Where sleep appears in the Mounjaro® labels
Mounjaro® is a once-weekly tirzepatide injection approved in the US for type 2 diabetes and for lowering cardiovascular risk in adults with type 2 diabetes at high risk [1]. Its main safety table lists reactions reported by at least 5% of people on the medicine and more often than on placebo; insomnia is not among them, nor in the postmarketing list [1]. The Medication Guide does not mention sleep as a side effect [2].
The European product information, which also covers weight management, has no sleep-related entry in its table of adverse reactions [3]. The Canadian monograph and its patient information likewise list none [4].
Sleep does come up indirectly. “Trouble sleeping” is one of the symptoms MedlinePlus lists for low blood sugar [9], and the US label warns that combining Mounjaro® with insulin or a sulfonylurea raises the risk of low blood sugar, including severe episodes [1].
| Group | Blood glucose <54 mg/dL | Severe hypoglycemia |
|---|---|---|
| Placebo | 13% | 0% |
| Mounjaro® 5 mg | 16% | 0% |
| Mounjaro® 10 mg | 19% | 2% |
| Mounjaro® 15 mg | 14% | 1% |
What studies of tirzepatide report
An analysis of the FDA Adverse Event Reporting System from 2022 to early 2025 identified 144 statistical signals for tirzepatide, among them “sleep disorder”, which the author linked to low food intake [5]. This type of study counts how often an event is reported alongside a drug; it cannot show that the drug caused the event, and the explanation offered is the author’s interpretation.
A US health-record study followed adults with obesity for up to two years after starting tirzepatide or semaglutide [6]. Among those without type 2 diabetes, tirzepatide was linked to slightly more new insomnia diagnoses than semaglutide (hazard ratio 1.13). The abstract does not report that difference for people with diabetes, the group Mounjaro® is approved for in the US, and the authors note that residual confounding and miscoded diagnoses remain possible.
A matched study of more than 9,000 adolescents with obesity found no significant difference in insomnia between those starting incretin medicines (semaglutide, liraglutide or tirzepatide) and those on lifestyle programmes [7].
Some data point the other way. In SURMOUNT-OSA, two 52-week placebo-controlled trials of tirzepatide in adults with moderate to severe obstructive sleep apnea and obesity, people on tirzepatide reported larger improvements in sleep disturbance and sleep-related impairment than those on placebo, especially if their sleep was poor at the start [8]. In the EU, Mounjaro®’s product information refers to these sleep apnea trials [3].
Possible reasons for broken sleep
Supported by the label: low blood sugar is a documented risk when Mounjaro® is used with insulin or insulin secretagogues such as sulfonylureas [1]. Its warning signs include sweating, shakiness, a fast heartbeat, anxiety and confusion [2], and a low during the night can wake you or leave sleep unsettled [9].
Plausible from label data but not measured for sleep: tirzepatide slows stomach emptying, and reflux and indigestion occurred more often than on placebo in the US trials (reflux 1.7% to 2.5% versus 0.4%) [1]. Lying down with a full stomach can make reflux worse, which may disturb sleep.
Proposed in the literature: the FAERS analysis suggests that reduced intake might underlie some sleep complaints [5]. This has not been tested in a trial.
Other things that disturb sleep
MedlinePlus describes most long-lasting insomnia as secondary, meaning it follows from something else: medical conditions, other medicines, other sleep disorders, or caffeine, tobacco and alcohol [10]. Short bouts often follow stress at work, family pressure or a difficult event. Shift work, travel across time zones, depression and an inactive lifestyle raise the risk [10].
Because people with type 2 diabetes often take several medicines, it is worth asking a pharmacist whether any of them, or any supplements or diet products, can affect sleep; MedlinePlus lists that question among its sleep-habit steps [11].
Steps that help sleep
MedlinePlus’s sleep-habit advice includes waking and going to bed at about the same time, avoiding caffeine and alcohol in the evening, keeping heavy meals away from bedtime, staying active during the day, skipping naps, and getting up for a quiet activity if you cannot fall asleep after about half an hour [11]. A worry journal before bed and relaxation techniques are also on the list [11].
For chronic insomnia, MedlinePlus notes that a form of counselling called cognitive behavioural therapy can ease the anxiety tied to it, that medicines are an option, and that treating an underlying cause matters when there is one [10]. Before taking any sleep aid, ask your prescriber or pharmacist how it fits with your diabetes medicines.
The US label allows Mounjaro® to be taken at any time of day and the weekly day to be changed as long as doses are at least three days apart [1]. No study has looked at whether timing the injection changes sleep, so any change is best agreed with your prescriber.
Mounjaro® is a registered trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Eli Lilly and Company.
When to get help
| Sign | Who to contact | How fast | Source |
|---|---|---|---|
| A person with diabetes who cannot be woken, becomes much less alert or has a seizure | Emergency services | Emergency | MedlinePlus [9] |
| Waking at night sweaty, shaky, with a pounding heart or confused, while using insulin or a sulfonylurea | Check and treat as your care plan says, then tell your prescriber | Today | Medication Guide [2]; MedlinePlus [9] |
| Severe stomach pain that will not settle, possibly spreading to the back | Stop Mounjaro® and call your prescriber right away | Today | Medication Guide [2] |
| Pain, heartburn or discomfort keeping you awake night after night | Your prescriber | At your next appointment | MedlinePlus [11] |
| Sleeping badly for a month or more, low mood, or drowsiness while driving | Your clinician | At your next appointment | MedlinePlus [10][11] |
