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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Weight Loss on 5mg Mounjaro in the UK
5mg Mounjaro is the starting dose used during the first month of treatment with this weekly weight loss injection. At this stage, most people are still in the adjustment phase, so significant weight loss may not yet be visible—but this dose helps your body adapt to the medication. If you're wondering about access and cost in the UK, there are two main routes: NHS specialist services or private prescription through a licensed online prescriber. This guide explains both pathways and what 5mg treatment typically costs.
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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.
Private Cost of 5mg Mounjaro in the UK
In the UK private market, a single 5mg Mounjaro KwikPen (one month's supply) typically costs between £130 and £180, depending on the provider and whether you're buying a single pen or a full course package. Some private clinics offer discounted rates for purchasing multiple pens upfront—for example, a 3-month course might cost £380–£450. Always check the total cost including the online consultation fee (usually £30–£50), as this is additional to the medication price.
- Single 5mg pen: approximately £130–£180
- 3-month supply: approximately £380–£450
- Consultation fee: typically £30–£50 (usually required at start only)
- Repeat prescriptions: often slightly cheaper after initial consultation
These prices vary between providers, so it's worth comparing. Use our GLP-1 weight loss calculator to estimate your potential results at 5mg, which may help you decide if the investment is right for you.
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 vs Private Access for Mounjaro
On the NHS, Mounjaro is approved by NICE for specialist weight management services (tier 3 or tier 4 care), but access is regional and waiting lists can extend from several months to over a year in many areas. You'll need a GP referral and a clinical assessment through your local weight management service—it's free once approved, but availability is limited.
Private prescription is faster: you have an online consultation with a UK-licensed prescriber, provide medical history, and receive a prescription within 24–48 hours if approved. No NHS referral needed. The prescription is dispensed by a GPhC-registered pharmacy. Your GP can provide context on which route suits your situation using our BMI calculator and health history.
The online consultation process is straightforward: you complete a health questionnaire covering weight history, medications, allergies, and medical conditions. A prescriber reviews your answers and assesses whether Mounjaro is appropriate. If approved, you'll receive your prescription and dosing instructions. Most people start at 2.5mg for the first week, then move to 5mg—this is the dose titration schedule MHRA guidelines require. Track your progress once you start using our free progress tracker, and use the weight converter if you prefer monitoring in stone and pounds.
- 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.
How much weight can I lose on 5mg Mounjaro?
5mg is the starting maintenance dose. Clinical trials show that at this dose, people lose an average of around 15% of their body weight over time, though individual results vary significantly. Weight loss typically continues as the dose increases. Results depend on diet, activity level, and individual metabolism. Your GP can give you personalised expectations.
Is Mounjaro available on the NHS for weight loss?
Yes, NICE has approved tirzepatide (Mounjaro) for NHS specialist weight management services. Access is through tier 3 or 4 services via GP referral, but availability is very limited and regional. Waiting lists are often long. Private prescription is typically faster if you want to start treatment sooner.
How does the private prescription process work?
You complete an online health questionnaire with a UK-licensed prescriber. They review your medical history and assess suitability. If approved, you receive a prescription, which is dispensed by a GPhC-registered pharmacy. The whole process usually takes 24–48 hours. Cost includes both the consultation and medication.
Can I switch from 5mg to a higher dose?
Yes. MHRA guidelines recommend staying on each dose for at least 4 weeks before increasing. Your prescriber will guide you through dose escalation based on your tolerance and response. The next step is typically 7.5mg after 4 weeks on 5mg, assuming you're tolerating it well.
What's the difference between 5mg Mounjaro and a weekly weight loss injection like Wegovy?
Both are once-weekly injections, but they work differently. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist—it activates two hormone pathways. Wegovy (semaglutide) is a GLP-1 agonist only. Mounjaro starts at 2.5mg/5mg, while Wegovy starts lower. Results vary between individuals. Your prescriber can discuss which is more suitable for you.
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.