What is the difference between PCOS and PMOS?

Bottom lineThere is no difference - PMOS (polyendocrine metabolic ovarian syndrome) is simply the new name given to PCOS in May 2026 after an 11-year global consultation; the diagnosis criteria, treatments, and the condition itself are exactly the same, and both names will coexist for years.

There is no medical difference - PMOS is the new name for PCOS. In May 2026, polycystic ovary syndrome (PCOS) was officially renamed polyendocrine metabolic ovarian syndrome (PMOS). Same condition, same diagnosis, same treatments - only the label changed.

Same condition, new name

The renaming was announced on May 12, 2026, in a paper published in The Lancet and presented at the European Congress of Endocrinology in Prague. It capped an 11-year process that consulted around 22,000 patients, clinicians, and researchers worldwide - the most extensive disease renaming in modern medicine.

Why the name changed

The old name misled on two fronts:

• The "cysts" in PCOS are not cysts - they are normal immature follicles, and not everyone with the condition has them. Some people were wrongly told they "didn't have PCOS" after a normal ultrasound.
• Calling it an ovary syndrome framed a whole-body hormonal and metabolic condition as a gynecology-only problem, which contributed to under-diagnosis and fragmented care.

PMOS names what the condition actually is: multiple hormone systems (polyendocrine), metabolic effects like insulin resistance and diabetes risk (metabolic), with the ovaries as one key site rather than the whole story.

What stays exactly the same

• Diagnosis: the same criteria apply (irregular cycles, signs of higher androgens, polycystic-appearing ovaries - usually 2 of 3), per the 2023 international guideline
• Treatment: lifestyle changes, metformin, combined pills, anti-androgens, and fertility treatment where relevant are all unchanged
• Your records: nothing needs reissuing; an existing PCOS diagnosis simply is a PMOS diagnosis

Which name will you hear?

Both, for years. Clinicians, websites, and records will transition gradually, so searching or discussing either name refers to the identical condition.

Related: PCOS renamed to PMOS: the full story · what is PMOS