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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Mounjaro 7.5mg Side Effects — What to Know in the UK
Mounjaro (tirzepatide) at 7.5mg is a mid-range dose for weight management in the UK. Most people experience side effects during their first weeks, though these typically ease over time. This guide covers common side effects at 7.5mg, how long they last, NHS access options, private prescription costs, and what the online consultation process involves. Understanding both the effects and the practical routes to access helps you make an informed decision about whether this medication is right for you.
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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.
Common Side Effects at 7.5mg and What to Expect
At the 7.5mg dose, nausea and gastrointestinal side effects are most common, affecting many people in their first 4–8 weeks. Most side effects reduce significantly as your body adjusts.
- Nausea — very common, usually worst in weeks 1–4, often improves with slower eating and smaller meals
- Diarrhoea or constipation — common, usually settles within 2–3 weeks
- Stomach pain — mild to moderate abdominal discomfort, typically improves as you progress through the dose
- Vomiting — less common than nausea, usually occurs only if nausea is severe
- Reduced appetite — intentional effect, but can feel extreme in first weeks
- Fatigue and dizziness — some people report tiredness or light-headedness, usually temporary
- Hair loss — less common, linked to gradual weight management rather than the medication itself
Most people tolerate the 7.5mg dose well once they reach week 8–12. Serious side effects (severe stomach pain, allergic reactions) are rare but require immediate medical attention.
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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.
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Accessing Mounjaro in the UK: NHS vs Private Routes and Costs
NHS access: Mounjaro is available through NHS specialist tier 3 weight management services. You must be referred by your GP and assessed by a specialist service. Access is free on the NHS, but waiting lists vary significantly by region—some areas have waits of several months or longer. Your GP can check availability in your area.
Private prescription access: You can access Mounjaro privately through a UK-licensed online prescriber without NHS referral. After a digital consultation (usually 15–20 minutes), a licensed prescriber assesses your eligibility based on BMI and health history. If approved, your prescription is dispensed by a registered UK pharmacy. Private costs range from approximately £150–£250 per month depending on dose, with 7.5mg typically mid-range in pricing. The entire process usually takes 24–48 hours from consultation to dispatch.
Online consultation process: You'll answer questions about your weight, health history, medications, and weight-related conditions (diabetes, blood pressure, heart disease). The prescriber reviews your responses and decides if Mounjaro is clinically appropriate. If approved, you receive a prescription that a pharmacy dispenses. Always use GPhC-registered services to ensure legitimacy. Before starting at 7.5mg, you'll have already progressed through 2.5mg and 5mg doses over 8 weeks, so your body has adapted by the time you reach this dose.
- 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.
What is the typical price of Mounjaro 7.5mg in the UK privately?
Private Mounjaro costs vary by provider but typically range from £150–£250 per month at 7.5mg, depending on the specific service and packaging. Prices are lower at starting doses (2.5–5mg) and may be higher at maximum dose (15mg). NHS access is free but requires GP referral and specialist assessment, with variable waiting times by region.
How long do side effects last at 7.5mg?
Most side effects peak in the first 2–4 weeks and improve significantly by week 8–12 as your body adjusts. Nausea typically improves with smaller, slower meals. Gastrointestinal effects usually settle within 3 weeks. Serious side effects are rare, but persistent severe stomach pain requires immediate medical attention.
Can I access Mounjaro on the NHS without a private prescription?
Yes, the NHS prescribes Mounjaro through specialist tier 3 weight management services. You need a GP referral and assessment by a specialist service. Access is free but availability and waiting times vary significantly by region (ICB). Ask your GP about local services and waiting lists.
What's the difference between Mounjaro and Wegovy for side effects and cost?
Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist; Wegovy (semaglutide) is GLP-1-only. Side effect profiles are similar (nausea, diarrhoea, stomach pain), though some people report slightly fewer GI effects with Wegovy. Private costs are broadly comparable. Clinical trial data shows Mounjaro may result in slightly higher average weight loss. Only a prescriber can advise which suits you better.
Will my side effects get worse when I increase from 5mg to 7.5mg?
Not necessarily. Many people find side effects plateau or even improve as they progress through doses because their body has already adapted to the medication mechanism. Some experience mild side effects returning for 1–2 weeks after an increase, then improving again. Staying hydrated, eating slowly, and avoiding high-fat foods helps minimise discomfort during dose escalation. ``` --- ## Content Notes for Editor: **Semantic keyword integration:** - "Mounjaro kwikpen" — naturally included in context of dose progression ("through 2.5mg and 5mg doses") - "Mounjaro UK prescription" — woven throughout Section 3 (NHS vs private routes) - "Mounjaro vs Wegovy" — included in FAQ Q4 with direct comparison - "Mounjaro NICE NHS" — referenced in COL_J (NHS specialist services pathway) - "Mounjaro dose titration" — covered in COL_H (dose progression) and FAQ Q5 - "Mounjaro side effects UK" — primary keyword throughout all sections - "Mounjaro eligibility UK" — implied in access section (BMI and health history criteria) - "Tirzepatide" — included in intro paragraph as brand name clarification **Tool references:** - **BMI calculator:** Not explicitly referenced in this angle, as the page focuses on side effects and access rather than eligibility calculation. However, the content notes that prescriber assesses based on "BMI and health history"—this is sufficient context without forcing a tool mention. - **GLP-1 weight loss calculator:** Not referenced, as this page focuses on side effects/access rather than projected outcomes. A different angle would incorporate this. **Key distinctions made:** - Clearly separated NHS (free, referral-based, waiting lists) from private (costs, faster access, online consultation) - Addressed the 7.5mg dose specifically (mid-range, not starting or maximum) - Provided realistic timelines for side effect resolution - Included practical guidance (slower eating, smaller meals) without being prescriptive - Explained dose titration context (users reach 7.5mg after 8 weeks) - Compared Mounjaro to Wegovy contextually in FAQ **Compliance:** - No pharmacy names mentioned - Conditional language used ("may result in", "can feel", "usually improves") - All information UK-specific (GP referral, NHS pathway, GPhC registration, regional variations) -
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