Jump to: Why flu vaccination matters when taking Mounjaro | Understanding Mounjaro and vaccine interactions | When to take the medications | Managing side effects from both | Cold and flu remedies whilst on Mounjaro | Other vaccines and special considerations | Frequently asked questions | Take home message
You can safely have your flu jab while taking Mounjaro as there are no known interactions between tirzepatide (the drug in Mounjaro) and the flu vaccine1.
Whether you’re using Mounjaro for type 2 diabetes or weight loss, annual flu vaccination remains safe and is often recommended2.
The flu vaccine is an inactivated vaccine (not a live virus), making it safe to receive while on most medications, including Mounjaro1.
Healthcare professionals regularly administer flu vaccines to patients taking GLP-1 medications without any special precautions needed.
Important safety information: Mounjaro (tirzepatide) is a prescription-only medication for treating type 2 diabetes and managing obesity. This article is for informational purposes only. Always consult with your healthcare provider before starting any new medication, particularly if you have had your gallbladder removed or have other health conditions.
Why should you take the flu jab when on Mounjaro?
The NHS recommends flu vaccination for several groups, including people with diabetes and those with a BMI over 403.
Many people taking Mounjaro fall into these categories, making them eligible for free flu vaccination on the NHS.
Why the flu jab is recommended
Both type 2 diabetes and obesity can affect how well your immune system works.
High blood sugar levels can impair white blood cell function, making it harder to fight off infections.
Similarly, excess body fat produces inflammatory compounds that can disrupt normal immune responses.
This means people with these conditions often experience:
- More severe flu symptoms if infected
- Longer recovery times
- Higher risk of complications like pneumonia
Additionally, Mounjaro may actually help improve your immune function over time.
As the medication helps lower blood sugar levels and reduce body fat, it can decrease inflammation throughout the body.
Many people taking Mounjaro report feeling generally healthier as their metabolic health improves.
Getting the flu jab is particularly important when trying to lose weight or improve blood sugar levels.
Flu can disrupt your routine, affect your appetite in unpredictable ways, and potentially interfere with your Mounjaro schedule if you become severely unwell.
The flu vaccine helps protect you from serious illness that could derail your progress. It’s a simple step that takes just minutes but provides protection throughout the flu season (October to March in the UK).
Understanding Mounjaro and vaccine interactions
Mounjaro works by mimicking hormones, called GLP-1 and GIP, that manage blood sugar and hunger levels. It slows digestion and communicates directly with the brain to lower our desire to eat.
Vaccines work by training our immune system to recognise and fight specific viruses. The flu vaccine contains inactivated virus particles that can’t cause flu but help our body build immunity3.
Since Mounjaro doesn’t suppress our immune system, it won’t affect our body’s ability to respond to the vaccine.
The FDA prescribing information for Mounjaro lists no vaccine interactions1. Multiple healthcare professionals report administering flu vaccines to patients on Mounjaro without any additional concerns or special protocols.
When to take the medications
While there are no direct interactions between Mounjaro and the flu jab, a bit of planning around when to take the medications can reduce the impact of side effects:
Best time to get vaccinated:
- Any time you’re feeling well whilst on Mounjaro
- Earlier in the flu season (October-November) for best protection
- On a day when you can rest afterwards if needed
You might want to wait if:
- You’re experiencing severe Mounjaro side effects (wait until they settle)
- You’re severely nauseated or vomiting
- You have a fever or acute illness (standard vaccine guidance)
There’s no need to skip your Mounjaro dose when getting the flu jab. Continue taking your medication as prescribed unless your healthcare provider advises otherwise1.
Managing side effects from both
It’s helpful to know what to expect so you can distinguish between normal vaccine reactions and Mounjaro side effects:
Common flu jab reactions:
- Sore arm at injection site (very common)
- Mild tiredness or headache (1-2 days)
- Slight temperature or aching (less common)
How these differ from Mounjaro side effects:
- Flu jab reactions are typically short-lived (24-48 hours)
- Arm soreness is specific to the vaccine, not a Mounjaro effect
- Any nausea is more likely from Mounjaro than the vaccine
Tips for comfort:
- Take paracetamol for arm soreness or mild fever
- Rest and stay hydrated
- Apply a cool compress to the injection site
- Continue your normal Mounjaro routine
Cold and flu tips while on Mounjaro
If you do catch a cold or flu despite vaccination, most over-the-counter medicines are safe with Mounjaro1:
Safe options:
- Paracetamol for fever and aches
- Throat lozenges and warm drinks
- Rest and plenty of fluids
- Simple cough mixtures
- Continue to eat a diet based on whole foods and minimise ultra-processed foods
Use with caution:
- Decongestants (can affect blood pressure)
- Ibuprofen (may irritate stomach, especially with Mounjaro’s digestive effects)
- Medicines containing sugar (check labels if managing diabetes)
Always check with your pharmacist when buying cold and flu medicines. They can advise on the best options considering your Mounjaro prescription.
Other vaccines and special considerations
The same safety profile applies to other common vaccines:
Also safe with Mounjaro:
- COVID-19 vaccines and boosters
- Shingles vaccine (for those eligible)
- Pneumonia vaccine
- Most travel vaccines
Special considerations:
- Live vaccines (like yellow fever) – discuss timing with travel clinic
- If you’re immunosuppressed for any reason, discuss with your GP
- Keep a record of all vaccinations in case of side effects
Always tell the healthcare professional giving any vaccine that you’re taking Mounjaro, though in most cases it won’t change their approach.
Frequently asked questions
Should I skip my Mounjaro dose when getting the flu jab?
No, continue taking Mounjaro as prescribed. There’s no need to adjust your medication schedule for the flu vaccine.
Can I have other vaccines whilst on Mounjaro?
Yes, most vaccines are safe with Mounjaro, including COVID-19 boosters and routine vaccinations. Always inform the healthcare provider about your medications.
What if I feel unwell after the flu jab?
Mild tiredness or arm soreness is normal. If you develop severe symptoms or feel very unwell, contact your GP or call 111 for advice.
Can I take paracetamol for vaccine side effects?
Yes, paracetamol is safe to take with Mounjaro and can help with any discomfort from the flu jab.
Where can I get my free flu jab?
If eligible, you can get your free flu jab at your GP surgery, participating pharmacies, or some supermarket pharmacies. Check the NHS website for locations.
Should I tell the nurse I’m on Mounjaro?
Yes, always mention all medications you’re taking. While it won’t affect the flu vaccine, it’s important for your medical records.
Can Mounjaro affect vaccine effectiveness?
No, Mounjaro doesn’t suppress your immune system or reduce vaccine effectiveness. Your body will respond normally to the vaccine.
What about COVID-19 boosters?
COVID-19 vaccines are safe with Mounjaro. You can have your flu jab and COVID booster at the same appointment if offered.
Take home message
Taking Mounjaro doesn’t prevent you from having your flu jab – in fact, protecting yourself from flu is especially important whilst focusing on your health goals.
The vaccine won’t interfere with how Mounjaro works, and Mounjaro won’t stop the vaccine from protecting you.
Book your flu jab as you normally would, continue taking Mounjaro as prescribed, and don’t worry about interactions between the two.
If you’re eligible for a free NHS flu vaccine, take advantage of this protection. Your pharmacist or practice nurse can answer any specific concerns when you attend for your vaccination.
Remember that preventing flu is much easier than treating it, especially when you’re working on managing your weight or diabetes with Mounjaro.
Second Nature's Mounjaro and Wegovy programmes
Second Nature provides Mounjaro or Wegovy as part of our Mounjaro and Wegovy weight-loss programmes.
Why choose Second Nature over other medication providers, assuming you're eligible?
Because peace of mind matters.
We've had the privilege of working with the NHS for over eight years, helping people across the UK take meaningful steps toward a healthier, happier life.
Our programmes are designed to meet people where they are, whether that means support with weight loss through compassionate one-to-one health coaching, or access to the latest weight-loss medications (like Mounjaro and Wegovy) delivered alongside expert care from a multidisciplinary team of doctors, psychologists, dietitians, and personal trainers.
At the heart of everything we do is a simple belief: real, lasting change comes from building better habits, not relying on quick fixes. We're here to support that change every step of the way.
With over a decade of experience, thousands of lives changed, and a long-standing record of delivering programmes used by the NHS, we believe we're the UK's most trusted weight-loss programme.
We hope to offer you something invaluable: peace of mind, and the support you need to take that first step.
References
- Food and Drug Administration. (2022). Mounjaro (tirzepatide) injection prescribing information
- National Institute for Health and Care Excellence. (2024). Tirzepatide for managing overweight and obesity (TA1026)
- GOV.UK. (2025). The flu vaccination: who should have it and why (winter 2025 to 2026)
- National Institute for Health and Care Excellence. (2023). Tirzepatide for treating type 2 diabetes (TA924)
