What is Mounjaro?

Mounjaro is a type of medication you might need to take if you have type 2 diabetes.

• What is Mounjaro used for? 
• How does Mounjaro work? 
• Is Mounjaro available across the UK? 
• Who can take Mounjaro? 
• How is Mounjaro taken? 
• Your Mounjaro prescription 
• Mounjaro side effects 
• More information and support with Mounjaro

What is Mounjaro used for? 

Mounjaro, the brand name for tirzepatide, is a drug that lowers blood sugar levels.  

How does Mounjaro work? 

This medication works by activating two receptors called GLP-1 and GIP to increase the level of incretins – hormones - in the body.  

It works by helping your body to produce more insulin when needed. It also reduces the amount of glucose, or sugar, produced by the liver, and slows down how quickly food is digested. This all helps to lower blood sugar levels and HbA1c.   

Is Mounjaro available across the UK? 

Yes for treating type 2 diabetes. It can be prescribed in England, Wales and Northern Ireland. The Scottish Medicines Consortium, or SMC for short, has also approved the use of Mounjaro to treat type 2 diabetes.   

Who can take Mounjaro? 

Treatment for type 2 diabetes  

Adults over the age of 18 years with type 2 diabetes can take Mounjaro. 

Guidelines from the National Institute for Health and Care Excellence, or NICE for short, recommend that Mounjaro can be prescribed to adults with type 2 diabetes when:

• Using three medications has not been effective in managing diabetes.
• Or you have not been able to take the medications. This might be because of side effects or because of another medical condition.

Mounjaro is only prescribed for people who also have a Body Mass Index, known as BMI, of 35kg/m2 or more, and additional psychological or other medical conditions that are related to obesity. 

However, someone with type 2 diabetes can be prescribed Mounjaro if you have a BMI below 35kg/m2 and: 

• Using insulin would affect your job due to the risk of low blood sugar, also known as hypoglycemia, or hypos; 
• Weight loss would lead to improvements in other obesity-related health issues. 

NICE recommends – due to their risk from obesity-related health problems at a lower BMI – that people from Black African, African-Caribbean, Asian, South Asian, Chinese, and Middle Eastern backgrounds receive treatment with Mounjaro at a lower BMI.   

Is Mounjaro a medication for weight loss?  

Mounjaro is not yet available as a medication for weight loss within the NHS. 

In December 2024, NICE published their final draft decision of Mounjaro for treating obesity, the final decision is expected sometime in January 2025.

NICE have recommended Mounjaro for use as a medication for weight loss on the NHS when someone has a BMI of at least 35kg/m2, and they have additional medical conditions that are related to obesity including type 2 diabetes and those who are at high risk of type 2 diabetes.  

Under the draft NICE guidelines, a lower BMI would apply to people for people from Black African, African-Caribbean, Asian, South Asian, Chinese, and Middle Eastern backgrounds, who have additional medical conditions that are related to obesity.   

Normally, NHS England have three months after a NICE decision to make a new drug available to those who are eligible but due to the associated high costs and current lack of support services, they are planning to gradually roll it out over a 12-year period for the eligible population in England.  

We are awaiting more detail from NHS England on how Mounjaro will be prioritised for people living with obesity in England.

NICE have approved the time period that NHS England asked for, which will see a minimum of 220,000 people living with obesity taking Mounjaro within a three-year period. Based on their initial proposal we expect those who have the greatest clinical benefit from weight loss to be prioritised before a wider expansion of the drug’s availability.

It is not yet clear when people who are high risk of type 2 diabetes, or people with type 2 will be on the priority list (though this decision does not affect you if you are prescribed Mounjaro for your type 2 diabetes). 

There are shortages of GLP-1 agonists 

We know that due to global shortages of GLP-1 agonists, some people living with type 2 diabetes who could benefit from these medications are unable to access it.  

You might also be offered Mounjaro if you’re unable to access your usual GLP-1 agonist medication. 

Since March 2024, Mounjaro can also prescribed to people with type 2 diabetes in England who are unable to obtain Ozempic, Trulicity or other GLP-1 agonist medications.    

If the shortages of these medications have impacted your diabetes treatment and you’re looking for more information we have a GLP-1 shortages FAQ.   

You can also read our response to the serious supply issues of these drugs for people with type 2 diabetes. 

Your healthcare team will contact you if shortages of these medications could affect the availability of your medication and discuss this with you. But if you are concerned or have questions about these shortages then you can ring our helpline – call 0345 123 2399. 

Who can’t take Mounjaro? 

Some medications might not be suitable for some people, which might be because of medical conditions or other reasons: 

You should not take this medication if you are pregnant. Speak to your healthcare professional for advice before taking Mounjaro if you are breastfeeding or planning a pregnancy. 

You might not be able to take Mounjaro if you have delayed gastric emptying.

When you start a new medication always check with your healthcare team that it’s suitable for you to take.   

How is Mounjaro taken? 

Mounjaro is an injection that you take once a week. Your healthcare team will give you more information about how to take it, and how to inject.   

There are different types of injections that you can use to take Mounjaro. You can take it through a one-dose pen or a multi-dose pen called the Mounjaro Kwikpen.  

The Mounjaro Kwikpen comes as a four-dose pre-filled injection pen which you take at a starting dose of 2.5mg once a week for four weeks.    

Lower strengths are available now through the Mounjaro Kwikpen - 2.5mg/0.6ml and 5mg/0.6ml solution for injection in 2.4ml pre-filled pens (containing four doses). Higher strengths are expected to be made available later this year.   

Always take this medication exactly as your healthcare team has told you. The Patient Information Leaflet inside the box will tell you how to take it but always check with a doctor or pharmacist if you are not sure.     

Your Mounjaro prescription 

You should only be given a prescription for Mounjaro following an assessment by your healthcare team to make sure that you meet the criteria and that you’ll benefit from its use. 

This should be an individual assessment that includes how Mounjaro will fit into your current treatment plan and considers any diet or activity programme that you are following, as well as the risk of side effects, the dose you’ll need, and your personal choices. 

Your healthcare team should explain your prescription to you but it's important to make sure you ask if you don't feel you know enough.   

And make sure you talk to your GP or your diabetes team if you struggle to take Mounjaro. They might be able to help by giving you a different dose.   

In England, if you need to take any medication to manage your diabetes, your prescriptions will be free. Ask your healthcare team about a prescription exemption certificate if you don't have one, to make sure you don't get charged for your medication. Prescriptions are already free for everybody in the rest of the UK, so you shouldn't pay for your medication. 

Mounjaro side effects 

Like all medications, Mounjaro can cause side effects. But when side effects are listed as common in the Patient Information Leaflet, it doesn’t mean that everyone who takes the medication will get them.   

The information about side effects is based on the likelihood of people having them. For example, if a side effect is very common then it can affect more than one in ten people, and if a side effect is very rare then it affects fewer than one in 10,000 people.   

Because medicines can affect people differently, your healthcare team will speak to you about what’s best for you and discuss any side effects.  

Common side effects can include: 

• feeling sick 
• indigestion 
• constipation 
• diarrhoea. 

Risk of low blood sugar 

When taken on its own, Mounjaro does not usually cause blood sugar levels to become too low. However, hypos are more likely to happen when you take it with other diabetes medications such as insulin or a sulphonylurea. 

Your healthcare team may advise reducing the dose of your sulphonylurea or insulin medicine when you start taking Mounjaro to reduce the risk of hypos. 

Risk of high blood sugar 

If you take Mounjaro with insulin, and your insulin is reduced too quickly it can cause high blood sugar levels, this is called hyperglycaemia, and there is an increased risk of diabetic ketoacidosis, also called DKA. Your healthcare team should discuss with you the signs and symptoms of DKA. 

These are not all the side effects. You will find a full list of known side effects in the Patient Information Leaflet. This comes in the medication box. 

It’s also important that you take individual advice from your healthcare team before starting treatment and report any side effects to your healthcare professionals, if you experience any.  

You can also report these side effects to the Yellow Card Scheme, which is the government system used for recording side effects with medicines in the UK.   

More information and support with Mounjaro 

Still have more questions? Or is there anything you're not sure about Mounjaro after reading this page? Contact our helpline on 0345 123 2399. 

You can visit the NHS website for more information.