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 You Inject Mounjaro Above the Belly Button?
Yes, you can inject Mounjaro above the belly button. Mounjaro (tirzepatide) can be injected in three main areas: the stomach, upper thigh, and upper arm. The abdomen above the belly button is a common and approved injection site. Proper site rotation is important to prevent skin irritation and ensure consistent medication absorption. Understanding your injection options helps you use your Mounjaro KwikPen safely and comfortably throughout your treatment.
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.
Approved Mounjaro Injection Sites
Mounjaro can be injected in three NHS-approved locations on your body. The stomach (abdomen) is the most frequently used site — you can inject anywhere on your stomach, including areas above and around the belly button, as long as you avoid the area directly around your navel itself. The upper thigh (outer area) is another popular choice and offers convenience, especially if you're rotating sites regularly. The upper arm (outer area) is also approved, though you may need assistance to inject into this area safely. Each week, rotate to a different site or a different area within the same region to minimise skin irritation, lumps, and bruising at injection points. This rotation practice helps maintain healthy skin and supports consistent absorption of the medication over time.
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.
Practical Site Rotation Tips
When rotating Mounjaro injection sites, aim to use a different location each week — for example, upper abdomen week one, lower abdomen week two, upper thigh week three, then repeat. Keep at least one finger's width distance between injection sites to avoid hitting the same spot repeatedly. Avoid injecting directly into areas with scars, bruising, or hardened skin. If you develop lipohypertrophy (thickened fatty tissue) at a site, inform your prescriber — this can affect medication absorption. Store your Mounjaro KwikPen correctly between doses: unopened pens in the fridge at 2–8°C, or at room temperature below 30°C for up to 30 days after first use. Your GP or pharmacist can demonstrate the correct injection technique to ensure you're using your pen safely.
- 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 it safe to inject Mounjaro above the belly button?
Yes, it's completely safe to inject Mounjaro above your belly button. The approved abdominal injection area includes the stomach above, around, and below the navel — just avoid injecting directly into the belly button itself. Rotate sites weekly to prevent skin irritation.
What happens if I inject Mounjaro in the same spot every week?
Repeatedly injecting in the same spot can cause lipohypertrophy (thickened fatty tissue), bruising, and skin irritation. This may affect how well the medication absorbs. Site rotation every week helps maintain healthy skin and consistent medication delivery.
Can you inject Mounjaro through clothing?
No, Mounjaro should always be injected into clean, bare skin. Never inject through clothing or layers. Clean the injection site with an alcohol swab and allow it to dry before injecting to reduce infection risk.
Does the injection site affect how quickly Mounjaro works?
Mounjaro works the same way regardless of which approved site you use — stomach, thigh, or arm. However, consistent site rotation ensures even absorption over time and reduces the risk of skin complications that could affect future injections.
What should you do if you miss an injection site rotation?
If you accidentally inject twice in the same area, don't worry — simply resume proper rotation for your next dose. If you develop bruising, redness, or swelling at a site, wait until it's healed before injecting there again and inform your GP.
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.