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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Understanding 5 Mg Dosing for Weight Loss in the UK
A 5 mg dose is a common starting or maintenance point for weight loss medications in the UK health system. If you're exploring prescription weight management options or have been prescribed a 5 mg injection, understanding what this dose means, how it works, and whether it's right for your situation is essential. This guide covers UK-specific guidance, NHS policy, and practical next steps to help you make informed health decisions.
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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.
5 Mg in UK Weight Loss Treatment
The 5 mg dose appears across different UK-licensed weight loss medications. Mounjaro (tirzepatide) uses 5 mg as a first maintenance dose after the initial 2.5 mg starting phase, typically reached at week 5. Saxenda (liraglutide), the daily injection alternative, uses a cumulative approach rather than discrete mg steps. The 5 mg threshold represents a significant escalation point where many patients begin to experience meaningful appetite reduction and metabolic effects.
- At 5 mg Mounjaro, clinical data suggests an average weight loss of approximately 15% body weight when combined with dietary changes and physical activity
- Individual responses vary considerably based on genetics, baseline health, adherence, and lifestyle factors
- Your GP or prescriber will assess whether this dose is appropriate for your personal health profile and weight loss goals
- The dose may be increased further to 7.5 mg, 10 mg, or higher depending on tolerability and response
Always follow your prescriber's guidance on dosing and never adjust doses without medical advice. Use our free BMI calculator to track how your weight management progresses at any dose level.
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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.
NHS Guidance and UK Access to 5 Mg Dosing
In the UK, access to weight loss medications like 5 mg Mounjaro is regulated through NHS specialist tier 3 services or private online prescribing following clinical assessment. NICE guidelines support the use of GLP-1 and GIP/GLP-1 medications for adults with BMI 30 or above, or BMI 27–29.9 with weight-related health conditions such as type 2 diabetes, hypertension, or cardiovascular disease.
- NHS access varies significantly by region and often involves waiting lists
- Private prescribers can assess eligibility and issue prescriptions without NHS referral
- All prescriptions require an online or in-person clinical assessment to ensure safety
- Your GP can provide personalised advice on whether medication at this dose is suitable for your situation
Calculate your personal BMI using our free BMI calculator to understand whether you meet eligibility thresholds in your region.
- 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.
What does a 5 mg dose of Mounjaro actually do in your body?
A 5 mg dose activates GIP and GLP-1 hormone pathways, signalling fullness to your brain, slowing stomach emptying, and supporting reduced appetite. This typically leads to eating smaller portions and reduced food cravings. Effects develop gradually over the first 4 weeks at this dose.
Is 5 mg the maximum dose for weight loss medication in the UK?
No. 5 mg is often a starting maintenance dose. Mounjaro can be escalated to 7.5 mg, 10 mg, 12.5 mg, and up to 15 mg based on response and tolerability. Your prescriber will guide escalation if needed.
How much weight can you expect to lose at 5 mg in the UK?
Clinical trials show an average of around clinically studied weight loss at 5 mg Mounjaro when combined with reduced-calorie diet and increased activity. Individual results vary significantly. Some lose more, some less. Expect 3–6 months to see full effects.
Can I get 5 mg weight loss medication on the NHS in the UK?
Yes, through NHS specialist weight management services (tier 3) if you meet eligibility criteria. Access varies by region and involves clinical assessment. Private online prescribers also offer 5 mg doses following assessment, without NHS referral.
What happens if 5 mg isn't working — can it be increased?
Yes. If you tolerate 5 mg well but weight loss plateaus, your prescriber may increase to 7.5 mg or higher. Escalation requires at least 4 weeks at each dose to assess full effect. Discuss concerns with your prescriber before any dose change.
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.