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
How Much Is Mounjaro 5 Mg in the UK?
Mounjaro 5 mg is the first maintenance dose of tirzepatide available through the NHS and private prescription in the UK. This dose typically costs between £150–£200 privately per month, though prices vary by provider. On the NHS, the cost to the service is covered but availability depends on your local integrated care board (ICB) and specialist tier 3 weight management services. The 5 mg dose is reached after four weeks of starting at 2.5 mg, and represents the first step where most people begin to see meaningful weight loss effects in clinical trials.
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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.
Mounjaro 5 Mg — NHS Eligibility and Prescription Route
Access via the NHS: Mounjaro is available through specialist tier 3 weight management services, not as a standard GP prescription. Your GP can refer you to your local service if you meet NICE eligibility criteria: a BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, sleep apnoea, cardiovascular disease). For South Asian, Chinese, Black African, and Black Caribbean adults, lower thresholds apply from BMI 27.5.
NICE guidance: NICE approved tirzepatide (Mounjaro's active ingredient) for NHS use in specialist weight management services. However, waiting lists are lengthy in many regions—some areas have 12–24 month waits. Regional variation is significant; some ICBs have limited or no access yet.
Dose progression: You start at 2.5 mg weekly for weeks 1–4, then increase to 5 mg for weeks 5–8. This gradual titration helps your body adjust and minimises gastrointestinal side effects, which are most common at the start.
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.
Mounjaro 5 Mg — Private Prescription and Costs
Private prescriptions for Mounjaro are available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. A 5 mg KwikPen (which contains four weekly injections) typically costs £150–£200 depending on the pharmacy. Private access bypasses NHS waiting lists entirely, though clinical assessment remains mandatory to ensure the medication is appropriate for your health profile.
Compare costs carefully: some providers offer subscription discounts for regular orders, while others charge per-pen. Always verify the pharmacy is registered with the GPhC. If you're considering private access, our free GLP-1 weight loss calculator can help you estimate potential outcomes at the 5 mg dose and beyond based on clinical trial data.
- 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 5 mg available on the NHS?
Yes, Mounjaro (tirzepatide) is approved by NICE for use in NHS specialist tier 3 weight management services. Access is through these specialised services, not standard GP prescription. Availability and waiting times vary significantly by region and local ICB funding.
What's the difference between 5 mg and other Mounjaro doses?
Mounjaro comes in doses from 2.5 mg to 15 mg weekly. The 5 mg dose is the first maintenance dose; clinical trials showed approximately 15% average body weight loss at this level, increasing to 19–21% at higher doses. Individual results vary significantly.
How much does Mounjaro 5 mg cost privately in the UK?
Private Mounjaro 5 mg costs approximately £150–£200 per KwikPen (four weekly injections) through UK-registered online pharmacies. Prices vary by provider and may include subscription discounts. Always use a GPhC-registered pharmacy.
Can I switch from Wegovy to Mounjaro 5 mg?
Yes, some people switch from Wegovy (semaglutide) to Mounjaro (tirzepatide) because Mounjaro uses a dual GIP and GLP-1 mechanism. Approximate equivalence is Wegovy 0.5 mg ≈ Mounjaro 5 mg, but any switch must be managed by your prescriber.
What side effects should I expect at the 5 mg dose?
Common side effects at 5 mg include nausea, diarrhoea, vomiting, and constipation—usually mild at this dose because you've already titrated from 2.5 mg. Gastrointestinal effects typically improve over weeks 2–4. Serious side effects are rare but require immediate GP attention if severe stomach pain occurs.
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.