Acupuncture in Polycystic Ovary Syndrome: A Narrative Review of Neuroendocrine-Immune Evidence, Reproductive Outcomes, and Evidence Gaps.

Polycystic ovary syndrome (PCOS) is a heterogeneous reproductive, endocrine, and metabolic disorder in which autonomic, neuroendocrine, inflammatory, and metabolic abnormalities may converge on ovarian and endometrial function. This narrative review evaluates evidence relevant to acupuncture in PCOS, with emphasis on evidence source, directness, and clinically meaningful reproductive outcomes. PubMed, Embase, and Web of Science were searched from inception to March 31, 2026, supplemented by backward citation tracking. We prioritized human PCOS trials and mechanistic studies, followed by PCOS-specific preclinical evidence; findings from other conditions were included only as explicitly labeled indirect evidence. No formal risk-of-bias assessment or meta-analysis was undertaken. Clinical evidence most consistently suggests possible effects on menstrual or ovulatory function, sympathetic activity, and insulin resistance, although results vary across protocols and PCOS phenotypes. Evidence for pregnancy, ongoing pregnancy, embryo quality, and live birth remains limited and inconsistent, and acupuncture has not been established as a substitute for guideline-based fertility treatment. Human data directly linking acupuncture to immune-cell reprogramming, endometrial immune tolerance, or correction of window-of-implantation timing are scarce. PCOS-specific animal studies provide plausible signals involving hypothalamic-pituitary-ovarian regulation, ovarian sympathetic signaling, inflammatory pathways, oxidative stress, and insulin signaling, but these findings cannot be assumed to translate to clinical reproductive benefit. Overall, the neuroendocrine-immune framework is best viewed as a hypothesis-guiding map that distinguishes relatively supported clinical domains from preclinical and indirect mechanisms. Future trials should combine standardized acupuncture protocols with phenotype stratification, prespecified ovulation, ongoing-pregnancy, and live-birth outcomes, and longitudinal autonomic, metabolic, inflammatory, ovarian, and endometrial measurements.