Experiencing headaches on Mounjaro? Here's why

For many people with weight-related health issues, Mounjaro has been a real lifesaver. But that’s not to say it’s always a walk in the park.

Like most medications, starting Mounjaro can come with some less-than-ideal side effects. From a rumbling tummy to a painful head, there are a few struggles you might experience as your body adjusts to the medication.

Some side effects are more common than others, and all of them should be reported to your healthcare provider.

When it comes to Mounjaro headaches, we've answered all your pressing questions, including:

• Why do patients taking Mounjaro get headaches?
• How do you prevent them?
• And when should you seek medical attention?

Are headaches a common side effect of Mounjaro?

The short answer is no. Headaches are not one of the most common side effects for people taking Mounjaro. But that doesn’t mean your experience is any less real or valid.

One research review looked at 3 studies with over 4,000 patients to identify common side effects. It found that less than 10% of people taking Mounjaro experienced headaches [7].

A separate review of 10 clinical trials found that higher doses carried increased risk of headaches, but it was still 10% or less of all participants in the trials [6].

We know it can be a painful wait, but we also wanted to remind you that most side effects do fade over time.

A study of adverse events reported in the US over 2 years found that all side effects of Mounjaro were most likely during the first month of use, and their frequency decreased over time [11].

It’s also good to remember that up to 80% of people taking Mounjaro will experience at least 1 side effect [3].

That’s not to say you have to put up with side effects. But, it is important to speak with your healthcare provider about them and try to wait until your body adjusts to the medication.

What are the most common side effects of Mounjaro?

You might be wondering which side effects are most likely. It’s a good question, and one we’ll be happy to answer for you.

Multiple studies have found that the most common side effects of Mounjaro happen in the digestive system. These include [1][2]:

• Nausea
• Diarrhoea
• Constipation
• Vomiting

We explain more about the medication, how it works and problems to watch out for in our guide to Mounjaro.

Do all weight loss injections cause headaches?

When it comes to different weight loss treatments, you’re not likely to find one with zero issues. But that’s partly because every medication has the potential for side effects. They’re usually minor and they don’t last forever [4].

According to the NHS, there are 3 weight loss medications currently available in the UK [5]:

• Mounjaro (tirzepatide)
• Ozempic or Wegovy (semaglutide)
• Saxenda (liraglutide)

All of these have similar side effects, including gut issues, headaches, fatigue and hypoglycaemia (low blood sugar).

One of the reasons Mounjaro is often prescribed is that, so far, research shows it is the most effective weight loss treatment. It helps more people achieve significant weight loss than the other options with a similar amount of side effects [7].

It’s important to remember that everyone’s body responds differently to medication. While your body might not tolerate Mounjaro well, another person may have limited side effects.

So, you should be working with your doctor to find the medication that has the least side effects for you.

Why does Mounjaro cause headaches?

If you fall within the 10% of people who do get headaches while taking Mounjaro, you’re probably wondering why. There are a few possible answers to this one.  Here are 4 of the most likely:

Dehydration

Earlier, we mentioned that the majority of Mounjaro users will experience gut issues. These might include vomiting and diarrhoea, which also happen to be major causes of dehydration [4].

It’s the start of a not-so-fun cycle, where side effects of Mounjaro (gut issues) lead to a separate health problem (dehydration) and then, another side effect (headaches).

It’s important to drink plenty of fluids while taking Mounjaro and keep an eye out for signs of dehydration. Symptoms to watch out for include:

• Dry mouth
• Dark urine
• Dizziness
• Headaches
• Muscle weakness

Low blood sugar (Hypoglycaemia)

Mounjaro, with the active ingredient tirzepatide, is a medication that works by activating the GIP and GLP-1 receptors in the body. One of its key actions is reducing blood sugars [5].

This can lead to hypoglycaemia, or low blood sugar [8]. Hypoglycaemia is most common for people with diabetes, but it can happen to generally healthy people taking Mounjaro too.

Surprise, surprise; one of the key side effects of low blood sugar is headaches. It’s estimated that around 10-20% of people without diabetes on GLP-1 medications could experience hypoglycaemia and headaches [8].

Even without hypoglycaemia, general fluctuations in blood sugar levels can cause spasms in the arteries in your head, which lead to a headache [10].

It’s best to speak with your doctor about blood sugar levels, as they’re the only ones who can diagnose hypoglycaemia. They can also offer some prevention and treatment strategies.

Overstimulated GLP-1 receptors

We mentioned earlier that Mounjaro is a GLP-1 medication, which means it works by interacting with receptors in your body. Some of these receptors are found in the lower parts of your brain.

The medication may be overstimulating these receptors, which is leading to painful side effects like headaches [8].

This is just a theory for now, with further research needed to back it up. However, it does make sense when you consider that headaches become more likely on higher doses of the medication [6].

Other medication interactions

It’s a well-known fact that mixing medications can lead to negative side effects, which is why it’s important to tell your healthcare provider about any medicines you’re taking. They need the full picture to ensure that what they recommend to you will be safe and effective.

This includes all prescribed medicines, supplements and vitamins – even those available over-the-counter or at the supermarket.

For example, some diabetes medications are known for not playing well with Mounjaro. Medications like insulin or sulfonylurea can lead to hypoglycaemia when taken alongside Mounjaro. Which, you guessed it, is a common issue for headaches [4].

Ongoing support to help you manage Mounjaro side effects

When it comes to your health, you shouldn't have to figure it all out alone.

Juniper's Weight Loss Reset Programme combines weight loss medication with dietitian-led health coaching and tracking, so you can lose weight and reach your goals for good.

Kickstart your weight loss journey with Wegovy or Mounjaro, two groundbreaking weight loss medications that mimic the GLP-1 and GIP hormones, respectively, to help control cravings, delay stomach emptying, and keep you feeling fuller for longer. These clinically backed treatments help members experience up to 20% body weight loss.

Plus, we have a team of expert dietitians and health coaches you can consult with to help you work through any challenges you're experiencing during your weight management journey. This approach sets you up for sustained weight loss, rather than a quick-fix solution.

This means you can continue to enjoy the things you love in moderation without ever feeling deprived.

Ready to see if Juniper is right for you? You can check your eligibility here.

How to prevent headaches while taking Mounjaro

If headaches are becoming a serious pain in your…head, then you probably want to know how to get rid of them.

It depends on what the cause is, so a check-in with your doctor is our best recommendation. But, there are also a few general diet and lifestyle changes you can try.

Review your diet

We don’t have to tell you twice that a healthy diet is a key part of success when you’re on Mounjaro. When it comes to headaches, there are also a few diet tips to keep in mind.

First, you’ll want to focus on plenty of protein, which is known to help control blood sugar and can protect against low blood sugar [8].

Second, you need to make sure to drink plenty of water; that's 8 glasses (or more) each day. This will help prevent dehydration, which is one possible cause of headaches on Mounjaro. 

Next, you can do a bit of a diet audit to check for any trigger foods. It can help to keep a food diary to keep track of when eating a certain food leads to a headache soon after [12].

Common trigger food and drinks include [9]:

• Aged cheeses
• Alcohol
• Caffeine
• Salted nuts

Then there are additives, like MSG, which is commonly found in foods and often leads to headaches. Another one to be aware of is aspartame – the artificial sweetener used in diet drinks and sugar-free gum.

Finally, you can ask a health professional to check on any vitamin or mineral deficiencies that could be causing your headaches.

In a case study of a 43-year-old woman experiencing migraines on Mounjaro, a nutritionist was able to reduce her side effects through a high-protein diet and a range of supplements [8].

Eat frequent meals

Did you know that eating regular meals helps stabilise blood sugars? Regular will look different for most people, but in general, it’s up to 4 meals per day, spaced 3 hours apart [8].

Keeping your blood sugar levels stable is key for avoiding hypoglycaemia and the headaches that come with it.

Fasting is also recognised as a trigger for headaches and low blood sugar. So, even though you’re on a weight loss journey, it’s important that you’re eating frequent meals and getting enough calories to support your body throughout the day.

Prioritise quality sleep

There’s nothing groundbreaking about a regular sleep routine, but it does bear repeating. Getting 7-9 hours of quality shut-eye is a good way to protect your health, including helping avoid headaches.

That’s because both too much and too little sleep have been linked to headaches, as a trigger and making symptoms worse [9].

Ask about a lower dose

If you’ve tried everything under the sun and you’re still getting regular headaches, your prescribing doctor might consider changing your Mounjaro dose.

Multiple studies have found that side effects of all kinds are more common with higher doses of the drug [6]. They’re also more likely to occur during Mounjaro dosage escalation, or when you’re increasing the medication [1].

This is one reason you start on the lowest minimum dose and increase gradually. Sometimes, you might be recommended to skip a dose of your medication or drop back to a lower dose for a short time [3].

This method has proven effective for managing gut side effects, so it may be useful when it comes to preventing headaches as well.

It’s important that you only adjust your medication on the advice of your doctor. It’s not safe to make any changes without expert advice from a qualified health professional. 

Managing Mounjaro headaches when they occur

You’ll be pleased to know that managing Mounjaro headaches is pretty similar to managing any other type of headache – you need rest, water and perhaps a few painkillers. 

Relief methods and treatment options

Over-the-counter pain medications like aspirin, ibuprofen and paracetamol are effective at treating headaches [9][10]. So, they’d be the first place to start.

Other ways to relieve a headache include [12]:

• Lie down in a quiet and dark room
• Use an ice pack or a warm cloth on the back of your neck or forehead
• Go for a walk in the fresh air
• Drink plenty of water
• Try stretching your neck muscles

If your doctor has diagnosed you with hypoglycaemia, then you might find a sugary snack helps relieve a headache. Popular options include jelly beans or a glass of orange juice. Another option might be glucose tablets [4].

Long-term treatment plans

For headaches that keep coming back, it’s a good idea to chat with your doctor about long-term relief strategies and treatment options.

There are stronger medicines that a doctor can prescribe for certain types of headaches. For example, some antidepressants are also effective for migraines and tension headaches [9]. 

Alternative therapies such as acupuncture and chiropractic have also been used for headache treatment. Another option is relaxation and stress relief techniques, like meditation or massage [9][10].

Taking care of your overall health is another good way to keep headaches at bay. It’s all the things you already know – like eating a balanced diet, exercising regularly, staying hydrated and getting quality sleep [12]. 

When to seek medical advice for side effects

It’s important that you report all side effects (even minor ones) to your doctor, pharmacist or nurse [2]. They can help you manage common side effects and advise on whether the medication is right for you.

It’s extra important when it’s a new medication, like Mounjaro. That’s because healthcare providers and the UK government are continuing to monitor their safety in the general population [5].

You can also report side effects to the Yellow Card Scheme, which is run by the MHRA – the UK’s medicine safety watchdog.

Serious side effects of Mounjaro

Some side effects require immediate medical attention, either from your doctor or emergency healthcare.

According to the Mounjaro KwikPen patient information leaflet, serious side effects include:

• Acute pancreatitis: severe stomach pain and/or back pain combined with vomiting and/or diarrhoea
• Allergic reactions: symptoms include a rash, hives, itching and swelling of the neck, face, mouth or throat, breathing issues or difficulty swallowing
• Gallbladder issues: sudden severe pain in the upper stomach, a fever and/or yellow skin 

If you experience any of these symptoms, it's considered a medical emergency, and you should seek support ASAP.

If you’re worried about general Mounjaro side effects at any time, make sure to check in with your doctor.

‍

Image credit: Pexels