Mounjaro Dosage and Maintenance: A Complete Guide 

When you start using Mounjaro (tirzepatide), your healthcare provider will guide you through a structured dosing schedule. Starting at 2.5 mg for four weeks, your dose will gradually increase until you reach your maximum tolerated dose (up to 15 mg). 

Following your dosing schedule correctly is crucial to achieving your weight loss goals. Using the wrong dose or injecting at the wrong time could make Mounjaro weight loss injections less effective. It could worsen side effects, and you might end up wasting your medication. 

To help you use Mounjaro injections safely and effectively, this guide explains everything you need to know about dosage. You’ll learn what the starting dose is, how long you’ll remain on each dose, how to inject your Mounjaro KwikPen and more.  

And your journey doesn’t stop when you hit your target weight. Maintaining your success is just as important. We’ll also let you know how to maintain the weight you have lost – with or without Mounjaro. 

Mounjaro Dosage 

What Are the Mounjaro Doses? 

There are six different doses of Mounjaro. The 2.5 mg dose is the lowest dose available and 15 mg is the highest. 

• 2.5 mg 
• 5 mg 
• 7.5 mg 
• 10 mg 
• 12.5 mg 
• 15 mg

The Mounjaro Dosing Schedule 

Every Mounjaro patient has to follow the Mounjaro dosing schedule.  

The starting dose is the lowest dose of Mounjaro (2.5 mg). You’ll take this dose once a week for four weeks. After four weeks, your healthcare provider will prescribe you the next dose up (5 mg). 

Your prescriber will increase your Mounjaro dose in steps of 2.5 mg. This gradual increase is called “titration”. You’ll stay at each dose for at least four weeks until you reach the highest dose you can tolerate.  

After you’ve taken the 5 mg dose for four weeks, your healthcare provider will recommend one of two options. You either stay on the same dose or you move onto the next dose (7.5 mg), followed by 10 mg. If you can tolerate it, your clinician will prescribe you 12.5 mg, followed by the 15 mg dose. 

The decision to move up a dose will depend on a variety of factors. This might include starting body weight, how your body responds to the medication and underlying medical conditions. 

Mounjaro Titration: Why Is It Important? 

Titration allows your body to become accustomed to Mounjaro and build tolerance to the medication. This reduces the risk of side effects, like nausea, bloating and diarrhoea. So it’s important you don’t skip doses or move to higher doses too quickly. 

“The low starting dose is crucial,” Aamina Rafiq, Lead Pharmacist at Simple Online Pharmacy, explains. “It allows the medication to build up in your system safely, so your body can adjust to it.”

“Complete all four doses of your current pen before increasing strength, following manufacturer and prescriber guidance.

“You may not notice changes until you reach higher doses.”

Mounjaro Dosage Chart 

Each injectable pen contains four doses of Mounjaro, which you inject once a week. So one pen will last for one month. This dosage chart outlines the recommended titration schedule for Mounjaro:

What Is the Most Effective Mounjaro Dose? 

Clinical trials have shown that 15 mg is the most effective Mounjaro dose for weight loss. After 72 weeks, one study found patients lost on average:
 

• 16% of their starting body weight on a maintenance dose of 5 mg  
• 21.4% of their starting body weight on a maintenance dose of 10 mg 
• 22.5% of their starting body weight on a maintenance dose of 15 mg 
  

When Should I Inject My Mounjaro Dose? 

You should inject your Mounjaro dose on the same day each week. You also need to take it at the same time each week. It can be helpful to set a reminder on your phone. 

A lot of patients like to inject their dose in the evening, so they avoid potential side effects during the daytime. But you can choose any time that works for you.

Mounjaro Injection Sites: Where Should I Inject My Dose? 

You can choose where you inject Mounjaro. Suitable Mounjaro injection sites include the front of your thigh, below your belly button and the back of your upper arm. Each site has its benefits:
 

• Abdomen: Easy to reach and has a large surface area. This means you can change where on the abdomen to inject Mounjaro each week. It is often less painful because it has a layer of fat, which can also improve absorption. 

• Thigh: Large surface area and enough subcutaneous fat (under the skin) for effective absorption. It’s easy to see what you’re doing, which can give you better control.  

• Upper Arm: Easy to hide if you don’t want your injection site to be visible. You’ll need to inject it in the back of your arm, between your elbow and shoulder. This makes it hard to reach, so you’ll need someone to inject it for you. 

Choose a different injection site each week to avoid injection site reactions or infections. This means you can inject Mounjaro:  

• In the same area (e.g. abdomen), but in a different section of that area; or 
• In a different area. For example, if you injected Mounjaro in your thigh this week, you could inject it in your arm next week.
  

How to Use Mounjaro: Step-by-Step Instructions  

It’s natural to be a bit nervous before you inject your first dose, especially if you’ve never used a GLP-1 weight loss treatment before. But don’t worry, the pen is easier to use than you’d think. And you should only feel a small pinch.  

Here’s a step-by-step guide on how to use your Mounjaro injection. Make sure to read through the following instructions carefully before you inject your dose. 

Prepare to Inject Your Mounjaro Dose 

Your Mounjaro pen will arrive in secure, temperature-controlled packaging. Inside, you’ll find your KwikPen, filled with four doses to last four weeks. You’ll also find: 

• A leaflet that explains how to use Mounjaro 
• Single-use needles 
• A medical grade sharps bin (if you’ve ordered one)  

Check you’ve received the right medication and the correct strength. 

Before you inject Mounjaro, check that the liquid in the pen is clear. It should be free from any particles and should not be frozen or cloudy. Make sure your KwikPen is not expired or damaged. 

Wash your hands thoroughly with soap and hot water. Or use an antibacterial hand sanitiser. 

How to Administer the Injection 

You’ve washed your hands and checked that the pen contains the correct dosage, it’s not damaged and the liquid is clear. Now you’re ready to administer your dose.  

Before you inject the dose, you must prime the pen each time. So here’s how to do it: 

Prime Your Pen: 

1. Remove the pen’s cap and remove the paper tab from the outer needle shield. 

2. Select a new needle and attach it securely to the pen by placing it on straight. Twist the needle clockwise until it stops turning. The needle should pierce through the red seal. 

3. Keep the needle straight. If it’s at angle, it could bend or move, which can prevent the needle from attaching securely. This will result in your pen not working and you could waste your dose.
    
4. Once you’ve attached the needle, remove the outer needle shield. Keep it safe so you can use it again. 

5. You will also find an inner needle shield. Remove this shield before injecting the dose. You can throw this shield away.
    
6. Turn the knob on your pen until you hear two clicks and a line appears in the dose window.
    
7. Hold the pen so the needle is pointing up. Tap the cartridge holder to get rid of any air bubbles.  
8. Push the knob on the pen until a 0 icon appears in the window. Hold for five seconds. 

 
If a small amount of liquid comes out, you have successfully primed the pen.  

If the pen doesn’t release any liquid, check the needle is properly attached and that it has pierced the bulb of the pen. If the inner needle looks damaged, use a new needle and repeat these steps.

If the pen doesn’t release any liquid after the third attempt, get support from your prescriber.

“Please remember to prime your pen,” says Richard Wood, a pharmacist at Simple Online Pharmacy. 

“The number one reason pens break is that patients forget to prime the pen before use. They often don’t notice the needle isn’t inserted correctly and then the pen bursts.

“It should not feel hard to press down the dose plunger. If it is hard to press, stop what you are doing and call us first.”

Inject Your Dose: 

1. Turn the knob on your pen until the 1 icon appears in the dose window.
   
   Inject the needle at a 90° angle into your chosen site. Make sure the needle pierces your skin.
   
   
2. Push the knob until it stops. Hold for five seconds. Check the 0 icon has appeared in the window before you remove the needle. 
   
   If the 0 icon hasn’t appeared, insert the needle into a new injection site and administer the dose. You don’t have to reset it to 1.

After Injecting:  

1. If you notice a pinprick of blood, use a cotton bud and gently press it on the injection site. Don’t rub it.
    
2. Put the outer needle shield back on your pen and unscrew the needle to remove. Dispose of the needle in your sharps bin.
    
3. Put the cap back on your pen and store it safely. If there’s liquid in the pen after you have injected your fourth dose, do not use it. 

How to Store Your Mounjaro KwikPen 

You’ll need to store your Mounjaro KwikPen correctly when you receive it.  

Refrigerate it at 2℃ to 8℃ before the first use. This will maximise its shelf life if you’re not using the pen straight away. 

After using the first dose from your pen, you can keep Mounjaro out of the fridge for up to 30 days, at a temperature below 30℃. So only remove the pen from the fridge when you’re ready to start using it. 

Can I Inject the Extra Dose? 

No, it’s not safe to inject the “fifth dose” or “golden dose”. These terms refer to the small amount of liquid left in your Mounjaro pen after your fourth dose. 

This “buffer” liquid is there to make sure there’s enough liquid in the pen for each dose. Injecting this liquid can lead to under or over-dosage, each of which carries its own risk.  

If you try to inject this buffer liquid, you also risk damaging the pen. This makes it unsafe to use.

Can I ‘Microdose’ or Split Mounjaro Doses? 

No, you should not microdose Mounjaro or split your injection into smaller doses. 

The manufacturer of Mounjaro measures the doses precisely. Altering the dose amount can cause underdosing, making it ineffective, or overdosing, which raises the risk of complications. 

No clinical evidence proves microdosing Mounjaro is effective either. Most claims supporting the practice are anecdotal.

What Happens If I Miss a Dose? 

When life gets busy, you might forget to administer your Mounjaro injection on your chosen day. If you miss a dose, it’s really important you follow this guidance:
 

• Within four days of your scheduled injection, take your dose as soon as possible and continue with your regular schedule.  

• If more than four days have passed, skip the missed dose and take your next injection on the regularly scheduled day. 

• If it’s been seven to 14 days since your scheduled injection, take the injection as soon as you remember. Use that day as your new injection day going forward. 

• If you’ve missed more than one dose, consult your healthcare provider for advice on how to safely restart treatment. 

Mounjaro Maintenance: How to Keep the Weight Off 

Losing weight and reaching your health goals is a huge achievement. So take some time to celebrate your success. 

However, your treatment plan doesn’t stop when the scale hits your target weight. Keeping it off is equally as important. So you’ll need to understand how to maintain your weight loss. 

What to Do When You Reach Your Goal Weight 

Once you’ve reached a weight you’re happy with, you have two choices. You can keep using Mounjaro to maintain your weight loss. Or you can stop taking it and use healthy habits to keep the weight off. 

Maintaining Weight Loss Without Mounjaro  

If you stop taking Mounjaro, there is a chance you will gain at least some of the weight that you have lost back. In one randomised trial, those who switched from Mounjaro to a placebo after 36 weeks experienced weight regain of 14%. That’s why some patients prefer to continue taking the treatment for long-term weight management. 

However, weight regain isn’t inevitable if you stop taking the medication. During your treatment, your prescriber will encourage you to eat a healthy diet. They’ll also recommend you exercise and take better care of your emotional wellbeing. 

Maintaining positive lifestyle changes you’ve built over the course of your treatment will help you keep the weight off beyond Mounjaro. It’s important to take things slow and make small changes to diet and exercise that last.

You don’t have to stop using Mounjaro immediately. You can gradually decrease your dose, which gives you time to make your new lifestyle a habit. 

Maintaining Weight Loss With Mounjaro 

It’s normal to feel anxious at the thought of stopping weight loss medications. Mounjaro works by suppressing your appetite. So some patients find it hard to maintain their weight loss as their appetite returns to pre-Mounjaro levels. That’s why some choose to stay on Mounjaro to maintain their weight loss. 

Once you reach your weight loss goals, your clinician can prescribe your weight loss medication for maintenance. At Simple, we can do this even if your BMI is within a healthy range.  

However your clinician will only continue prescribing Mounjaro if you’re still benefiting from it. Like if you’re maintaining weight loss, not experiencing side effects and you’re not hearing much food noise. 

The Mounjaro Maintenance Dose 

The maintenance dose of Mounjaro is the dose you take to maintain your weight loss.  

Only certain doses of Mounjaro are licensed for maintenance. The Mounjaro doses approved for maintenance are 5 mg, 10 mg and 15 mg.  

Your healthcare provider may be able to prescribe 2.5 mg, 7.5 mg and 12.5 mg for maintenance. Clinicians call this “off-label” use, meaning it falls outside the usual licensing terms. This decision will depend on individual needs. 

The right maintenance dose for you will depend on several factors. This might include your weight loss goals and how well your body tolerates the medication. The goal is to achieve steady, effective weight loss while also experiencing minimal side effects.  

Your healthcare provider will help you determine your ideal maintenance dose and tweak your dose as necessary. 

How Long Can I Take Mounjaro For? 

There is no limit on how long you can use Mounjaro for.  

However your healthcare provider will only continue prescribing Mounjaro if you are still benefiting from it. They will review your progress and provide recommendations. 

Is Mounjaro Safe for Weight Loss?

Yes, Mounjaro is safe for weight loss. The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) licensed and authorised Mounjaro for weight loss in 2023.  

Most users tolerate Mounjaro well. However, like all medications, Mounjaro does have side effects. The most common side effects, affecting more than one in 10 patients, are gastrointestinal (stomach-related). These include:  

• Nausea  
• Diarrhoea  
• Vomiting  
• Constipation  
• Stomach pain 
  

There is also a risk of serious side effects, although these are less common. Pancreatitis is an uncommon side effect, which may affect one in 100 patients. Severe allergic reactions, like anaphylaxis, are a rare side effect, which may affect one in 1,000 patients. 

Mounjaro isn’t suitable for everyone, either. For example, you shouldn’t use Mounjaro if: 

• You’ve been diagnosed with – or you have a family history of – medullary thyroid cancer (MTC) 
• You have kidney disease 
• You’re pregnant or breastfeeding 
  

A clinician will assess you and only prescribe Mounjaro if it’s safe.

Get Support for Mounjaro Dosage and Weight Maintenance 

Understanding the correct dosing schedule is key to achieving long-term success on Mounjaro. But dosage varies from person to person – what works for one person might not work for you. Your healthcare provider will work alongside you to determine the best dose for you. 

Remember you’re not alone. Whether you’re just beginning your treatment or maintaining your weight loss, we’re here to support you every step of the way.  

If you have any questions about your dosage or concerns about how to use your injection, contact us for tailored support. Or call us on 0141 774 5023. 

You can also download our Renu app for more guidance on how to use and manage your medication. You’ll find resources to help you during your weight loss journey from our team of healthcare professionals. This includes dietitian-backed recipes, exercise tips and a progress tracker.

 

References 

mounjaro.lilly.com. (n.d.). How to Use, Dosing & Side Effects | Mounjaro® (tirzepatide). [online] Available at: https://mounjaro.lilly.com/how-to-use-mounjaro#how-to-use 

NICE. (n.d.). Tirzepatide [online] Available at: https://bnf.nice.org.uk/drugs/tirzepatide/  

Medicines.org.uk. (2024). Mounjaro KwikPen 10mg solution for injection in pre-filled pen – Patient Information Leaflet (PIL) – (emc). [online] Available at: https://www.medicines.org.uk/emc/product/15484/pil  

Jastreboff, A.M., Aronne, L.J., Ahmad, N.N., Wharton, S., Connery, L., Alves, B., Kiyosue, A., Zhang, S., Liu, B., Bunck, M.C. and Stefanski, A. (2022). Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine, 387(3). doi:https://doi.org/10.1056/nejmoa2206038.

 
‌Aronne, L.J., Sattar, N., Horn, D.B., Bays, H.E., Wharton, S., Lin, W.-Y., Ahmad, N.N., Zhang, S., Liao, R., Bunck, M.C., Jouravskaya, I., Murphy, M.A. and SURMOUNT-4 Investigators (2023). Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial. JAMA, [online] 331(1). doi:https://doi.org/10.1001/jama.2023.24945.

Clinically reviewed by: Richard Wood, GPhC reg: 2078802