Mounjaro Side Effects and How to Manage Them

Every medication can cause side effects, and Mounjaro’s no different.

So if you’re considering weight management treatment with Mounjaro, you’re probably wondering what side effects you could experience, and how to manage them.

Here, our experts break them down for you. We’ve also included tips on how to relieve discomfort and make your treatment as safe and simple as possible.

Mounjaro side effects: summary

• You’re most likely to experience side effects from Mounjaro when you first start treatment, or increase the strength of your dose. In many cases the side effects are mild, can be managed at home and ease off as your body adjusts to the medication.
• The most common side effects of Mounjaro for weight management are digestive (like nausea, vomiting, diarrhoea and constipation). However, it’s important to be aware of the uncommon side effects of Mounjaro, too.
• If you're experiencing particularly intense side effects, or side effects that aren't easing, speak to your healthcare provider. If you begin to experience severe side effects, seek immediate medical attention.

How Mounjaro works: why do we get side effects?

Mounjaro is a weight loss injection which contains the active ingredient tirzepatide. It works by mimicking two hormones naturally released by your digestive system, GIP and GLP-1. It’s used to help with weight loss because it reduces hunger and food-related thoughts, and also slows your digestion. This may help you to feel full between meals. [1] However, it may also cause certain side effects: we’ll explore those in this article. [1]

Is Mounjaro safe?

“Mounjaro has been officially approved by the MHRA (Medicines and Healthcare products Regulatory Agency) for weight management treatment since 2023. [2] For many people, it’s an effective way to support weight loss and weight management, when used alongside positive lifestyle changes like a healthy diet and increased movement.

“However, it’s really important that you purchase Mounjaro from a reputable source. Because Mounjaro is a prescription-only medication, it should only be provided by, and taken under the supervision of, a licensed healthcare professional. This should include an initial assessment to check your eligibility, as well as regular check-ins to monitor your progress and make sure that Mounjaro is still the right treatment for you.”

- Dr. Sophie Dix, Head of Medical Affairs, MedExpress

Risks of taking Mounjaro

Like any medication, there’s a chance you may experience side effects while taking Mounjaro. For most people, these are mild to moderate and most often occur when you’re new to treatment or are increasing your dose. Most of them can also be managed from the comfort of home. However, there is also a risk of rarer, but more serious, side effects. We’ll explain what those are later in this guide.

Mounjaro side effects

Summary of Mounjaro side effects

Very common side effects

Very common side effects may affect more than 1 in 10 people. They include:

Feeling sick (nausea)

What is it?

When you feel sick (nauseous) you may feel queasy, like you want to vomit. It may also feel like your stomach is churning.

Why does this happen?

Because Mounjaro slows digestion, any food you eat stays in your stomach for longer and may cause your stomach to expand. This may make you feel nauseous.

In most cases, any nausea you experience is usually not severe. You're most likely to experience it at the beginning of treatment, and it should ease after a short period of time. [1]

Here's what we recommend to manage feeling sick:

• Eat smaller meals, more frequently
• Drink plenty of water. Mint and ginger-based drinks may also reduce nausea.
• Avoid foods high in sugar and fat
• Get plenty of fresh air
• Avoid strong smells, where possible [3]

Diarrhoea

What is it?

Diarrhoea is when you experience loose or watery poos, more than three times in one day. [4] You may also feel stomach discomfort or cramps.

Why does this happen?

Because Mounjaro slows how quickly food and drink leave the stomach, it may disrupt normal digestion. In some people, this may result in diarrhoea. [5]

Here's what we recommend to manage diarrhoea:

• Stay hydrated by drinking plenty of water (aim for small, frequent sips)
• Eat small, frequent meals
• If you can, try to rest as much as possible [3]

Diarrhoea is usually not a severe side effect of Mounjaro, and it’s most common when you first start treatment. It should decrease over time. [1]

Contact your GP or call 111 if:

• Diarrhoea lasts for more than a week
• Your poo contains blood
• You have signs of dehydration (dark urine, peeing less than usual)
• You're using oral contraception and have experienced diarrhoea that has lasted for over 24 hours, as you may need a repeat dose of your pill to avoid an unwanted pregnancy

Important: Call 999 or go to A&E if:

• You have sudden or severe stomach pain
• You're experiencing a high fever or chills

Vomiting

What is it?

Vomiting is when the contents of your stomach are forcefully ejected through your mouth. It usually happens after you've already been feeling nauseous.

Why does this happen?

Just like with nausea and diarrhoea, vomiting sometimes occurs during Mounjaro treatment because of the way the medication slows digestion. These changes may result in vomiting, particularly when you first start treatment or increase your dose. However, in most cases it's usually not severe, or long-term. [1]

Here's what we recommend to manage vomiting

• Take small, frequent sips of water to stay hydrated. Ginger and mint-based drinks may also help
• Eat smaller, bland meals (like plain toast or a banana) to support your energy levels [3]

Contact your GP or call 111 if:

• You’ve been vomiting for more than a couple of days
• You have signs of dehydration (dark urine, or peeing less than usual)
• You're using oral contraception and have experienced diarrhoea that has lasted for over 24 hours, as you may need a repeat dose of your pill to avoid an unwanted pregnancy

Important: Call 999 or go to A&E if:

• Your vomit contains something that looks like coffee granules
• Your vomit contains blood
• You have a fever alongside your vomiting
• You have sudden or severe stomach pain alongside your vomiting
• You’re vomiting 3 times or more a day

Stomach pain

What is it?

Stomach pain occurs when you feel discomfort or aching anywhere in your stomach (abdomen). This could include trapped wind, which usually feels like bloating or pressure in your stomach, or stomach cramps.

There are different types of stomach pain which could also be connected to another side effect, like diarrhoea or constipation.

Why does this happen?

Like many of the common Mounjaro side effects, stomach pain is often linked to how Mounjaro slows digestion. This slower pace of stomach emptying may trigger bloating.

Here's what we recommend to manage stomach pain:

• Avoid spicy or greasy foods
• If you're experiencing cramps, try holding a heat pack to your stomach
• Chew your food slowly [3]

If your stomach pain becomes severe, we recommend you follow the advice below.

Important: Call 999 or go to A&E:

If your stomach pain becomes severe. Severe means:

• It’s so intense that you can’t focus on anything else
• It makes it nearly impossible to handle normal daily tasks (like walking, getting dressed, or eating)
• It doesn’t improve with over-the-counter pain relief or rest
• It radiates to your back or underneath your right ribcage or your right shoulder
• You also have severe vomiting (3 or more times in a day)

Constipation

What is it?

Constipation is when you find it difficult to pass poos (which may cause discomfort), and you have fewer than 3 bowel movements in a week. [6] Your poos may also be hard and dry.

Why does this happen?

Because Mounjaro affects the way your digestive system works, constipation is a very common side effect of treatment.

Here's what we recommend to manage constipation:

• Stay hydrated by drinking plenty of water
• Eat high-fibre foods, like wholewheat pasta and chickpeas
• Increase your daily movement, because exercise can stimulate bowel movements [3]
• If it's appropriate for you, glucomannan supplements may help to regulate your bowel movements and soften poos. This makes them easier to pass. [7]

Contact your GP if:

• Your constipation does not improve even after following the advice above
• You notice blood in your poo

Common side effects

Common side effects may affect up to 1 in 10 people. They could include:

Feeling tired (fatigue)

What is it?

Fatigue is when you frequently feel overwhelmingly tired, even after rest. When you have fatigue, you may find it more difficult to complete everyday tasks.

It's reported as a common side effect in those taking Mounjaro for weight management. [1]

Why does this happen?

There is no evidence to suggest that Mounjaro itself affects energy levels. However, if you're not feeling hungry or craving certain foods as often, you may be eating less than before. [8] There is some evidence to suggest that fluctuations in your blood sugar levels could make you feel more tired. [9]

Here's what we recommend to manage fatigue:

• Fatigue often means your body needs more nourishment. We advise you:
  • Eat enough nutrient-dense food to sustain your energy levels. This means getting enough protein and complex carbohydrates, as well as eating plenty of fresh fruits and vegetables.
  • Make sure you're getting enough vitamins. For example:
    • Vitamin B12 supports energy production. [10] You can find it in dairy products, meat and eggs.
    • Low vitamin D levels are also linked to fatigue. [11] While sunlight is the best source of this vitamin (be sure to wear SPF 30+ sunscreen every day), egg yolks and oily fish are also a good food source. [12, 13]
    • Low iron levels can also cause fatigue. [14] Red meat, beans and leafy greens are all ideal food sources, but if you suspect you have an iron deficiency you should speak to your doctor. They may be able to refer you for tests to check your iron levels.
• Aim for daily movement. Regular exercise can support energy levels. [15]
• Aim for 7 to 9 hours of sleep a night, maintaining a regular sleep schedule and avoiding screens for the final hour before bed. [16]

Allergic reaction (hypersensitivity)

What is it?

Hypersensitivity is when your body reacts to one of the ingredients in Mounjaro.

It's really important to differentiate between a milder reaction and a severe reaction (more on that below). This section focuses on mild reactions like a rash, itching and eczema.

Why does this happen?

If you’re allergic to any of the ingredients in Mounjaro, your body may trigger an allergic immune response. These are the mild reactions like those we have described above. [1] Be sure to read the full list of ingredients in your Patient Information Leaflet (PIL) before taking any medication, and make your healthcare provider aware of any existing allergies that you have during your initial consultation.

Here's what we recommend to manage hypersensitivity:

If your reaction is mild, you may be able to treat it at home. For example, a cold compress may relieve skin irritation. However, we'd still recommend you speak to your doctor, and keep a close eye on your symptoms. If you have any concerns, call 111 for further assistance.

You can also report reactions via the MHRA Yellow Card Scheme, to help raise awareness of potential side effects.

Important: Call 999 or go to A&E if:

If you experience difficulty breathing, or swelling of the lips, tongue, or throat. These could be signs of a severe allergic reaction (also called anaphylaxis), which can be life-threatening.

Dizziness

What is it?

If you're experiencing dizziness, you may feel lightheaded, faint and unsteady. It may also feel like your surroundings are spinning (vertigo).

Why does this happen?

Because Mounjaro affects your blood sugar levels, you may feel dizzy on occasion, particularly when you're first starting treatment or when you increase your dose. You're also more likely to feel dizzy if you're dehydrated. [17]

Here's what we recommend to manage dizziness:

• Drink plenty of fluids to avoid dehydration
• When you're feeling dizzy, move carefully and slowly to avoid injury. If possible, slow down until your dizziness passes.
• Avoid coffee, cigarettes and alcohol. Caffeine and nicotine may affect your heart and circulation, and alcohol could affect your hydration levels. [18, 19]

Contact your GP or call 111 if:

• You’re having trouble hearing or speaking
• You’re hearing ringing in your ears
• You experience vision changes
• You lose consciousness or faint

Important: Call 999 or go to A&E if:

• You experience dizziness and your face, arms or legs feel numb or weaker than usual

Low blood pressure (hypotension)

What is it?

Low blood pressure (hypotension) is where the blood pressure in your arteries is too low. Low blood pressure has been observed in people taking Mounjaro for weight management. [1, 20]

If you experience low blood pressure, you may feel dizzy and lightheaded. [21]

Why does this happen?

Low blood pressure is believed to be an indirect side effect of taking Mounjaro. It could happen because of rapid weight loss, or possibly linked to dehydration caused by other side effects. [22]

Here's what we recommend to manage low blood pressure:

• Speak to your doctor. They may be able to provide additional support and monitoring.
• Drink plenty of fluids, to avoid dehydration
• Avoid alcohol, as it may make you more dehydrated [19]
• If you can, rest. If you’re feeling dizzy, avoid moving too quickly and try to lie down until the dizziness passes.

Indigestion (dyspepsia)

What is it?

Indigestion is a feeling of discomfort or pain in your stomach, which usually happens after eating.

Why does this happen?

Because Mounjaro slows your digestion, you’re likely to feel more full. [1] However this also means that if you eat too quickly, or eat a larger meal, you may experience indigestion.

Here's what we recommend to manage indigestion:

• Eat smaller, more frequent meals
• Chew slowly, setting your fork down between bites
• Avoid eating too close to bedtime
• Drink plenty of water to support digestion

Stomach bloating, burping or flatulence

What is it?

When you first take Mounjaro, or increase your dose, you may notice you feel bloated, or burp and pass gas more frequently.

Why does this happen?

Because Mounjaro slows down how quickly food leaves your stomach, food may stay in your stomach for longer. As a result, gas can build up during digestion. This may cause bloating, which may also be released through burping or passing gas.

Here's what we recommend to manage bloating:

• Avoid fizzy drinks and chewing gum, as these may make bloating feel more uncomfortable
• Eat and drink slowly, to help reduce the amount of air you swallow
• Take regular walks, to support digestion and reduce bloating

Acid reflux or heartburn (also called gastroesophageal reflux disease or GORD)

What is it?

Heartburn is when you feel a burning sensation in the chest or throat. You may also experience a sour taste in your mouth. It’s caused by stomach acid travelling up your food pipe and into your throat. [23] If it happens frequently, we would recommend that you speak to your doctor as you may have a common condition called gastroesophageal reflux disease (GORD).

Why does this happen?

Because food stays in your stomach for longer while you’re taking Mounjaro, the chance of experiencing acid reflux increases. [5]

Here's what we recommend to manage acid reflux or heartburn:

• Avoid rich, spicy or fatty foods
• Reduce your caffeine intake
• Don’t eat too close to bedtime (aim to finish your last meal around 3 hours before bed) [24]
• If you experience heartburn or reflux frequently, consider taking an over-the-counter heartburn medication to ease discomfort

Hair loss

What is it?

Hair loss typically happens when the normal cycle of growth is disrupted. This is often due to a specific type of hair loss called telogen effluvium (TE), which causes excess shedding all over the scalp. You may notice more hair loss than usual when brushing or washing your hair.

Why does this happen?

Hair loss has been observed in patients taking weight loss medication. [1] This could be because sudden, rapid weight loss may trigger TE. [25, 26] It sometimes happens when your body interprets your weight loss as a form of stress. And, when your body’s stressed, it may temporarily pause the production of things that aren’t critical, like hair growth. [27]

Here's what we recommend to manage hair loss:

The good news is that this type of hair loss is usually temporary, and your hair should grow back once your body adjusts to treatment. In the meantime:

• Eat a balanced diet which meets the recommended daily intake (RDI) of protein, iron, zinc and B vitamins. These nutrients have been shown to support hair growth. [28, 29]
• Try to manage any stress you may be experiencing as much as possible, as high stress levels can affect hair growth. [30] Mindfulness and breathing exercises may help.
• Aim for gradual, steady and sustainable weight loss. Anywhere between 0.5kg-1kg per week is ideal, to reduce any potential stress on your body. [31]

Injection site reactions

What is it?

It’s normal to notice a small dot of blood, a temporary raised lump or mild bruising after your injection. However, some people may notice a localised skin response to the Mounjaro injection, which occurs around the injection site.

You’ll often notice symptoms within the first 24-48 hours. These include:

• Pain
• Redness
• Swelling
• Warmth
• Itching
• Bruising
• Tenderness

Why does this happen?

If you experience an injection site reaction, your body may be responding either to the injection itself, or how it was administered. Make sure you correctly follow the injection instructions each time you take your treatment.

Here's what we recommend to manage injection site reactions:

• You can inject in the same area each week, but not in the exact same spot
• Reading (or watching) the instructions each time you take your medication may help to reduce the risk of administering it incorrectly

Contact your GP or call 111 if:

• You notice intense redness around the injection site
• You notice a rash that worsens or spreads around the injection site
• You notice warmth or pus at the injection site
• You also have a fever or chills

Important: Call 999 or go to A&E if:

If you experience difficulty breathing, or swelling of the lips, tongue, or throat. These could be signs of a severe allergic reaction (also called anaphylaxis), which can be life-threatening.

Gallstones

What is it?

Gallstones are small stones, formed from hardened deposits of bile and cholesterol in the gallbladder. Most of the time, gallstones don’t cause any symptoms, and you may not realise you have them. However, in severe cases they can cause intense pain. If you experience severe abdominal pain while taking Mounjaro, you should call 111 for urgent advice and support.

Why does this happen?

During treatment, you may experience rapid fat loss. When you lose a lot of fat quickly, your liver may release extra cholesterol to help your body digest the fat. If you have too much cholesterol, you’re more at risk of developing gallstones. [32] Taking Mounjaro may also increase your risk of other gallbladder related issues, like cholecystitis (gallbladder infection). [5]

Here's what we recommend to manage gallstones:

If you think you have gallstones, seek immediate medical attention. Call 999 or go to A&E if:

• You have severe pain under your right ribcage that extends to your right shoulder or back that disrupts your normal daily activities (possible acute gallbladder disease)
• The pain is accompanied by vomiting and/or a high temperature
• You have a rapid heartbeat

Uncommon side effects

Uncommon side effects may affect up to 1 in 100 people. They include:

Changed sense of taste (dysguesia)

What is it?

Some people may find that taking Mounjaro affects the way their food tastes. [33] This isn’t a serious side effect, but it may affect your relationship with certain foods. Symptoms include:

• A lingering bad taste in the mouth, even without eating
• Foods that you once enjoyed now taste unpleasant
• Sweet or salty foods might not taste the same
• Foods might taste bitter (even if they’re not) or metallic

Why does this happen?

Mounjaro works to influence our brains’ “reward system”. This means that foods we once enjoyed, particularly “high-reward” salty and sweet flavours, might not taste the same anymore. [33]

Here's what we recommend to manage change in taste:

• Avoid smoking, as this may also affect your sense of taste
• Drink plenty of water to wash away food particles and bacteria
• Brush and floss your teeth regularly

Change in skin sensation (dysesthesia)

What is it?

When taking Mounjaro, you may feel an uncomfortable sensation on your skin. It’s been described as like “pins and needles”, buzzing and burning. [34]

Why does this happen?

We still don’t know exactly why this is a side effect of GLP-1 treatment, and it's an area of continued study and research. [34]

Here's what we recommend to manage changes in skin sensation:

• If you can, wear loose clothing to avoid friction or pressure on the skin
• Moisturise your skin regularly
• Drink plenty of water to stay hydrated
• Aim for 7-9 hours sleep each night, as poor sleep may intensify the sensations
• If you’re feeling particularly uncomfortable, a cold compress may help

Contact your GP or call 111 if:

• You have noticed unusual skin feelings for more than a couple of days
• These unusual skin sensations are interfering with sleep or daily life

Important: Call 999 or go to A&E if:

• You suddenly notice weakness, drooping on one side of the face, trouble speaking, or changes in vision
• You experience a sudden loss of feeling, lose control of your bladder or bowels or have severe back pain

Fast pulse

What is it?

Some people notice heart palpitations, which may feel like your heart is racing, or a fast pulse at rest while taking Mounjaro. [1] This often only lasts for a few minutes at most.

Why does this happen?

This may happen because of changes in blood sugar levels, as well as dehydration caused by other side effects. [35] However, further research into the area is needed.

Here's what we recommend to manage a fast pulse:

• It’s worth keeping an eye on your resting heart rate with a fitness tracker, and noting any palpitations you experience
• Avoid triggers which may raise your heart rate, like caffeine, alcohol and smoking

Contact your GP or call 111 if:

• You notice repeated palpitations (racing or pounding heartbeat) that keep coming back or worsen.
• You have a history of heart problems in your family.

Although it's uncommon, it's important to be aware of a serious side effect of Mounjaro:

Inflamed pancreas (acute pancreatitis)

What is it?

Acute pancreatitis is an inflammation of the pancreas. It’s a serious, potentially life-threatening condition. You should see a doctor immediately if you experience any of the symptoms below.

Why does this happen?

Thankfully, the risk of developing pancreatitis white taking Mounjaro is low. [36] However, researchers are continuing to explore the link between acute pancreatitis and GLP-1 treatments. If you’ve ever had pancreatitis before, GLP-1 treatment may not be suitable for you. [1]

Here's what we recommend to manage pancreatitis:

Stop using this medicine and call 999 or go to A&E if you experience any of the following:

• Severe, persistent pain in the stomach area, which radiates to your back or underneath your right ribcage or right shoulder, that doesn’t go away and is so intense (8 or more out of 10) that you can’t focus on anything else
• Severe nausea and vomiting

Rare side effects

Rare side effects may affect up to 1 in 1000 people:

Severe allergic reactions (e.g. anaphylactic reaction, angioedema)

What is it?

A severe allergic reaction is a significant response that your body makes to coming into contact with something it perceives as being harmful.

Why does this happen?

Although rare, there’s a chance you may experience an allergic reaction to one of the ingredients in Mounjaro. [1]

Here's what we recommend to manage a severe allergic reaction:

Severe allergic reactions can be life-threatening. If you experience any of the following, stop taking your medication and call 999 or go to A&E immediately:

• Difficulty breathing, or swelling of your lips, tongue or throat and a fast heartbeat

Short-term side effects

The good news is that the majority of Mounjaro’s side effects are usually short-lived. You’re more likely to experience side effects, particularly digestive side effects like nausea and vomiting, in the first few weeks of treatment or when increasing your dose. These may last anywhere from a few days to a few weeks, but should ease as your body adjusts to treatment. [37]

Remember that side effects should be managed, not endured. If you’re experiencing mild side effects which are persistent or causing discomfort, speak to your healthcare provider. They may be able to recommend other treatments and therapies that can help.

If you experience any severe side effects, seek urgent medical attention.

Long-term side effects

Most side effects of Mounjaro are mild and short-term. [37] And, to date, studies haven’t identified any negative long-term side effects from treatment. [1] However, research is still ongoing.

If you have any questions or concerns about the long-term use of Mounjaro you should speak to your healthcare provider.

Understanding side effects

Why side effects may change week to week

You may experience different Mounjaro side effects from week to week as your body adjusts to the treatment. Some may last a few days, or a few weeks. You may also notice an increase in side effects each time you increase your dose. [37]

How do I know whether it's the GLP-1 medication causing the side effect?

If your side effects are mild, it may be helpful to keep a “side effects diary” to track any patterns.

For example, you may notice that your side effects are particularly noticeable shortly after taking your medication. If they’re persistent, or you find them difficult to manage, speak to your healthcare provider as there may be additional support that they can provide.

Remember, if you experience any severe side effects you must seek immediate medical attention.

Mounjaro safety and side effects FAQs

Are there different side effects in women and men?

Some early research suggests that people female at birth (AFAB) may experience side effects more than assigned male at birth (AMAB), specifically nausea and vomiting. [38] However, more research is needed to understand why this might happen.

Do side effects change depending on dose strength (e.g. 5mg or 7.5mg)?

At MedExpress, we believe that a gentle, gradual approach to weight loss treatment is best to support long-term, sustainable health goals. This means that, if you’re responding well to treatment, you may be able to increase your dose every 4 weeks until you reach your maintenance dose.

You’re more likely to experience side effects when you increase the strength of your dose (for example, if your Mounjaro dose increases from 2.5mg to 5mg). [37]

What to do if I take too much Mounjaro

If you use more Mounjaro than you should, talk to your doctor immediately. Too much of this medicine may increase the risk of side effects like low blood sugar, and make you feel unwell. [1]

Who should not take Mounjaro for weight loss?

Weight loss injections aren’t the right choice for everyone.

Before you begin treatment, you'll need to complete a clinical assessment. This is to check your eligibility, and to clarify any pre-existing medical conditions you have that may affect your suitability for treatment. It’s really important you share your full medical history with your healthcare provider, and keep them updated on any changes in your health or any other medications you may be taking.

Do not use Mounjaro if you have a personal or family history of a type of thyroid cancer called medullary thyroid carcinoma (MTC), or if you have Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). [1] If your personal or family history of either of these conditions changes, stop taking your treatment immediately and let your healthcare provider know.

You also shouldn’t take Mounjaro if you’re allergic to tirzepatide or any other ingredients in the medication. Severe allergic reactions are rare, but you should seek immediate medical attention if you experience side effects like lip, mouth or throat swelling or difficulty breathing.

If you have pre-existing conditions like kidney issues, a history of pancreatitis or gallbladder disease, or severe digestive problems, speak to your doctor before starting Mounjaro.

Is Mounjaro safe for people with diabetes?

Mounjaro is considered safe for people with type 2 diabetes. In fact, it's licensed in the UK to treat type 2 diabetes, as it helps to:

• Lower blood sugar
• Support your body make more insulin if needed
• Stabilise blood sugars by slowing digestion [1]

Mounjaro isn't licensed to treat type 1 diabetes.

If you live with type 2 diabetes and take Mounjaro, it's particularly important to monitor your side effects (especially any signs of low blood sugar). This is because you may be at a higher risk of experiencing hypoglycaemia (when your blood sugar drops below a healthy range). [39]

Symptoms of low blood sugar may include:

• Headache
• Drowsiness
• Weakness
• Dizziness
• Feeling hungry
• Confusion
• Irritability
• Fast heartbeat
• Sweating [1]

Mounjaro works by increasing insulin release (and lowering blood sugar) after eating. [40] When you combine it with other medications that lower blood sugar levels, it may cause your blood sugar to dip. [1]

This is why hypoglycaemia is more likely to affect you if you live with type 2 diabetes and you’re taking medication for it (like sulphonylurea, insulin or metformin). [1]

When to contact your GP or call 111:

• If you experience any of the above symptoms, you should call 111 immediately. If you’re having low blood sugar episodes often, it’s important to speak to your GP.

Important: When to call 999 or go to A&E:

• In rare cases, you could lose consciousness if your blood sugar drops too low. This is a medical emergency. If you think someone has very low blood sugar and they are not responding normally, call 999 or go to A&E.

Is Mounjaro from online pharmacies safe?

Yes, Mounjaro from UK online pharmacies should be safe, as long as it’s prescribed by a licensed and regulated pharmacy.

For example, MedExpress is regulated by the General Pharmaceutical Council (GPhC) for pharmacy dispensing and supply, and the Care Quality Commission (CQC) through its prescribing partners.

Make sure you check that an online pharmacy is fully registered and regulated before attempting to purchase treatment from them. They should also make sure you complete an initial online consultation before prescribing, to confirm your eligibility.

Is Mounjaro safe while pregnant?

No, Mounjaro should not be used if you're pregnant or trying to conceive. This is because we don't know how the medication could affect an unborn embryo or foetus.

MHRA guidance states that you should not take GLP-1 medications if you are pregnant, trying to get pregnant or breastfeeding, and that you should use adequate contraception while on the medication. If you’re considering having a baby, please speak to your clinician before you start trying to conceive. [41]

Remember, Mounjaro may make your oral birth control less effective. This is because it slows down how quickly food (and oral medication) leaves your stomach, which affects how well oral contraception is absorbed by your body. [42, 43] If you're experiencing digestive side effects like vomiting and diarrhoea, this may also mean your body doesn't have the chance to absorb the pill properly. [44]

Use condoms or switch to a non-oral method like an IUD to stay protected against pregnancy. This is particularly important for the first month after starting Mounjaro, and for the first month after each increase in dose. [1]

Is Mounjaro safe for kidneys?

There’s no current evidence to suggest that taking Mounjaro for weight loss may be harmful to your kidneys. However, certain side effects (like vomiting and diarrhoea) may cause you to lose fluids and become dehydrated, which can affect your kidneys. [1]

Also, you should let your healthcare provider know if you have a kidney (or liver) disease. This is because tirzepatide also contains benzyl alcohol. Large amounts of this could build-up in your body and cause “metabolic acidosis” (where there's too much acid in your blood). [1]

At MedExpress, we offer online consultations with regular clinical check-ins and a range of weight loss treatments, including Mounjaro, Wegovy Pen, Wegovy Pill and Foundayo. Our team can help you find the right treatment for you.

References

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