What the labels and official product information say
Each adverse reaction table only shows reactions that passed a set threshold and were more frequent than on placebo. The Wegovy®, Zepbound® and Saxenda® adult tables use a 2% cut-off; the Mounjaro® and Foundayo™ tables use 5% [1][4][5][6][7]. A reaction missing from a table is therefore not proven never to happen.
- The Saxenda® gap is under one percentage point. The same table lists anxiety at 2.0% against 1.6% [1].
- The Trulicity® figures show no consistent excess over placebo or other diabetes medicines [3].
- No label describes what the insomnia was like or how long it lasted, apart from the EU note on Saxenda® timing [2].
| Document and trial pool | Medicine | Comparison |
|---|---|---|
| Saxenda®, US label, adult weight trials (table cut-off 2%) [1] | 2.4% | Placebo 1.7% |
| Saxenda®, EU product information, section 4.8 [2] | Common, mainly in the first 3 months | — |
| Trulicity®, Canadian monograph, placebo-controlled trials, 26 weeks [3] | 0.7% (0.75 mg), 1.7% (1.5 mg) | Placebo 1.2% |
| Trulicity®, Canadian monograph, all trials up to 104 weeks [3] | 0.7% (0.75 mg), 1.6% (1.5 mg) | Other diabetes medicines 1.5% |
| Zepbound®, Wegovy® (2.4 mg and 7.2 mg), Mounjaro®, Foundayo™, US labels [4][5][6][7] | Not in the tables | — |
Sleep apnea: a different kind of sleep question
In the US, Zepbound® has an approval for obstructive sleep apnea of moderate or severe degree in adults who have obesity, alongside diet and activity [4]. In its two 52-week trials, the apnea-hypopnea index, a count of breathing pauses per hour, fell by about 25 and 29 events an hour on tirzepatide against about 5 on placebo, and sleep-related impairment improved on a patient questionnaire [4]. In the EU, the Mounjaro® information reports the same trials in its clinical results section [8], and the Saxenda® information describes a 32-week liraglutide trial in sleep apnea [2].
These are results for a diagnosed condition, not a promise of better sleep for everyone. The Zepbound® sleep apnea article covers the trials in detail.
What other studies report
Research on ordinary sleep quality, as opposed to sleep apnea, is thin. One prospective study from Turkey followed 78 adults with obesity who started semaglutide or tirzepatide. On a standard sleep quality questionnaire, the share with poor sleep fell from about 55% to about 17% after three months, and sleep improvement went along with improvement in depressive symptoms rather than with the amount of weight lost [9].
The study had no comparison group, so it cannot separate a medicine effect from the effects of starting treatment, changing habits or simply being followed. It does suggest that, for many people, sleep does not get worse on these medicines.
Why sleep may change
- Supported by the labels: stomach reactions are common and can be felt at night. In the Zepbound® weight trials, nausea was reported by 25% to 29% against 8% on placebo, vomiting by 8% to 13% against 2%, and reflux by 4% to 5% against 2% [4].
- Supported by the labels: in people with diabetes who also use insulin or a sulfonylurea, low blood sugar is more likely. Signs listed in the Saxenda® Medication Guide include sweating, shakiness, a fast heartbeat, headache, confusion and drowsiness, which can wake a person from sleep [1].
- Supported by the labels: insomnia itself, on liraglutide, at a small excess over placebo [1][2].
- Proposed but not tested in trials: in the Turkish study, sleep tracked mood more closely than weight [9]. Whether mood changes explain sleep changes on GLP-1 medicines has not been studied directly.
- General knowledge: caffeine late in the day, irregular bedtimes, screens in bed, stress and night-time urination are frequent causes of poor sleep [10][11].
Other causes of poor sleep
MedlinePlus lists habits and environment, such as noise, light and changing bedtimes, alongside medicines and substances, including too much caffeine and some cold medicines and diet pills [10]. Depression, anxiety, acid reflux, allergies, thyroid problems and pain can all keep people awake [10]. NHLBI adds shift work, travel across time zones, little daytime activity, alcohol and nicotine, and hormone changes in pregnancy and menopause [11].
Many of these overlap with the first months on a GLP-1 medicine: a new routine, worry about side effects, and changes in when and how much you eat. Daytime tiredness is a separate entry in the labels, at 5% to 7% on Zepbound® against 3% on placebo, and the fatigue article covers it [4].
What may help
NHLBI describes habits that support sleep: a regular sleep and wake schedule, avoiding caffeine, nicotine and alcohol close to bedtime, regular daytime activity, eating meals at regular times without a late dinner, and drinking less just before bed [12]. For long-lasting insomnia, it names cognitive behavioural therapy for insomnia (CBT-I) as the usual first treatment [12].
If reflux or nausea wakes you, the reflux and nausea articles describe what the labels and health agencies suggest. Talk to a clinician before taking sleep aids: NHLBI says antihistamine sleep products can be unsafe for some people and that melatonin has not been proven to treat insomnia [12]. GLP-1 medicines slow stomach emptying, which can change how other tablets are absorbed, so a pharmacist should check any new product [4]. Do not change your GLP-1 dose or its timing on your own.
Where the related topics are covered
Brand pages such as Mounjaro® and insomnia, Zepbound® and insomnia and Saxenda® and insomnia go through each label. How many hours adults need and how to log sleep and water sit on the sleep and hydration page.
Saxenda®, Wegovy®, Ozempic® and Rybelsus® are registered trademarks of Novo Nordisk A/S. Mounjaro®, Zepbound® and Trulicity® are registered trademarks of Eli Lilly and Company; Foundayo™ is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.
When to get help
The signs and contact information below come from this article’s sourced guidance.
Emergency
- In diabetes on insulin or a sulfonylurea: confusion, fainting or being very hard to wake
Contact: Emergency care
- Waking with severe stomach pain that does not ease, with or without vomiting
Contact: Stop the medicine and call your provider right away