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
Can I Eat Steak on Mounjaro?
Yes, you can eat steak while taking Mounjaro, but portion sizes typically become smaller due to reduced appetite. Mounjaro (tirzepatide) works by helping you feel fuller faster and reducing food cravings — it doesn't restrict specific foods. However, high-fat foods like steak may cause side effects in some people, particularly nausea or digestive discomfort. Many users find they naturally eat less meat overall simply because the medication reduces hunger signals. Your GP or prescriber can give you personalised dietary guidance based on your individual tolerance and health needs.
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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.
How Mounjaro Affects Your Diet and Food Choices
Mounjaro works as a dual GIP and GLP-1 receptor agonist, meaning it activates two natural hormone pathways that regulate appetite and satiety. This doesn't mean you must avoid steak or any specific food — instead, most users experience dramatically reduced portion sizes and less frequent hunger.
In practice, many people find that foods they previously enjoyed become less appealing, or they can only manage a smaller amount. A steak that once seemed normal may now feel like too much food. The medication slows gastric emptying (how quickly food leaves your stomach), which contributes to prolonged fullness.
- Protein is still important: Red meat like steak is nutrient-dense and provides iron and B vitamins — there's no reason to eliminate it unless you experience side effects
- Fat content matters: Fatty cuts may increase nausea or digestive symptoms in some users, particularly in the first weeks of treatment
- Listen to your body: If steak causes discomfort, try leaner cuts or smaller portions — you'll naturally eat less on Mounjaro anyway
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.
Cost and Access: Getting Mounjaro in the UK
Mounjaro is a prescription-only medicine available in the UK through two main routes: NHS specialist services or private prescribing. On the NHS, access is through tier 3 specialist weight management services via GP referral — availability varies significantly by region, and waiting times can be substantial. Privately, you can obtain a prescription following an online clinical assessment with a UK-licensed prescriber, typically costing £129–£320 per month depending on your dose.
The KwikPen delivery device comes with 4 doses (4 weeks' supply). Private providers generally include the medication cost in their pricing. When comparing Mounjaro vs Wegovy costs, Mounjaro is often similarly priced to Wegovy private prescriptions, though this varies by provider. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses — this can help you decide if prescription treatment is right for you.
- 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.
Will Mounjaro stop me eating steak completely?
No. Mounjaro doesn't forbid any foods — it reduces hunger and portion sizes. Most people naturally eat less overall, including less meat. You may find you enjoy a smaller steak or eat it less frequently, but the choice remains yours.
Can fatty foods like steak cause side effects on Mounjaro?
High-fat foods can trigger nausea, indigestion, or diarrhoea in some users, particularly when starting Mounjaro or increasing doses. If steak causes discomfort, try leaner cuts, smaller portions, or eat it less frequently. Side effects often improve over time.
How do I access Mounjaro in the UK — NHS or private?
NHS access requires GP referral to a specialist weight management service (tier 3) — availability and waiting times vary by region. Privately, you can get a prescription after an online assessment with a UK-licensed prescriber through a GPhC-registered pharmacy, typically costing £129–£320 monthly depending on dose and provider.
Is Mounjaro the only GLP-1 injection available in the UK?
No. Other GLP-1 and GIP/GLP-1 medications are licensed in the UK, including Wegovy (semaglutide) and Saxenda (liraglutide). Mounjaro is unique as a dual GIP+GLP-1 agonist, which may offer slightly different effects. Your prescriber will advise which is suitable for you.
What happens if I stop taking Mounjaro — will appetite return?
Yes. Once you stop Mounjaro, appetite typically returns to baseline within a few weeks. This is why lifestyle changes — diet and physical activity — are important alongside medication. Many people continue the habits they've built while on Mounjaro to maintain weight loss.
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.