- Individual results vary considerably
- Both require a clinical assessment before prescription
Clinical trials suggest the dual mechanism of Mounjaro may offer greater average weight loss, but response is highly individual. Your prescriber will determine which medication suits your specific health profile.
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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.
Suitability and Prescriber Assessment
Neither Mounjaro 7.5 mg nor Wegovy is suitable for everyone. Eligibility in the UK includes adults with a BMI of 30 or above, or 27–29.9 with weight-related conditions such as type 2 diabetes, hypertension, or cardiovascular disease. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply.
At 7.5 mg, Mounjaro is typically well-tolerated, though nausea, diarrhoea, and constipation remain possible. Your GP or prescriber will review your tolerance at each dose level and adjust accordingly. Using our GLP-1 weight loss calculator can help you explore potential outcomes at different doses, though actual results depend on individual factors, diet, and physical activity.
- 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 Mounjaro 7.5 mg the maximum dose?
No. 7.5 mg is the third escalation dose. The maximum licensed dose is 15 mg once weekly. Your prescriber will increase your dose only if you tolerate lower doses well and require additional support for weight management.
How long do you stay on Mounjaro 7.5 mg before increasing?
A minimum of 4 weeks. Your prescriber will assess your weight loss progress, tolerance, and any side effects before recommending an increase to 10 mg. Some people stay at 7.5 mg long-term if they reach their goals.
What is the Wegovy equivalent to Mounjaro 7.5 mg?
Approximately 1.7 mg. This is approximate only — there is no official conversion chart. Any switch between medications must be managed by your prescriber, not done independently.
Does Mounjaro 7.5 mg work better than Wegovy?
Clinical trials suggest tirzepatide (Mounjaro) may produce greater average weight loss due to its dual mechanism, but individual results vary significantly. Suitability depends on your health profile, not just trial averages. Your prescriber will advise which is appropriate for you.
Can I buy Mounjaro 7.5 mg without a prescription?
No. Mounjaro is prescription-only in the UK. You need a prescription from a licensed GP or prescriber following a clinical assessment. It is available through NHS specialist weight management services or private GPhC-registered pharmacies with an online prescription.
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.