What Is PMOS? Understanding the New Name for PCOS and Why It Matters
Polycystic Ovary Syndrome (PCOS) has officially been renamed Polyendocrine Metabolic Ovarian Syndrome (PMOS). While the diagnostic criteria remain the same for now, the new name better reflects what is actually happening inside the body—and why so many women have struggled to get the answers and treatment they need.
In this video, fertility specialist and board-certified OB-GYN Dr. Natalie Crawford explains why the name change matters, how PMOS develops, and what it means for diagnosis, treatment, fertility, and long-term health.
PCOS is Now PMOS? Fertility Doctor Explains What Changed
Why Did PCOS Become PMOS?
For years, the term Polycystic Ovary Syndrome created confusion.
Many women assumed that ovarian cysts were the primary problem. In reality, the "cysts" seen on ultrasound are actually small follicles containing immature eggs—not dangerous ovarian cysts.
The new name, Polyendocrine Metabolic Ovarian Syndrome (PMOS), highlights the fact that this condition involves:
Hormones throughout the body
Insulin resistance and metabolic health
Communication between the brain and ovaries
Ovulation dysfunction
Fertility and reproductive health
The goal is to shift the focus away from ovarian cysts and toward the underlying metabolic and endocrine factors driving the condition.
What Is Happening in PMOS?
One hallmark of PMOS is a higher-than-average ovarian reserve, meaning the ovaries contain a larger number of eggs.
Because more follicles are recruited each month, ultrasounds often show many small follicles lining the ovaries. This can result in:
High antral follicle count (AFC)
Elevated Anti-Müllerian Hormone (AMH)
Larger ovarian volume
However, these follicles aren't the problem themselves.
The real issue occurs when the brain and ovaries stop communicating efficiently. Chronic inflammation and insulin resistance interfere with normal hormone signaling, making it difficult for a dominant follicle to mature and ovulate.
The Role of Insulin Resistance
One of the most important messages behind the PMOS name change is recognizing the role of insulin resistance.
Insulin is the hormone that helps move glucose from the bloodstream into cells where it can be used for energy.
When cells become resistant to insulin:
The body produces more insulin
Inflammation increases
Weight gain becomes more likely
Hormone production shifts
Ovulation becomes less predictable
High insulin levels can directly affect the ovaries, causing them to produce more androgens (male-type hormones such as testosterone).
This creates a cycle where:
Insulin resistance increases androgen production.
Higher androgen levels worsen metabolic dysfunction.
Ovulation becomes increasingly disrupted.
Common PMOS Symptoms
PMOS symptoms can vary from person to person, but commonly include:
Irregular or Absent Periods
Ovulation may occur infrequently or not at all, leading to irregular menstrual cycles.
Acne
Elevated androgen levels can contribute to persistent acne.
Excess Hair Growth
Some women develop unwanted facial or body hair, known as hirsutism.
Hair Thinning
Others may experience male-pattern hair loss or thinning around the scalp.
Weight Gain and Increased Abdominal Fat
Insulin resistance often promotes visceral fat accumulation around internal organs.
Fertility Challenges
Because ovulation is disrupted, many women with PMOS experience difficulty conceiving.
How Is PMOS Diagnosed?
At this time, PMOS still uses the same diagnostic criteria previously used for PCOS: the Rotterdam Criteria.
A diagnosis requires two of the following three findings:
1. Polycystic Ovarian Appearance
Ultrasound evidence of increased follicle count or ovarian volume.
2. High Androgens
Either:
- Clinical signs such as acne or excess hair growth
- Elevated androgen levels on bloodwork
3. Irregular Ovulation
Irregular menstrual cycles or absent periods.
What May Change in the Future?
One reason many experts support the PMOS name change is the hope that it will eventually expand how clinicians evaluate and treat the condition.
Dr. Crawford points out that metabolic testing is often overlooked despite being central to the disease process.
Important evaluations may include:
- Fasting insulin
- Hemoglobin A1c
- Glucose metabolism assessment
- Comprehensive metabolic screening
As awareness grows, future diagnostic criteria may place greater emphasis on insulin resistance and metabolic health.
PMOS Treatment Options
Treatment should be individualized based on symptoms, fertility goals, and metabolic health.
Potential approaches include:
Lifestyle Interventions
- Nutrition focused on blood sugar regulation
- Exercise
- Sleep optimization
- Stress management
Insulin-Sensitizing Treatments
- Metformin
- Inositol supplementation
GLP-1 Medications
Emerging research suggests GLP-1 receptor agonists may help improve insulin resistance, reduce inflammation, support weight management, and improve ovulation in some patients.
While these medications are not appropriate for everyone, the PMOS framework may help improve awareness and access to treatment options in the future.
Why the PMOS Name Change Matters
The transition from PCOS to PMOS is more than a simple rebrand.
It reflects a growing understanding that this condition is not just about ovarian findings—it is a complex metabolic and endocrine disorder that affects fertility, pregnancy outcomes, long-term health, and quality of life.
By recognizing the role of insulin resistance, inflammation, and hormonal signaling, healthcare providers may be better equipped to diagnose and treat patients earlier and more effectively.
Watch the Full Video
In this video, Dr. Natalie Crawford explains the science behind PMOS, the connection between insulin resistance and hormone health, and why this name change could represent an important shift in how we understand and treat this common condition.