Underlying mechanisms of acupuncture therapy on polycystic ovary syndrome: Evidences from animal and clinical studies

Polycystic Ovary Syndrome (PCOS) represents one of the most common endocrine conditions among women of reproductive age, affecting up to 15% of this population. This complex syndrome manifests through ovulatory dysfunction, hyperandrogenism (elevated levels of male hormones), and polycystic ovaries, frequently accompanied by insulin resistance, obesity, and metabolic alterations. Beyond reproductive symptoms, PCOS is associated with serious complications such as type 2 diabetes, cardiovascular disease, depression, and pregnancy complications. Current standard treatment includes lifestyle changes, oral medications, and surgical interventions, but the efficacy of these approaches is often unsatisfactory.

Medications such as clomiphene may be ineffective in 40% of patients and cause significant adverse effects, while other treatments also present important limitations.

This study aimed to review the potential mechanisms and scientific evidence for the use of acupuncture in the treatment of PCOS, analyzing the most frequently used acupuncture points. The researchers conducted a comprehensive search in three important medical databases (PubMed, Web of Science, and Scopus) from inception through July 2022. Studies in humans and animals investigating the effects of acupuncture in the treatment of PCOS were included, resulting in 62 final publications being analyzed. Of these, 28 were animal studies and 34 were clinical studies in humans.

The methodology followed strict inclusion and exclusion criteria, limiting itself to English-language studies that used traditional acupuncture or electroacupuncture, excluding other techniques such as moxibustion or transcutaneous electrical stimulation.

The results revealed that acupuncture may influence multiple aspects of PCOS through several biological mechanisms. For ovulatory dysfunction, the principal feature of the syndrome, acupuncture has been shown to improve oocyte quality and embryonic development through the regulation of specific signaling pathways. The treatment appears to normalize hormonal imbalances, specifically between follicle-stimulating hormone (FSH) and anti-Müllerian hormone (AMH), which are fundamental to adequate follicular development. Regarding hyperandrogenism, multiple studies have shown that acupuncture can reduce blood testosterone levels, possibly through modulation of the activity of enzymes responsible for the production of male hormones.

For insulin resistance, a central metabolic problem in PCOS, acupuncture has demonstrated improvement in insulin sensitivity through several molecular pathways, including increased expression of glucose transporter proteins and activation of pathways that facilitate glucose metabolism. The treatment has also shown positive effects on body weight reduction and improvement of the lipid profile. In addition, acupuncture appears to benefit the emotional aspects of the syndrome, reducing anxiety and depression through the regulation of neurotransmitters such as serotonin and norepinephrine.

The clinical implications of these findings are promising for patients and health care professionals. Acupuncture emerges as a potentially valuable therapeutic alternative, especially considering its characteristics of low cost, ease of administration, and favorable safety profile. For patients, this represents a treatment option with fewer adverse effects compared with conventional pharmacologic therapies. The evidence suggests that acupuncture may be particularly useful for improving menstrual regularity, reducing symptoms of anxiety and depression, and aiding metabolic control.

The most frequently used acupuncture points were SP-6 (Sanyinjiao) and ST-29 (Guilai), with the majority of points located in the abdomen and extremities. For health care professionals, these results provide a scientific basis for considering acupuncture as complementary therapy in the integrated management of PCOS, especially in cases where conventional treatments are not fully effective or well tolerated.

However, the study acknowledges important limitations that should be considered. There is considerable heterogeneity among the studies analyzed in terms of animal models used, acupuncture protocols (point selection, frequency, electrical intensity), and main outcomes assessed. Most studies were conducted in different PCOS phenotypes, and although the pathophysiology is similar, there may be differences that limit the universal applicability of the results. In addition, many studies presented methodological limitations, including small sample sizes and variable methodological quality.

Despite the promising evidence, more high-quality randomized clinical trials are still needed to definitively establish the efficacy of acupuncture in PCOS. The exact mechanisms by which acupuncture exerts its effects are still not fully understood, and future research using advanced technologies such as transcriptomic analysis may provide deeper insights. In conclusion, although acupuncture shows significant potential as complementary treatment for PCOS, more research is needed to standardize treatment protocols and confirm its long-term efficacy, allowing its broader integration into evidence-based clinical practice.