Join the community

Everything you need to know about Mounjaro for weight loss

Everything you need to know about Mounjaro for weight loss, how tirzepatide helps you lose weight and how to use Mounjaro injections.
Mounjaro injection pens

Have you heard of the weight loss drug Mounjaro? If so, you probably have a lot of questions, like how does it work? Is it safe? How can I start this treatment? At myBMI we have weight management specialists who have all the information you need when looking into losing weight. We’re going to tell you everything you need to know about Mounjaro for weight loss.

What is Mounjaro?

Mounjaro is an injectable prescription medication with the active ingredient tirzepatide. The NHS prescribes it alongside exercise and a healthy balanced diet to treat adults with type 2 diabetes. However, private clinics like ourselves are licensed to prescribe Mounjaro for weight loss, as it is now known to be highly effective in helping to drop weight.

How does Mounjaro work?

This medication is made for treating type 2 diabetes, where the body does not make enough insulin to control the level of glucose in the blood or when the body cannot use insulin effectively, leading to unbalanced blood glucose levels. 
The active ingredient tirzepatide mimics a gut hormone ( GLP-1) which sends a signal to the brain to tell you that you are full. It also slows down your digestive system, meaning it takes longer to break down food and empty the stomach. It’s recommended to stop eating when you feel full while on Mounjaro as this is one of the main factors that causes the weight to drop off.

How does Mounjaro help with weight loss?

It has been shown to decrease food intake and increase energy expenditure, which results in weight loss. While working with a GLP-1 it has more of a positive effect on blood glucose and body weight. Mounjaro also slows the movement of food from the stomach into the small intestine, meaning that food takes longer to digest – leaving you feeling fuller for longer. This leads to you having less of an urge to eat and stops you from overeating and gaining weight. When working alongside a healthy balanced diet it causes weight loss.

How long does Mounjaro take to start working?

Mounjaro starts working as soon as it is injected into the body. However, the time it takes to see a difference in blood sugar levels and weight may vary. Some people see a difference after just a few weeks of treatment, but if you have any questions about how long the treatment will be you should speak with your doctor or a professional, as everybody is completely individual when it comes to weight loss treatments.

What are the side effects of Mounjaro?

Some of the reported side effects of Mounjaro include:

  • Nausea 
  • Diarrhoea
  • Vomiting
  • Constipation
  • Indigestion
  • Stomach pains

These side effects were reported by less than half of patients taking Mounjaro injections, and just over 3% of patients had to stop treatment due to side effects (which is a very small amount). It’s recommended to have anti-sickness tablets and heartburn medication at hand just in case you experience any of these side effects.

It’s also worth noting that myBMI can provide any medication needed to treat side effects as part of your monthly plan with no extra charge.

How to use Mounjaro injections and control dosage

What is a safe dosage of Mounjaro?

For the first 4 weeks of treatment, you will be prescribed a 2.5mg pre-filled injection pen which you should inject once weekly. It’s important to note that you must complete the full 4 weeks of this dose before increasing the dosage to avoid side effects.

You will then move onto a 5mg once-weekly injection, for at least 4 weeks and continue this treatment for as long as you see fit. Again, you must complete 4 weeks of treatment before increasing the dosage if necessary.

If additional treatment is needed, after 4 weeks of 5mg, you should then move onto 7.5mg for at least 4 weeks, then 10mg, and 12.5mg with the strongest dose being 15mg. 

If you miss a dose or have any concerns about the dosage you have been prescribed you should speak to a doctor/professional.

How to use the Mounjaro pen (step-by-step)

Step 1: Choose the injection site

This is usually your thighs, the back of your upper arm, or your stomach (at least an inch away from your belly button). Choose an area where you can pinch about an inch of your skin for a painless injection. Remember to rotate and massage the area before injecting each time you inject.

Step 2: Pull off the base cap to reveal the needle

Be careful, the needles are sharp.

Step 3: Place the base flat on your skin, and unlock the pen by twisting anti-clockwise

Step 4: Press and hold the button for up to 10 seconds

Listen for the first click, which means the injection has started. The second click tells you that the injection is complete.

How to store your Mounjaro pen

You can keep your Mounjaro injections unrefrigerated for up to 21 days, provided that it does not exceed a room temperature of 30°C. Alternatively, you can refrigerate them in their original carton at any temperature between 2°C and 8°C. If you feel uncomfortable injecting cold medication, you can take this out of the refrigerator up to an hour before you inject.

When not to use the pen:

If your Mounjaro injections have been left at room temperature for longer than 21 days, you shouldn’t use them Instead, you should open a fresh pen that has been stored at the correct temperature and is in date. Do not use your pen if the liquid has been discoloured or changed consistency. You should remember to always check the expiration date, and don’t use an expired pen.

How to dispose of your Mounjaro pen

You shouldn’t dispose of your Mounjaro pen in a normal bin or bin bag, as the needle is sharp and you risk injuring yourself and others. Instead, dispose of the pen into a sharps container (a needle bin) and keep it out of reach of children and pets.
We offer an optional sharps container, free of charge and included in your myBMI monthly plan. They can be collected by your local council upon request. Call your local council or visit their website to arrange this.

Things to keep in mind when starting your Mounjaro journey

  • Each pen is a single-dose pen that should be taken once weekly.
  • Always read the instructions before use.
  • Stop eating when you feel full.
  • Eat smaller amounts more frequently – for example, split your 3 meals a day into 4 smaller meals.
  • Keep a healthy diet. Avoid fatty foods and make sure your diet covers all of the major food groups. If you have side effects, try to eat some dry foods like crackers rice, etc.
  • Always remember that your weight loss journey is individual to you – don’t compare your results to others.
  • This is a prescription medication that shouldn’t be taken otherwise. Do not share your pens!

You can learn more about Mounjaro in our helpful medical therapy guides, or if you feel that you are ready to start your weight loss journey with Mounjaro, you can consult one of our weight loss specialists.

Content Written By

Morgan Pennington

Morgan Pennington

Reviewed & Fact-Checked By

Table of Contents

myBMI colour logo heart

Content Written By

Reviewed & Fact Checked by

James O'Loan

James O'Loan

How we ensure accuracy in our content

More Content We Think You'll Love

Foods to avoid on Mounjaro
Diet & Nutrition Advice

When to eat and foods to avoid while taking Mounjaro

As we know, when undergoing any weight loss treatment, it’s always best to have a healthy diet and lifestyle to boost treatment and get the full effect. But each treatment has slightly different effects on the body and metabolism, meaning sometimes the average “healthy diet” doesn’t always work the best. There are certain foods and drinks that you should be avoiding whilst taking Mounjaro for weight loss.

Read More »