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Does Mounjaro Make You Tired? It Can, Says Sleep Doctor

Tiredness isn’t listed as a side effect of Mounjaro from clinical trials, but users report it. More research is needed as use increases.
Written by
Jeff Kahn, M.S., Rise Science Co-Founder
Reviewed by
Chester Wu, MD, Rise Science Medical Reviewer
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Does Mounjaro Make You Tired?

  • Tiredness isn’t listed as a side effect of Mounjaro, but users have reported that the drug makes them tired. 
  • Other side effects of Mounjaro — like gastrointestinal issues and anxiety — can make it hard to get enough sleep.
  • Take steps to feel less tired with the RISE app. RISE can help you catch up on lost sleep and sync up with your body clock. Plus, it can guide you through 20+ sleep hygiene habits to help you fall and stay asleep.

Mounjaro is a weekly tirzepatide injection that’s FDA-approved for those with type 2 diabetes. Although it’s designed to help type 2 diabetics manage their blood glucose, it can also be prescribed off-label for weight loss and weight management for those with obesity. 

Clinical trials didn’t find tiredness as a side effect, but users are reporting otherwise. 

Below, we’ve covered why Mounjaro can make you feel tired and how you can use the RISE app to get more energy. 

Heads-up: Mounjaro is a relatively new drug, so there’s a lot we don’t know about its side effects. Scientific research is lagging behind the increase in users.

Advice From a Sleep Doctor

Advice From a Sleep Doctor

“In the clinical trials we have so far, tiredness isn’t reported as a side effect of Mounjaro,” says Rise Science medical reviewer Dr. Chester Wu,a double board certified doctor in psychiatry and sleep medicine.

“However, some users report feeling tired on Mounjaro, and the drug can cause side effects, like vomiting and diarrhea, which can make it hard to get enough sleep.”

Can Mounjaro Make You Tired?

Mounjaro may make you feel tired. Tiredness isn’t listed as a side effect of Mounjaro, but users have reported it online. And Mounjaro can cause side effects — like GI issues — which can disrupt your sleep. 

The Food and Drug Administration (FDA) doesn’t list tiredness as a side effect of Mounjaro, but that conclusion comes from a handful of clinical trials

The FDA states clinical trials are conducted under “widely varying conditions” and rates of side effects “may not reflect the rates observed in practice.” In non-trial conditions, there are many factors that could impact side effects, including health conditions and medications.

Plus, these trials included people with type 2 diabetes, so it’s unclear whether Mounjaro could cause fatigue in those without the health condition. 

And to be listed as a common side effect, it has to occur in 5% or more of users. It’s unclear whether fatigue happens in a smaller percentage of users. This may sound small, but as use of the drug increases, this can end up affecting a lot of people.  

Fatigue is listed as a side effect of Zepbound, which contains the same active ingredient (tirzepatide) in the same doses as Mounjaro. 

Beyond scientific research, there are anecdotal reports of Mounjaro causing tiredness. 

Some users report feeling tired when taking a 5-mg dose of Mounjaro, but not the starting 2.5-mg dose. Others report fatigue on the day they take Mounjaro and for the next two days, feeling tired after eating, or getting tired more quickly after exercise. 

Research from 2023 published in Brain Sciences analyzed Reddit, YouTube, and TikTok posts about the side effects of semaglutide and tirzepatide type 2 diabetes and weight loss drugs, including Ozempic, Wegovy, Rybelsus, and Mounjaro.

Users mentioned sleep-related issues the most, such as insomnia, anxiety, depression, and general mental health issues. Some said tirzepatide triggered insomnia.  

Heads-up: Tiredness and sleepiness aren’t the same thing. Tiredness is when you feel fatigued, but you might not be able to fall asleep. Sleepiness is when you could fall asleep if you tried. Mounjaro may cause tiredness and sleepiness (more on why soon). 

Because this gets confusing: Tirzepetide — the active ingredient in the drugs Mounjaro and Zepbound — is a dual-acting glucagon-like peptide-1 receptor agonist (GLP-1 receptor agonist) and a glucose-dependent insulinotropic polypeptide (GIP) receptor agonist, or GLP-1/GIP receptor agonist. Semaglutide — the active ingredient in Ozempic, Wegovy, and Rybelsus — is only a GLP-1 receptor agonist. 

As a dual-acting receptor agonist, Mounjaro can be a more effective treatment for type 2 diabetes and obesity, as it targets multiple pathways involved in glucose regulation and weight management, compared to single-acting receptor agonists like Ozempic. But this may mean it comes with more fatigue. More research is needed into all of these weight loss and diabetes medications. 

We’ve covered more on GLP-1 receptor agonists: 

And GLP1/GIP receptor agonists: 

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Why Does Mounjaro Make Me Tired? 

It’s unclear why Mounjaro makes you tired. It may be due to eating fewer calories, low blood sugar, changes in dopamine levels or exercise, or side effects like GI issues and anxiety disrupting your sleep. 

Here’s more on how Mounjaro can make you tired: 

  • Eating fewer calories: Mounjaro suppresses your appetite, leading to you eating fewer calories. Your body may feel tired as you have less fuel, and this may feel worse if you’re not used to being in a caloric deficit. 
  • Hypoglycemia (low blood sugar): Mounjaro may increase your risk of hypoglycemia if you take drugs like sulfonylurea or insulin alongside Mounjaro. Symptoms of hypoglycemia include drowsiness, mood issues, anxiety, feeling weak, and restless sleep. You may get nocturnal hypoglycemia (low blood sugar at night) and experience morning tiredness.
  • Changes in exercise: It’s usually recommended you exercise more on Mounjaro, but exercising while eating fewer calories can leave you feeling drained. On the flip side, fatigue or GI issues could make exercising tough, but not exercising can make it harder to fall asleep and also leave you feeling sluggish. 
  • GI side effects: Mounjaro can cause digestive problems like nausea, indigestion, and abdominal pain, which can make it harder to sleep. Plus, vomiting and diarrhea can dehydrate you, causing fatigue. 
  • Anxiety and depression: Anxiety and depression aren’t listed as potential side effects of Mounjaro, but users have reported them online. Depression and thoughts of suicide are listed as side effects of Zepbound. Even if you don’t experience mental health issues, you may feel stressed about drug interactions or GI issues, and this can make it harder to sleep. RISE users say stress and anxiety are the biggest hurdles getting in the way of a good night’s sleep.
  • Increase in heart rate: One possible side effect of Mounjaro is an increased heart rate of two to four beats per minute. Some users have reported episodes of sinus tachycardia, or a faster-than-usual heartbeat. Anxiety can spike your heart rate further. More research is needed to find out if this increased heart rate could affect your sleep. 
  • Changes in dopamine: Some 2023 research suggests GLP-1 receptor agonists could affect dopamine, the neurotransmitter involved in mood and motivation. These changes may leave you feeling low and unmotivated. A lower mood is linked to lower alertness, so this could impact your energy levels and even sleep. More research is needed to know if GLP-1/GIP receptor agonists, like Mounjaro, affect dopamine. 

You may also feel tired due to the common culprits of high sleep debt and circadian misalignment, which can tank your energy whether you’re on Mounjaro or not. We cover how to fix those soon. 

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Does Mounjaro Affect Sleep? 

Mounjaro can affect sleep by causing side effects like vomiting, diarrhea, anxiety, and depression. You may also change your diet and exercise habits on Mounjaro, which can impact sleep. For example, hunger pangs from cutting calories can keep you up at night, and exercising less can make it harder to drift off.

Does Mounjaro Cause Insomnia? 

Mounjaro may cause insomnia. A 2023 study into social media reports of GLP-1 receptor agonist side effects found some users reported their insomnia got better, while others said it got worse. There were reports of tirzepatide triggering insomnia in some. 

Mounjaro may cause sleep problems that look a lot like insomnia. But it’s not clear whether these sleep problems can be classified as clinical insomnia. 

The International Classification of Sleep Disorders (ICSD-3) defines insomnia as having: 

  • Trouble falling asleep or staying asleep, or waking up too early 
  • Trouble sleeping despite having the opportunity to sleep 
  • Daytime distress or impairment from sleep problems 
  • Sleep problems that are not better explained by another sleep disorder or medical condition 

Having these sleep problems at least three nights a week for at least three months could be a sign of insomnia. Having them for one to three months could be a sign of episodic insomnia.

Seek medical advice if you think you have insomnia. You may need different, or additional, treatments compared to other Mounjaro sleep problems.

Does Mounjaro Improve Sleep? 

Mounjaro may improve your sleep, either straight away or with time. As a diabetes treatment, Mounjaro can help type 2 diabetics manage high blood sugar levels. And as diabetes is linked to sleep disturbances and sleep disorders like sleep apnea, better management of the condition may lead to better sleep. 

Mounjaro can also help you lose weight, which may reduce snoring, sleep apnea, and your odds of health conditions like high blood pressure and heart disease — which have been linked to sleep disorders like insomnia. 

GLP-1 receptor agonists may improve sleep apnea outside of weight loss. We’ve covered more on whether Ozempic can potentially help sleep apnea here.

Healthy lifestyle changes are usually encouraged on Mounjaro, and these can help you sleep. You may start exercising or eating smaller, healthier meals. 

Mounjaro may even reduce your cravings for alcohol and cigarettes, and cutting down on these can also improve your sleep.

Plus, the 2023 research we mentioned earlier found reports of tirzepatide helping some people wake up feeling refreshed and rested. And GLP-1/GIP receptor agonists helped improve insomnia, anxiety, and depression for some. 

Learn how sleep helps you lose weight here.

How Long Does Mounjaro Fatigue Last? 

It’s unclear how long Mounjaro fatigue lasts. Fatigue may improve as your body gets used to the drug. You may also start sleeping better as other side effects improve. 

You’d usually stay on a dose of Mounjaro for four weeks before moving up to a higher dose. GI issues tend to happen when your dose increases, but it’s unclear whether the same happens with fatigue. Long-term studies are needed. 

What Are the Side Effects of Mounjaro? 

The common side effects of Mounjaro include: 

  • Nausea
  • Diarrhea
  • Decreased appetite 
  • Vomiting
  • Constipation 
  • Indigestion 
  • Abdominal pain

These side effects were reported by 5% or more of users in clinical trials. It’s not clear whether Mounjaro caused fatigue in a smaller percentage of people.

Serious side effects include allergic reactions, pancreatitis (inflammation of the pancreas), diabetic retinopathy complications, kidney problems, and gallbladder problems like gallbladder disease. 

Mounjaro has a boxed warning of an increased risk of thyroid C-cell tumors and a thyroid cancer called medullary thyroid carcinoma (MTC).

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How to Improve Mounjaro Fatigue? 

You can improve Mounjaro fatigue by paying back sleep debt, getting in sync with your circadian rhythm, improving your sleep hygiene, managing GI issues and anxiety, eating a balanced diet, and getting some exercise. 

Here’s how:

  • Pay back sleep debt: Sleep debt is the amount of sleep you owe your body. The more sleep debt you have, the more tired you’ll feel. This is true whether you’re taking Mounjaro or not. Try taking short afternoon naps, heading to bed a little earlier, or sleeping in a little later to catch up on sleep. RISE works out how much sleep debt you have each day.
  • Get in sync with your circadian rhythm: Your circadian rhythm is your body’s internal clock. Keep a regular sleep schedule, even on weekends, and eat meals at regular times. This helps you sync up with your circadian rhythm, which can boost your energy. RISE predicts the timing of circadian rhythm each day and shows you when your body naturally wants to wake up and go to sleep.  
  • Improve your sleep hygiene: These are the daily behaviors that help you fall faster and wake up less often at night. RISE tells you the best time to do 20+ habits based on your circadian rhythm, including when to stop eating each day and when to get and avoid bright light. 
  • Manage GI issues: Avoid fried and fatty foods, and go for bland options like rice or crackers. Smaller, more frequent meals can help with nausea, and staying hydrated is even more important. Research from 2022 shows sleeping on your left may help with heartburn. We’ve covered how to sleep with acid reflux and stomach pain here.
  • Manage anxiety: Try exercising during the day, and spending plenty of time unwinding before bed. Meditating, journaling, and breathing exercises may help. Learn how to sleep with anxiety here.
  • Eat a balanced diet: Eat plenty of fruits, veggies, complex carbs, fiber, and protein to give your body the right fuel. Learn which foods give you energy here. 
  • Get some exercise: Exercise can keep anxiety in check, boost daytime energy, and help you drift off at night. If Mounjaro side effects make exercising tough, try a short walk or at-home yoga video to get some movement in.  
  • Talk to a healthcare professional: Your prescribing healthcare provider may recommend changes to any prescription drugs or over-the-counter supplements you take. They may recommend taking Mounjaro at a different time of day (drug timing can make a difference!) or using a different injection site. Some users have reported feeling better when changing their injection site from their stomach to their upper arm.

We’ve covered more ways to stop feeling tired here.

RISE app screenshot showing sleep hygiene habit reminders
RISE can send you personalized sleep hygiene reminders.

The best way to feel less tired is to get the right amount of sleep for you. RISE calculates how much sleep you individually need. Despite what you may hear, it’s not simply eight hours for everyone. When we looked at how much sleep 1.95 million RISE users aged 24 and up needed, we found it ranged from five hours to 11 hours 30 minutes.

The RISE app can tell you how much sleep you need
How much sleep RISE users need.

Feel Better on Mounjaro  

While fatigue isn’t listed as a side effect of Mounjaro, some users say the drug makes them feel tired and other side effects can disrupt your sleep. 

Use RISE to get better sleep and more energy while on Mounjaro. The app helps you pay back sleep debt, sync up with your circadian rhythm, and perfect your sleep hygiene.

Users say RISE makes a real difference to their days. 

“It showed me how my late nights add up to sleep debt, which sabotages my energy. Since I've been using RISE, no more afternoon crashes.” Read the review.

And it doesn’t take long — 80% of users feel more energy within five days

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