If [obstructive] sleep apnea is primarily caused by obesity, the weight loss & anti inflammatory effect of GLP-1/GIP agonists like Tizepatide are proven to reduce it:
"Tirzepatide effectively reduces the severity of obstructive sleep apnea in patients with obesity by significantly lowering the apnea-hypopnea index and promoting weight loss. These effects, along with improvements in other health markers, suggest that tirzepatide could be a valuable treatment option for managing OSA in obese individuals."
Among persons with moderate-to-severe obstructive sleep apnea and obesity, tirzepatide reduced the AHI, body weight, hypoxic burden, hsCRP concentration, and systolic blood pressure and improved sleep-related patient-reported outcomes. (Funded by Eli Lilly; SURMOUNT-OSA ClinicalTrials.gov...
pubmed.ncbi.nlm.nih.gov
> Atul Malhotra et al. "Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity.."
The New England journal of medicine (2024).
https://doi.org/10.1056/nejmoa2404881.
> et al. "Tirzepatide reduces sleep events in patients with sleep apnea and obesity."
The Brown University Psychopharmacology Update (2024).
https://doi.org/10.1002/pu.31214.
Anectodaly, growth hormone-releasing hormones & peptides (GHRH/P), like Tesamorelin, are known to improve slow wave sleep, but as far as I understand the literature evidence is sparse:
"Tesamorelin is a growth hormone-releasing hormone analog primarily studied for its effects on non-alcoholic fatty liver disease in individuals with HIV. While the primary focus of research has been on its impact on liver fat and histology, there is limited direct information available regarding its effects on sleep, particularly deep sleep."
My personal experience suggests that Tesamorelin/Ipamorelin administration before sleep, definitely makes me sleepy and have a subjective impact on the kind of sleep I experience. However, my sleep analysis data did not really express any more frequent or longer phases of slow wave sleep; I was rather more prone to dehydration (as they cause water retention) and have experienced higher RHR (probably due to dehydration). As an indirect maybe positive side effect, nocturia will improve and so may one's sleep quality.