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
Mounjaro Pen 10mg — What You Need to Know
The Mounjaro 10mg pen is a mid-range dose used during the escalation phase of tirzepatide treatment. This prescription-only weight management injection contains the GIP and GLP-1 receptor agonist tirzepatide, which may help reduce appetite and support weight loss alongside a reduced-calorie diet and physical activity. The 10mg dose is typically reached around weeks 13–16 of treatment and represents the third escalation step. Understanding how the 10mg dose works and what to expect can help you manage your weight loss journey effectively.
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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 the 10mg Dose Fits Into Mounjaro Treatment
Mounjaro treatment follows a dose titration schedule, starting at 2.5mg and increasing every 4 weeks to allow your body to adjust. The 10mg dose is reached around week 13 and sits between the 7.5mg and 12.5mg doses in the escalation pathway. Most people experience the drug's appetite-reducing effects throughout this phase, though individual responses vary significantly. Clinical trials showed that at the 10mg dose, Mounjaro may support weight loss of approximately 19–20% of body weight over 72 weeks, though this is an average and results depend on diet, activity level, and individual factors. You can use our GLP-1 weight loss calculator to estimate potential outcomes at different doses. This dose is administered once weekly via the KwikPen auto-injector.
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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.
Side Effects and Tolerability at 10mg
At the 10mg dose, the most commonly reported side effects include nausea, diarrhoea, constipation, and stomach discomfort—typically milder than when first starting Mounjaro, as most people have already adjusted during the lower dose phases. Some users report fatigue or reduced appetite as side effects settle. Serious side effects are rare but include severe stomach pain (possible pancreatitis), gallbladder issues, or serious allergic reactions—seek immediate medical attention if these occur. If side effects remain bothersome at 10mg, discuss with your prescriber whether continuing escalation is appropriate 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.
Is Mounjaro 10mg the maximum dose?
No. The 10mg dose is a mid-range escalation step. The maximum dose is 15mg, typically reached around week 21. Most people escalate through 7.5mg, 10mg, 12.5mg, and finally 15mg, spending at least 4 weeks on each dose.
Can I stay on Mounjaro 10mg indefinitely?
Yes, if your prescriber agrees it's working well for you and side effects are manageable. You don't have to continue escalating to the maximum dose. Treatment is ongoing and should be reviewed regularly with your GP or weight management specialist.
How does the 10mg Mounjaro pen work exactly?
Mounjaro activates two hormone pathways—GIP and GLP-1—to reduce appetite, support feeling fuller, and slow gastric emptying. The dual mechanism may be more effective than single-pathway medications, though individual results vary significantly.
What's the difference between Mounjaro 10mg and Wegovy at equivalent doses?
Mounjaro (tirzepatide) uses a dual GIP/GLP-1 mechanism, while Wegovy (semaglutide) is GLP-1-only. Clinical trials suggest Mounjaro may produce slightly higher average weight loss, but both are effective. Your prescriber will determine which is suitable for you.
How do I know if I'm eligible for Mounjaro in the UK?
You're typically eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or high blood pressure. Eligibility is assessed during a clinical consultation with a prescriber or NHS specialist service.
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.