Sleep and endocrine effects of acupuncture for insomnia: a systematic review and meta-analysis of randomized controlled trials

Background: Insomnia, a prevalent sleep disorder linked to endocrine dysfunction, severely impairs quality of life. Acupuncture has been widely applied for its management, but evidence on its impact on sleep outcomes and endocrine regulation remains uncertain. Methods: Randomized controlled trials (RCTs) published until August 13, 2025, were explored in the subsequent databases: PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang. Two reviewers independently screened studies, extracted data, and assessed risk of bias with RoB 2. Eligible trials enrolled insomnia patients receiving acupuncture or combined therapy versus sham acupuncture or medication. Outcomes included sleep-related scales, polysomnographic measures, and endocrine indicators. Meta-analysis was conducted using RevMan 5.4. Results: = 0%). Salivary melatonin did not differ between groups, whereas salivary cortisol was lower in the acupuncture group (MD = 0.05, 95% CI: 0.02 to 0.08). Acupuncture reduced PSQI scores (MD = 3.39, 95% CI: 4.20 to 2.59). ISI improved in sham controlled trials (MD = 1.82, 95% CI: 2.95 to 0.68) but not in medication controlled comparisons. Polysomnography indicated improved sleep efficiency (MD = 6.40, 95% CI: 4.93 to 7.86) and overall improvements in total sleep time, sleep onset latency, and wake after sleep onset, with subgroup patterns suggesting contributions from treatment intensity and clinical subtype. Conclusion: This study suggests that acupuncture significantly improves subjective sleep quality, while also modulating melatonin and cortisol levels, highlighting its potential role in sleep and endocrine regulation. Systematic review registration: PROSPERO registration number is provided as CRD420251125885.