PCOS Is Now Called PMOS: What It Means for Your Cycle

PMOS

PCOS just got a new name. It is now calle PMOS.

As of May 12, 2026, polycystic ovary syndrome (PCOS) has officially been renamed polyendocrine metabolic ovarian syndrome (PMOS). The change was published in 'The Lancet' following a 14-year global consensus process involving over 50 professional and patient organizations and more than 22,000 voices worldwide.

If you have been diagnosed with PCOS, your condition has not changed. The name has.

Why PCOS Was Renamed to PMOS

The old name was scientifically inaccurate in two important ways.

First, it implied that ovarian cysts are the defining feature of the condition. They are not. Research confirmed there is no increase in abnormal ovarian cysts in the condition; the structures seen on ultrasound are arrested follicles, not pathological cysts. Many people with PMOS do not have cysts at all, and went undiagnosed for years because of it. The WHO estimates that 70% of people with the condition are currently undiagnosed.

Second, the name focused attention on the ovaries as the root cause, while ignoring the endocrine and metabolic dimensions that actually drive the condition.

The new name reflects what the science shows: "Polyendocrine" captures the multi-hormonal nature. "Metabolic" names the core mechanism. "Ovarian" retains the connection to reproductive health, as one part of a larger picture.

What Is PMOS (Formerly PCOS)?

PMOS is a complex hormonal and metabolic condition that affects the whole body. At its core, most people with PMOS have insulin resistance: the body produces too much insulin, which triggers excess androgen production and disrupts ovulation. This is why PMOS reaches far beyond irregular periods and is linked to increased diabetes risk, cardiovascular disease, infertility, weight, skin, and mental health.

PMOS Symptoms and Diagnosis Criteria

PMOS is diagnosed when at least 2 of the following 3 criteria are met: 1. Irregular ovulation or periods 2. Elevated androgen levels (clinical or biochemical) 3. Polycystic-appearing ovaries on ultrasound (or elevated Anti-Müllerian Hormone (AMH) in adults)

Note: polycystic ovaries are not required for a diagnosis, and never were. AMH can now officially replace the ultrasound criterion in many adult cases under the new framework.

Common symptoms include irregular or absent periods, acne, unwanted hair growth, weight changes, and mental health challenges such as anxiety or depression, now officially recognized as core features of PMOS.

What PMOS Means for Your Cycle

PMOS often results in irregular, long, or anovulatory cycles. Ovulation may be delayed, infrequent, or absent in some cycles. This variability is important to understand when tracking your cycle, because it affects when and whether a temperature shift occurs.

For Daysy to identify ovulation, your basal body temperature must rise characteristically to a new, sustained higher baseline. In cycles where ovulation does not occur, this shift will not happen; Daysy will show significantly more red and yellow days as a result. This is not a limitation of the device; it is the algorithm working correctly. Daysy shows green only after confirming that ovulation has taken place.

Can You Use Daysy with PMOS?

Daysy is a cycle tracker for determining ovulation and the fertile and non-fertile days in the cycle. It is not a contraceptive.

Many women with PMOS use Daysy effectively. Daysy can support you if your cycles fall within the 19 to 40 day range, including occasional cycles that exceed this range. If your cycle regularly falls outside the 19 to 40 day range, Daysy is not recommended.

What Daysy offers you with PMOS:

Cycle visualization. The DaysyDay app displays your personal cycle statistics, including when ovulation occurred, your cycle length, and your average temperature step over time. This gives you and your healthcare provider a clear picture of your cycle patterns.
Anovulatory cycle recognition. In cycles where no ovulation occurs, Daysy will not show green. This makes anovulatory cycles visible; useful information when working with a doctor or specialist.
Long-term pattern tracking. Because PMOS cycles can vary significantly from one cycle to the next, tracking over multiple cycles is particularly valuable. Daysy stores your data and builds a picture of your individual cycle over time.

Please note that ovulation prediction may have more variance due to cycle irregularity. Daysy's algorithm adapts to your individual data over time, but irregular cycles require more data to establish patterns.

Learn more on DaysyDay App

Influencing Factors on the Cycle

PMOS vs PCOS: What Stays the Same

The transition from PCOS to PMOS will take place over three years across medical records, clinical guidelines, research publications, and patient resources. During this period, you may encounter both names. The recommended phrasing is PMOS (formerly PCOS).

Your diagnosis, your diagnostic criteria, and your treatment options remain unchanged. What changes is the framework, and with it, the expectation that the metabolic dimension of this condition is taken seriously from the start.

Learn more

Find out everything about polycystic ovary syndrome (PCOS): symptoms, diagnosis, treatment, and how cycle tracking can support women with PCOS.

PCOS

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Hormonal Influence

Learn when menstrual irregularities are a cause for concern and when it’s time to consult a doctor. Discover key signs of cycle disturbances — from missed periods to heavy bleeding.

Cycle Disorders

Sources

Teede HJ et al. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. The Lancet. Published online May 12, 2026. DOI: 10.1016/S0140-6736(26)00717-8

Endocrine Society. PMOS official statement. May 12, 2026. endocrine.org

van de Roemer et al. 2021. Performance study, 107,020 cycles.