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 Depression — UK Health Information
Mounjaro (tirzepatide) is a prescription-only weight management injection, and like all medications, it can affect mood in some people. While depression is not a common side effect listed in clinical trials, mood changes have been reported. This guide explains what the evidence shows, how to access Mounjaro in the UK, what it costs, and when to seek support if you're concerned about mood changes while taking this medication.
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.
What Does the Evidence Show About Mounjaro and Mood?
Clinical trials for Mounjaro (tirzepatide) did not list depression as a common side effect, though some users have reported mood changes during treatment. The relationship between weight loss medication and depression is complex: weight loss itself often improves mood and mental health, but gradual weight management, changes in appetite, or underlying health conditions can occasionally affect mood negatively.
- Depression is not listed as a "common" or "very common" side effect in the UK Summary of Product Characteristics
- Some users report mood changes, but this varies individually and may relate to rapid weight changes, nutrient absorption, or pre-existing mental health conditions
- Weight loss achieved through Mounjaro may improve mood and reduce depression symptoms in many people, particularly if obesity was contributing to low mood
- If you have a history of depression or mental health concerns, discuss this with your prescriber before starting tirzepatide
Your GP or prescriber should assess your mental health history as part of the clinical assessment before starting any weight loss medication.
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.
How to Access Mounjaro in the UK — Cost and Routes
In the UK, Mounjaro is available through two routes: NHS specialist services (if you meet eligibility criteria and your local service has capacity) or private prescription through online prescribing services. NHS access typically involves referral to a tier 3 specialist weight management service, which can have long waiting lists depending on your region. Private prescription costs range from approximately £129–£320 per month depending on your dose, with the starting dose (2.5 mg) generally at the lower end. Online consultations typically cost £20–£50. You'll need to complete a clinical assessment with a UK-licensed prescriber, who will review your medical history, including any mental health conditions, before deciding if Mounjaro is suitable for you. Costs vary by provider but are consistent across GPhC-registered pharmacies.
- 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.
Can Mounjaro cause depression?
Depression is not listed as a common side effect in clinical trials, though some users report mood changes. If you have a history of depression, discuss this with your prescriber before starting treatment. Weight loss itself often improves mood, but individual responses vary.
Should I tell my prescriber about depression before starting Mounjaro?
Yes, absolutely. Always inform your prescriber or GP about any mental health history, current depression, or medications you're taking for mood. This helps them assess whether Mounjaro is appropriate for you and monitor you appropriately during treatment.
What does Mounjaro cost in the UK on the NHS?
Mounjaro is available on the NHS through specialist tier 3 weight management services for eligible adults, but availability varies significantly by region and waiting lists can be lengthy. Ask your GP about your local NHS weight management service.
How much does private Mounjaro cost in the UK?
Private Mounjaro costs approximately £129–£320 per month depending on your dose. Online consultations typically cost £20–£50. You'll need a prescription from a UK-licensed prescriber following a clinical assessment, which is separate from the medication cost.
What's the difference between NHS and private Mounjaro access?
NHS access is free at the point of use but involves referral, waiting lists, and regional availability limitations. Private access is faster and doesn't require NHS referral but involves consultation and medication costs. Both require a clinical assessment confirming you're suitable for treatment.
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.