May 12, 2026 – Polycystic ovary syndrome (PCOS), a condition affecting approximately 1 in 8 women and more than 170 million people worldwide,1 has been renamed Polyendocrine Metabolic Ovarian Syndrome (PMOS) following a landmark global consensus process published in The Lancet.2

The new name was chosen to more accurately reflect the condition’s complex endocrine, metabolic, and ovarian features, while removing the misleading implication that the condition is primarily defined by ovarian “cysts.” The name change follows years of international work and a global consensus process involving patients, clinicians, researchers, and professional organizations across world regions. For many patients, the older term “PCOS” has contributed to confusion, delayed diagnosis, fragmented care, and a narrow focus on ovarian appearance rather than the broader hormonal and metabolic disturbances that often drive symptoms and long-term health risks. For those interested in the condition’s naming journey, this is not the first name change – it was first known as Stein-Leventhal syndrome3 after the two physicians in the 1930’s who described it, before later becoming known as polycystic ovary syndrome.

RRM Clinician with a PMOS patient

Restorative reproductive medicine has long recognized that not all “PCOS” is the same and that the ovarian cystic part is misleading, even though it can and present in patients in which the endocrine abnormalities are the key feature.

Clinicians emphasize the importance of identifying the underlying physiologic drivers behind polycystic ovarian morphology and ovulatory dysfunction — rather than treating all patients as though they share one uniform disease process. While some patients primarily present with ovulatory dysfunction and ovarian morphology changes, others show insulin resistance, metabolic dysfunction, hyperandrogenism, inflammatory contributors, adrenal or hypothalamic factors, environmental influences, or overlapping endocrine disturbances.

PMOS also has an important familial and genetic dimension. Research suggests that PMOS often clusters in families, and genetic studies support a complex inherited susceptibility rather than a single-gene cause. This susceptibility appears to involve hormonal, metabolic, neuroendocrine, and ovarian pathways, helping explain why symptoms and risk profiles can vary widely between patients.2,4

Family studies also suggest that relatives of affected women — including sisters, mothers, fathers, and brothers — may show related metabolic or hormonal traits. In male relatives, research has found higher rates of features such as insulin resistance, dyslipidemia, cardiometabolic risk, and androgen-related patterns. Some researchers refer to this as a possible “male PCOS phenotype,” but this remains an evolving research concept rather than a formal diagnosis of “male PMOS.” 5,6

The growing shift toward distinguishing PMOS (Polyendocrine Metabolic Ovarian Syndrome) from broader hyperandrogenic or metabolic PCOS presentations reflects what many RRM physicians have observed clinically for decades:

  • Some patients primarily demonstrate ovarian morphology changes
  • Others primarily exhibit insulin resistance and metabolic dysfunction
  • Others have inflammatory, hypothalamic, adrenal, environmental, or endocrine contributors
  • Many patients overlap, but not all belong in the same category

This evolving terminology is an important step toward more precise, patient-centred reproductive medicine.

RRM has consistently advocated for:

  • individualized diagnosis
  • cycle-based evaluation
  • endocrine and metabolic investigation
  • identification of root contributors
  • restoration of normal reproductive physiology whenever possible

The Lancet includes a managed three-year transition period, with coordinated updates planned across clinical guidelines, research systems, education, electronic health records, health policy, and disease classification systems. The new terminology is expected to be incorporated into the next International Guideline update in 2028. Monash University has prepared a collection of resources and videos for download: https://bit.ly/3V85nPJ.7 These materials include patient and healthcare professional resources, with translations available in English, Arabic, Persian, Mandarin, German, Spanish, Portuguese, French, and other languages.

While a terminology change is an important first step, it cannot be the final step. To improve care and reduce stigma, the broader medical community will need to translate this change into improved clinical education, patient communication, research, and more individualized management. Moving beyond a “one-size-fits-all” label is good for patients, good for science, and good for reproductive medicine. We welcome continued refinement in the understanding and classification of these conditions as reproductive endocrinology advances.

References:

  1. Neven, ACH, Forslund, M, Ranasinha, S, et al.Prevalence of polycystic ovary syndrome: a global and regional systematic review and meta-analysis. Hum Reprod Update. 2026; published online Jan 13. https://doi.org/10.1093/humupd/dmaf030
  2. Teede HJ et al. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. Lancet. 2026;DOI:10.1016/S0140-6736(26)00717-8.
  3. STEIN IF Sr. The Stein-Leventhal syndrome; a curable form of sterility. N Engl J Med. 1958 Aug 28;259(9):420-3. doi: 10.1056/NEJM195808282590904. PMID: 13578075.
  4. Moolhuijsen, L.M.E., Zhu, J., Mullin, B.H. et al. Genomic analyses implicate hormonal and metabolic dysregulation in polycystic ovary syndrome. Nat Genet (2026). https://doi.org/10.1038/s41588-026-02543-9
  5. Jafarabady K, Mohammadi I, Firouzabadi SR, Mohammadifard F, Soltani SM, Paksaz A, Noroozzadeh M, Ramezani Tehrani F. Male polycystic ovarian syndrome phenotype: a meta-analysis of endocrine-metabolic dysregulation in fathers and brothers of PCOS-affected women. Basic Clin Androl. 2025 Nov 16;35(1):44. doi: 10.1186/s12610-025-00290-1. PMID: 41243102; PMCID: PMC12621411.
  6. Di Guardo F, Ciotta L, Monteleone M, Palumbo M. Male Equivalent Polycystic Ovarian Syndrome: Hormonal, Metabolic, and Clinical Aspects. Int J Fertil Steril. 2020 Jul;14(2):79-83. doi: 10.22074/ijfs.2020.6092. Epub 2020 Jul 15. PMID: 32681618; PMCID: PMC7382675.
  7. PMOS Resources – MCHRI [Internet]. MCHRI. 2026 [cited 2026 May 29]. Available from: https://www.mchri.org.au/guidelines-resources/community/pmos-resources-2/