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
Does Mounjaro Cause Low Blood Pressure?
Mounjaro (tirzepatide) is not typically associated with causing low blood pressure in clinical trials. However, some people experience blood pressure changes when using this prescription-only GIP and GLP-1 receptor agonist. Most commonly, Mounjaro may actually help lower elevated blood pressure in people with obesity and hypertension. That said, individual responses vary, and it's important to monitor your blood pressure regularly and discuss any changes with your GP or prescribing healthcare professional.
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.
How Does Mounjaro Affect Blood Pressure?
Mounjaro (tirzepatide) works as a dual GIP and GLP-1 receptor agonist that may help regulate blood sugar and support weight loss. In clinical trials, most participants experienced stable or improved blood pressure, particularly those with elevated baseline blood pressure. Weight loss itself often leads to improved blood pressure control — losing even 5–10% of body weight can have measurable cardiovascular benefits.
However, blood pressure changes depend on several factors: your baseline blood pressure, any existing medications (particularly blood pressure drugs), individual metabolism, and how your body responds to the tirzepatide dose titration. Some people report dizziness or lightheadedness early in treatment, which may relate to blood pressure fluctuations as your body adjusts.
- Most clinical trial participants saw stable or lower blood pressure
- Weight loss from Mounjaro may independently improve blood pressure
- Individual responses vary significantly
- Dose titration may affect cardiovascular stability initially
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.
What You Should Monitor and When to Seek Help
If you're taking Mounjaro via the KwikPen, it's wise to monitor your blood pressure regularly — ask your GP about home blood pressure monitoring or use a chemist blood pressure check service. Report any persistent dizziness, fainting, or chest discomfort to your prescriber immediately, as these may indicate a blood pressure issue requiring adjustment.
Blood pressure medications may need dose adjustment when starting Mounjaro — your prescriber should review all medications during your clinical assessment and at follow-up appointments. If you're already on antihypertensive drugs and you lose significant weight with Mounjaro, your blood pressure could drop lower than intended, sometimes requiring medication reduction. Always inform your GP of any blood pressure changes, and never adjust other medications without guidance.
- 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 directly lower blood pressure?
Mounjaro itself is not primarily a blood pressure medication. However, because it supports weight loss, and weight loss independently improves blood pressure, many people experience lower blood pressure as a side effect of losing weight. Clinical trials showed most participants had stable or improved blood pressure, not dangerous drops.
Can Mounjaro cause dangerously low blood pressure?
Dangerously low blood pressure (hypotension) is not a common side effect of tirzepatide in clinical trials. However, if you're also taking blood pressure-lowering medications and lose significant weight, your prescriber may need to adjust those medications to prevent blood pressure dropping too low.
What's the difference between Mounjaro and Wegovy regarding blood pressure?
Both Mounjaro (tirzepatide) and Wegovy (semaglutide) are GLP-1-based weight loss injections that may improve blood pressure through weight loss. Mounjaro is a dual GIP and GLP-1 agonist; Wegovy is GLP-1 only. Both showed stable or improved blood pressure in trials, not concerning drops.
Should I check my blood pressure while taking Mounjaro?
Yes, regular blood pressure monitoring is sensible, especially if you have a history of hypertension or take blood pressure medication. Ask your GP about home monitoring or use your local pharmacy's blood pressure service. Report any significant changes to your prescriber.
Can I use MyWeightCheck tools to track health changes on Mounjaro?
Yes. Use our free BMI calculator to monitor your weight status progress, and our GLP-1 weight loss calculator to estimate potential weight loss at different tirzepatide doses. Our progress tracker helps you log weight changes and any health improvements alongside your GP's clinical monitoring.
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.