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
What to Expect From a Mounjaro Consultation in the UK
A Mounjaro consultation is a medical assessment to determine whether tirzepatide is suitable for you. In the UK, you'll need a consultation with either an NHS specialist weight management service or a private prescriber before being prescribed Mounjaro. The consultation evaluates your health history, current weight, BMI, and any weight-related conditions to assess eligibility and ensure the medication is safe for your individual circumstances.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
How Mounjaro Consultations Work in the UK
NHS consultations take place through tier 3 specialist weight management services, usually following a GP referral. You may wait several months for an appointment depending on your area. The specialist team will review your medical history, discuss your weight loss goals, and assess whether you meet NICE eligibility criteria (typically BMI ≥30, or BMI ≥27 with weight-related health conditions). Private consultations are conducted online with UK-licensed prescribers and usually take 15–30 minutes. You'll answer questions about your health, current medications, family medical history, and any contraindications like previous pancreatitis or thyroid cancer. The prescriber may request recent blood tests or ask about your diet and exercise habits. If approved, a prescription for Mounjaro KwikPen is issued and dispensed by a GPhC-registered pharmacy. Both routes require assessment before prescription—Mounjaro is prescription-only and cannot be obtained without clinical evaluation.
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.
What You'll Need to Prepare for Your Consultation
Gather key information before your appointment: your current weight and height (to calculate BMI), any weight-related health conditions (type 2 diabetes, hypertension, sleep apnoea, cardiovascular disease), all current medications and supplements, and your medical history including allergies and any previous adverse reactions to medications. Write down your weight loss goals and any questions. Use our free BMI calculator above to know your current BMI before the consultation—this helps you understand whether you meet eligibility criteria. If you're taking oral contraceptives, mention this, as Mounjaro may affect absorption. Be honest about diet, exercise level, and previous weight loss attempts. For private consultations, have your details ready for an online assessment form.
- 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 happens if I'm not eligible for Mounjaro on the NHS?
If you don't meet NHS tier 3 criteria, you can access Mounjaro privately through online prescribing services. Eligibility is assessed individually, and a private prescriber may reach a different conclusion than NHS services. Private treatment costs vary but typically ranges from £129–£320 monthly depending on dose.
Do I need blood tests before starting Mounjaro?
It varies. NHS services often request baseline blood tests to check kidney function, liver health, and blood sugar levels. Private prescribers may request tests or rely on your health questionnaire. Some recommend fasting glucose tests if you have diabetes risk factors. Ask your prescriber what's needed.
How long does a Mounjaro consultation take?
NHS consultations typically last 30–60 minutes and cover detailed medical history, lifestyle assessment, and goal-setting. Private online consultations are usually 15–30 minutes focused on health screening and tirzepatide suitability. Follow-up consultations for dose adjustments are generally shorter.
What should I tell my doctor about my diet and exercise?
Be honest about your current lifestyle. Describe your typical daily diet, eating habits, and triggers for overeating. Mention any physical activity you do. Mounjaro works best alongside reduced-calorie diet and increased activity, so your prescriber needs realistic baseline information to set appropriate expectations.
Can I get Mounjaro without a consultation?
No. Mounjaro is prescription-only in the UK and legally requires a clinical consultation with a licensed prescriber—either NHS or private. Any legitimate provider will conduct a proper health assessment before issuing a prescription. This protects your safety.
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.