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
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Why Mounjaro Isn't Suppressing Your Appetite
If you're taking Mounjaro and not noticing appetite suppression, you're not alone — individual responses to tirzepatide vary considerably. Appetite suppression is one of the key mechanisms of Mounjaro, but effectiveness depends on your dose, how long you've been taking it, how your body responds to the medication, and other factors. This guide explains what might be happening, the cost and access options for Mounjaro in the UK, and when to speak to your prescriber.
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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.
Why Appetite Suppression May Not Be Working
Individual variation is normal. Clinical trials show that Mounjaro helps most people feel fuller and eat less, but not everyone experiences appetite suppression immediately or at the same intensity. Several factors affect appetite response:
- Dose level: You may still be on a lower starting dose (2.5 mg or 5 mg). Appetite suppression often increases as you progress through dose titration towards 10 mg or higher.
- Time on medication: Your body may still be adjusting. Full effects typically emerge over 4–12 weeks of consistent use.
- Baseline eating patterns: If you were eating very little before starting, appetite suppression may be less noticeable than for someone with high baseline hunger.
- Underlying conditions: Certain medical conditions, stress levels, sleep quality, and other medications can influence how well appetite suppression works.
- Diet and activity: Mounjaro works best alongside reduced-calorie eating and increased physical activity — if diet hasn't changed, appetite effects may be less visible.
When to contact your prescriber: If you've been on a stable dose for 8+ weeks and see no appetite change, discuss this with your GP or specialist. They may adjust your dose, check for medication interactions, or explore other options.
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.
Mounjaro Cost and Access in the UK
NHS access: Mounjaro is available through specialist tier 3/4 weight management services on the NHS. You'll need a GP referral, and access varies significantly by region (Integrated Care Board). Waiting times can be several months in many areas, but there is no prescription cost once approved.
Private access: Available through GPhC-registered online prescribing services following a clinical consultation. Costs range from approximately £129–£280 per month depending on your dose and provider. A Mounjaro kwikpen contains 4 weekly doses. You can switch between NHS and private at any time, and your prescriber will manage the transition. Use our free GLP-1 weight loss calculator to understand potential outcomes before committing to private treatment.
Online prescription process: Private prescribers assess your eligibility through a confidential online questionnaire covering your medical history, BMI, weight-related health conditions, and current medications. If approved, your prescription is sent electronically to a UK pharmacy, which ships your Mounjaro kwikpen directly to you. Expect your first delivery within 3–5 working days. Each dose adjustment or refill requires a new assessment to ensure the medication remains appropriate.
Important considerations: Prescription costs do not include delivery (usually £3–£5). You should budget for ongoing monthly costs if continuing privately. Some people use private prescribing temporarily whilst waiting for NHS tier 3 services, then switch to NHS when available. Always inform your prescriber of any other medications, as Mounjaro may affect absorption of oral contraceptives and certain diabetes medications.
- 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.
If Mounjaro isn't suppressing my appetite, is it still working?
Appetite suppression is one mechanism, but Mounjaro also affects blood sugar regulation, how quickly food leaves your stomach, and fat utilisation. You may be experiencing subtle effects — like feeling satisfied sooner or having fewer cravings — without dramatic appetite loss. Weight loss can still occur even if appetite suppression feels mild. Discuss specific changes with your prescriber.
Will increasing my Mounjaro dose help if appetite suppression isn't working?
Possibly. If you're on a lower starting dose (2.5–5 mg), dose titration during weeks 1–20 may improve appetite response. However, if you're already on 10 mg or higher and see no appetite change after 8+ weeks, your prescriber may explore other factors — medication interactions, lifestyle factors, or underlying health conditions — before increasing further.
How much does Mounjaro cost privately in the UK each month?
Private Mounjaro costs typically range from £129–£280 per month depending on dose (2.5–15 mg) and the provider. A Mounjaro kwikpen contains 4 weekly doses. Costs vary because different online prescribing services have different pricing models. Add £3–£5 for delivery. NHS cost is zero once approved through specialist services, but waiting times vary by region.
Can I switch from private Mounjaro to NHS if I'm approved later?
Yes. You can pause private prescriptions and transition to NHS tier 3 services when your referral is approved. Your prescriber will coordinate the handover to ensure continuity of care. Some people use private treatment whilst waiting for NHS services, then switch to avoid costs. Inform both providers of the transition.
What if Mounjaro isn't suppressing appetite and I want to try Wegovy instead?
Switching between tirzepatide (Mounjaro) and semaglutide (Wegovy) is possible and may be worth discussing with your prescriber. Mounjaro uses a dual GIP and GLP-1 mechanism, whilst Wegovy uses GLP-1 only — some people respond better to one than the other. Switching requires a new prescription and clinical assessment. Compare costs and availability between your current provider and alternatives before deciding.
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.