Mounjaro is a popular weight loss medication in the UK, but like many prescription medications, you may experience side effects. In this article, we explore whether headaches are a side effect of Mounjaro, as well as information about other Mounjaro side effects – so read on for more.
What is Mounjaro?
Mounjaro is one of the UK’s leading weight loss drugs in 2025, with around 500,000 people currently taking the drug. The active ingredient in Mounjaro is tirzepatide – which works to reduce food cravings, increase feelings of fullness and lower blood sugars.
You inject the medication into your thigh, abdomen or upper arm once a week, gradually increasing the dosage as recommended by your doctor. Increasing the dosage slowly over time gives your body time to adjust to the medication; therefore, reducing the risk of side effects. But what are some side effects of Mounjaro? Let’s find out…
Mounjaro Side Effects
First of all, it’s important to note that Mounjaro side effects are completely normal, and are to be expected with all weight loss injections. They will ease off as your body adjusts to the medication. Some common side effects include:
- Stomach ache
- Feeling sick
- Vomiting
- Diarrhoea
- Constipation
Some people also experience heartburn, indigestion, bloating, sulphur burps and gas. Mounjaro is considered a safe and effective medication and is approved in the UK by regulatory agencies.
So, Will Mounjaro Give Me a Headache?
Some people may experience headaches when taking Mounjaro. However, this is not a common side effect – and there is no strong evidence to suggest Mounjaro directly causes headaches.
Instead, these headaches could be caused by other effects of Mounjaro, such as changes in blood pressure, dehydration, low blood sugar, nausea or dizziness.
So, headaches are not a commonly reported side effect of Mounjaro. In fact, a study published in the New England Journal of Medicine found that headaches were pretty much as common in patients taking tirzepatide as patients taking a placebo (around 6.5% - 6.8% of both groups experiencing headaches).
Are Mounjaro Headaches Serious?
Most Mounjaro headaches are not considered serious – they’re usually mild to moderate. However, in rare cases, headaches can be an indicator of something more sinister. Contact a medical professional if you experience:
- Double vision
- Blurred vision
- Numbness
- Weakness in arms or legs
- Pain in jaw
- Sore scalp
If you experience confusion, loss of vision, a high temperature, symptoms of meningitis or trouble speaking, call 999 immediately.
How to Manage Mounjaro Headaches
The good news is that if you are experiencing headaches whilst taking Mounjaro – or any other weight loss medication for that matter – there are some effective ways to manage them:
- Stay hydrated! Make sure you drink enough water throughout the day – 6 to 8 glasses or at least 2 litres is recommended.
- Eat regular, balanced meals – this will help you maintain stable blood sugar levels.
- Take over-the-counter painkillers such as paracetamol or ibuprofen.
- Relax in a dark, quiet room.
If your headaches are becoming troublesome, speak to us at Dr Frank’s Weight Loss Clinic to discuss reducing your Mounjaro dose or trying alternative weight loss medications. We can help you manage your side effects effectively and ensure you make the most of your medication.
Looking to Get Started on Mounjaro?
If you’re looking to try Mounjaro, you’re in the right place. At Dr Frank’s Weight Loss Clinic, you can make the most of Mounjaro prescriptions and expert support and advice from our registered weight loss nurses.
We’ll be with you every step of the way, giving you the best chance of success in Mounjaro. Start an assessment for Mounjaro with Dr Frank’s Weight Loss Clinic today to get started.
