What is PMOS, the сondition formerly сalled PCOS?

PMOS vs PCOS: what changed

The condition did not change. Its name did. In May 2026, an international consensus of 56 patient and professional organizations introduced polyendocrine metabolic ovarian syndrome (PMOS) to replace polycystic ovary syndrome, and ASRM endorsed the change. The diagnosis, criteria, and treatments are the same.

The old name pointed at the wrong thing twice. What shows on an ultrasound are multiple small ovarian follicles, not ovarian cysts, and the condition can affect ovulation, metabolism, skin and hair, fertility, and emotional wellbeing, not only the ovaries. Both names will be in use during a three-year transition, so you will see them side by side in records and research.

The four presentations of PMOS

This is the part that explains why two people with the same diagnosis can have almost nothing in common. In adults, diagnosis requires two of three features: ovulatory dysfunction, clinical or biochemical hyperandrogenism, and polycystic ovarian morphology, which is assessed by ultrasound or, in some adults, by an AMH test. Those combinations produce four patterns, described in research as phenotypes A to D.

If your experience does not match the version of the condition you read about, this is usually why.

Common signs

• Periods that are far apart, unpredictable, or missing, often since the teenage years
• Acne that persists past adolescence, or coarse hair growth on the face, chest, or abdomen
• Scalp-hair thinning or increased shedding
• Trouble conceiving, which is often what prompts the first appointment
• Metabolic changes, including insulin resistance. A clinician screens for this with a blood glucose test, usually fasting glucose, HbA1c, or a glucose tolerance test, and repeats it periodically depending on your risk factors.

What causes it

There is no single cause. Insulin resistance, higher androgen levels, and the signals between the brain and the ovaries all interact, and the condition tends to run in families. What is clear is that it is not caused by anything you did.

What PMOS means for fertility

Ovulation is often less frequent and harder to predict, which means fewer chances per year rather than no chance. Many people with PMOS conceive, with or without medical help, and effective options exist when help with ovulation is needed.

Ovulation tests can be harder to read here, because LH patterns can be more variable.

How it is diagnosed

A clinician looks for two of the three features above and rules out other causes, including thyroid disease, high prolactin, and non-classic congenital adrenal hyperplasia. If you have both irregular cycles and signs of high androgens, neither an ultrasound nor an AMH test is required. AMH is not a stand-alone test for PMOS: it can stand in for ultrasound within the criteria, in adults only. In teenagers, both clinical features are needed, and neither ultrasound nor AMH is used.

Five things that are not true

• "You have cysts on your ovaries." What shows on a scan are small immature follicles, not cysts. This misunderstanding is exactly why the name changed.
• "You can't get pregnant." Fertility is affected, not eliminated. Many people conceive naturally, and treatment works well when it is needed.
• "It only affects women in larger bodies." PMOS occurs across body sizes, and people in smaller bodies are often diagnosed later because of this assumption.
• "Regular periods rule it out." Not always. Some people meet the criteria with regular cycles, and regular bleeding does not guarantee that ovulation happens every cycle. A clinician can check if there is reason to.
• "It is only a fertility problem." Metabolic, skin, and mental health effects are part of the condition, which is what the new name is meant to capture.

When to see a doctor

Make an appointment if your periods are more than 35 days apart, you have fewer than eight periods a year, or your cycles stopped being predictable. The same applies to persistent acne, new coarse hair growth, scalp-hair thinning, or difficulty conceiving. A diagnosis opens up treatment for cycles, symptoms, and fertility, and it puts metabolic health on the radar earlier.

Go sooner if androgen-related changes come on quickly, such as rapid hair growth, fast scalp-hair loss, or a deepening voice, or if your periods stop for several months. These can have causes other than PMOS and deserve prompt assessment.

Frequently asked questions