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 and Dementia — What the NHS Evidence Shows
There is no evidence that Mounjaro (tirzepatide) increases dementia risk in adults. In fact, some research suggests that weight loss and better blood sugar control may help reduce dementia risk. If you're considering Mounjaro as part of your weight management plan, dementia risk is not a clinical concern based on current NHS guidance. However, like all prescription medications, Mounjaro should only be used following a clinical assessment by your GP or a licensed prescriber. Our free BMI calculator can help you understand your current weight status and whether you might be eligible for treatment under NHS criteria.
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.
Clinical Evidence and NHS Safety Data
Mounjaro has not been linked to dementia risk in clinical trials or real-world safety monitoring. The SURMOUNT trials (the main clinical studies for tirzepatide) did not show any increased risk of cognitive decline or dementia in adult participants. The MHRA, which monitors all prescription medicines in the UK, has not raised any dementia concerns with Mounjaro, and NICE guidance does not flag dementia as a safety issue.
Interestingly, maintaining a healthy weight may actually help reduce dementia risk. Research shows that obesity and poorly controlled blood sugar (type 2 diabetes) are both associated with increased dementia risk. By helping you lose weight and improve metabolic health, Mounjaro may indirectly support brain health. If you have type 2 diabetes or prediabetes alongside excess weight, improving these conditions through weight loss could be protective.
- MHRA safety monitoring shows no dementia link
- SURMOUNT trials found no cognitive decline signals
- Weight loss itself may reduce dementia risk factors
- Better blood sugar control supports brain health
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.
NHS Prescribing Safety and What to Tell Your GP
If you're assessed for Mounjaro through an NHS specialist tier 3 weight management service, the assessing clinician will review your full medical history, including any family history of dementia or other neurological conditions. There are no contraindications related to dementia risk.
When discussing Mounjaro with your GP or specialist, mention any concerns you have about cognitive health or family history of neurological conditions. Your prescriber can reassure you based on current evidence and monitor you appropriately during treatment. Use our GLP-1 weight loss calculator to explore potential weight loss projections, and our weight converter to track your progress in kilograms or stone.
- Tell your healthcare team about any cognitive health concerns
- Dementia risk is not a reason to avoid Mounjaro
- Weight loss benefits may protect against cognitive decline
- 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.
Does Mounjaro cause dementia?
No. There is no evidence in clinical trials or NHS safety monitoring that Mounjaro (tirzepatide) causes or increases dementia risk. The MHRA has found no safety signals linking tirzepatide to cognitive decline or dementia in any patient group.
Can weight loss with Mounjaro help prevent dementia?
Possibly. Research shows that maintaining a healthy weight and controlling blood sugar reduces dementia risk factors. By helping you achieve weight loss and improve metabolic health, Mounjaro may indirectly support cognitive health, especially if you have type 2 diabetes or prediabetes.
Should I avoid Mounjaro if there's dementia in my family?
No. Family history of dementia is not a contraindication for Mounjaro. There is no evidence that tirzepatide increases risk in people with a family history. However, always discuss your full medical history, including family health conditions, with your GP or prescriber before starting any medication.
What should I tell my NHS prescriber about dementia concerns?
Tell your GP or specialist if you have concerns about cognitive health or family history of neurological conditions. They can review current safety data and reassure you. Your prescriber will monitor you throughout treatment and can address any questions about brain health.
Is dementia listed as a side effect of Mounjaro in the UK?
No. Dementia or cognitive decline is not listed as a known side effect of Mounjaro in the MHRA product information or NHS guidance. Common side effects relate to the digestive system (nausea, diarrhoea), not cognitive or neurological effects.
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.