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 Pregabalin: Safety And Interactions
If you're taking pregabalin (Lyrica) and considering Mounjaro (tirzepatide) for weight management, it's important to understand how these medications may interact. Pregabalin is commonly prescribed for nerve pain, anxiety, and seizures, whilst Mounjaro is a prescription-only GLP-1 and GIP receptor agonist for weight management in UK adults. There is no known major direct interaction between these two medications, but your GP or prescriber must assess your individual situation before starting Mounjaro. Always disclose all medications you're taking during your clinical assessment.
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 Mounjaro And Pregabalin Work Differently
Pregabalin is a gabapentinoid that works on nerve signals to reduce pain and anxiety. It does not directly affect appetite or weight regulation. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist that mimics natural hormones to reduce appetite, slow gastric emptying, and support weight loss. These are completely different drug classes with different mechanisms, which is why there is no documented major interaction between them.
However, both medications can cause side effects that may overlap or compound. Pregabalin commonly causes dizziness, fatigue, and drowsiness. Mounjaro commonly causes nausea, diarrhoea, and stomach discomfort. Taking both together might increase feelings of tiredness or digestive symptoms, so your prescriber needs to know about the pregabalin before initiating Mounjaro. Your GP can assess whether the combination is safe for your specific health situation.
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.
Assessment And Prescriber Guidance
Before starting Mounjaro, always inform your GP or the prescriber conducting your clinical assessment that you take pregabalin. Include the dose, how long you've been taking it, and why it was prescribed. Your prescriber will review your full medication list and health history to confirm Mounjaro is appropriate for you. If you're prescribed Mounjaro whilst on pregabalin, you may be monitored more closely for side effects, particularly dizziness or gastrointestinal symptoms. Never stop pregabalin without your GP's approval, and report any new or worsening symptoms once you start Mounjaro. Use our free GLP-1 weight loss calculator to explore potential outcomes, and discuss results with your prescriber.
- 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.
Is it safe to take Mounjaro and pregabalin together?
There is no known major direct interaction between Mounjaro and pregabalin. However, both can cause dizziness and fatigue, so effects may compound. Your prescriber must assess your individual health before prescribing Mounjaro. Always disclose pregabalin use during your clinical assessment.
Will pregabalin reduce Mounjaro's effectiveness?
Pregabalin does not directly interfere with how Mounjaro works. Mounjaro's weight management effects depend on appetite reduction and dietary adherence, which pregabalin does not block. However, individual response varies, and your prescriber will assess suitability.
What side effects might combining these medications cause?
Pregabalin commonly causes dizziness and drowsiness; Mounjaro often causes nausea and diarrhoea. Combined, you may experience increased fatigue or stomach symptoms. Report any significant changes to your GP promptly.
Can I switch from Mounjaro to Wegovy if I'm taking pregabalin?
Both Mounjaro and Wegovy have no known major interaction with pregabalin. Switching would be based on clinical suitability, not the pregabalin. Your prescriber will advise which is appropriate for you.
What should I tell my prescriber about pregabalin?
Tell your prescriber the exact dose, how long you've taken it, and the reason (nerve pain, anxiety, seizures, etc.). Include all other medications too. This helps them assess whether Mounjaro is safe and right for you.
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.