The condition long known as PCOS has officially been renamed Polyendocrine Metabolic Ovarian Syndrome, or PMOS, reflecting what many metabolic-health clinicians have known for years.
For decades, women diagnosed with polycystic ovary syndrome, or PCOS, were given a name that never quite matched the condition. In this old paradigm, women who struggled with obtaining regular menstrual cycles or fertility were simply told they had cysts on their ovaries and that their hormones were abnormal. The go-to medication was birth control only to help regulate cycles, and the go-to advice was “lose weight.”
Now, that is beginning to change.
A new article published in The Lancet has officially introduced a new name for PCOS: Polyendocrine Metabolic Ovarian Syndrome, or PMOS. The change was supported by a major international effort involving more than 50 patient and professional organizations, more than 22,000 survey responses, and years of work by experts and patients around the world.
At Toward Health, we welcome this change because the condition was never simply about ovarian cysts. The new name better reflects what PMOS truly is: a complex metabolic and hormonal condition. Research shows that approximately 85% of individuals with PMOS have insulin resistance and hyperinsulinemia, including up to 75% of lean individuals.
Why the old name was a problem
The term polycystic ovary syndrome suggested that the defining problem was the presence of ovarian cysts. However, many women with this condition do not have true ovarian cysts. The “cysts” described on ultrasound are usually small follicles, not pathologic cysts. Even more importantly, focusing only on the ovaries can distract from the broader endocrine and metabolic dysfunction that drives many of the symptoms. In fact, the Endocrine Society’s announcement described the old name as reducing a complex, long-term hormonal disorder to a misunderstanding about “cysts” and ovaries, which contributed to missed diagnoses and inadequate care.
The names of conditions matter as they shape how clinicians acts, how patients think, and how research is funded. Shifting from the anatomical finding of cysts to the hormonal environment of insulin resistance is the correct framing for this condition.
The new name: PMOS
The new name is Polyendocrine Metabolic Ovarian Syndrome.
Polyendocrine acknowledges that more than one hormonal system can be involved.
Metabolic acknowledges the central role of insulin resistance, weight regulation, glucose metabolism, and cardiometabolic risk.
Ovarian preserves the reproductive and ovulatory features of the condition without implying that ovarian cysts are the main cause.
PMOS is described as a condition characterized by hormonal fluctuations with effects on weight, metabolic health, mental health, skin, and the reproductive system. It affects about 1 in 8 women, or more than 170 million women worldwide.
This new name does not mean every person with PMOS has the same presentation; some are lean, some struggle with weight, some have obvious androgen symptoms, and some primarily present with infertility or irregular cycles.
But the name finally points clinicians toward the bigger picture: it is a whole-body endocrine-metabolic condition.
Low-carb clinicians were early to this conversation
In 2005, Dr. Eric Westman and colleagues published a pilot study evaluating a low-carbohydrate ketogenic diet in women with obesity and PCOS.
The study was small but the findings were striking. Participants were instructed to limit carbohydrate intake to 20 grams or less per day for 24 weeks. Among the five women who completed the study, there were significant reductions in body weight, percent free testosterone, LH/FSH ratio, and fasting insulin. Two women became pregnant despite prior infertility problems.
For years, many clinicians in the low-carb and metabolic-health community have warned patients that if they had been struggling with infertility related to PCOS/PMOS, improving insulin resistance and restoring ovulation could make pregnancy possible, sometimes sooner than expected!
At Toward Health, we have always viewed hormone health and metabolic health as deeply connected. PMOS is one of the clearest examples of why that approach matters.
The right framework
PMOS requires a broader, more personalized approach that may include:
- Careful evaluation of menstrual patterns, ovulation, and androgen symptoms
- Laboratory assessment, including metabolic markers
- Screening for insulin resistance, prediabetes, type 2 diabetes, lipids, blood pressure, fatty liver risk, sleep apnea, and cardiometabolic risk
- Nutrition strategies that improve insulin sensitivity and are sustainable for the individual
- Resistance training and movement to support glucose disposal and muscle health
- Sleep and stress support
- Fertility planning and pregnancy prevention counseling when ovulation may return
For some patients, a lower-carbohydrate approach can be powerful. The key is that care should be individualized, evidence-informed, and rooted in the understanding that PMOS is a complex condition with metabolic, endocrine, reproductive, and psychological components.
At Toward Health, that is exactly how we approach care.
