Beyond acne and irregular periods, the hidden side of PMOS

Acne, facial hair, hair growth in unexpected areas or, conversely, unexplained hair loss and… all too often, irregular periods. During adolescence, it can be difficult to know what is “normal.” Yet behind these seemingly minor concerns may lie a syndrome that is still poorly understood: polyendocrine metabolic ovarian syndrome (PMOS).

For decades, it was known as polycystic ovary syndrome, a name that reduced this complex condition to the presence of follicles or cysts detected on the ovaries. Since May 2026, however, the syndrome has been given a new name, reflecting a better understanding of its causes.

Indeed, the exact cause of the syndrome has yet to be fully understood. However, research increasingly points to “a broader metabolic disorder linked to insulin resistance,” explains Mary Chammas, associate professor of Clinical Obstetrics and Gynecology. “The condition is not limited to the ovaries,” she adds.

When the body’s cells become less responsive to insulin, the pancreas compensates by producing more of the hormone. This, in turn, stimulates the ovaries to produce more androgens – hormones typically associated with male physiology – which can lead to excess hair growth in unwanted areas.

“Insulin resistance is hereditary and is linked to a number of other conditions, including diabetes, cardiovascular disease, high blood pressure and high cholesterol,” Chammas points out. “A healthy lifestyle can delay the onset of symptoms or conditions associated with insulin resistance, such as diabetes or, in the case of PMOS, irregular periods, but it cannot eliminate the resistance itself. It is still there.”

A major health issue

According to the World Health Organization, PMOS affects an estimated 10-13% of women of reproductive age. An estimated 70% of women with PMOS worldwide are unaware that they have the condition. In the Eastern Mediterranean region, the prevalence is higher, at 15.1%.

Symptoms of PMOS can begin as early as puberty, with menstrual irregularities being one of the key signs. “The most common issue is a delayed menstrual cycle, which can stretch to 40 days instead of the usual 28 to 30,” Chammas explains. “In some cases, periods may stop altogether without medical treatment.”

Other symptoms include severe, “persistent and recurrent” acne, “excess hair growth on the face and in unusual areas of the body, such as the chest and back,” or, conversely, “scalp hair loss.” “All of these symptoms are manifestations of elevated testosterone levels,” she says.

These symptoms can lead girls as young as 15 or 16 to seek gynecological care. “By that age, menstrual cycles should be becoming more regular, and the acne associated with puberty should have started to subside,” Chammas stresses. “In some cases, we wait until the age of 18 before making a definitive diagnosis.”

A diagnosis is made when a young woman meets two of three criteria: ovulatory dysfunction, with delayed periods, hyperandrogenism (elevated levels of male hormones, including testosterone), and/or excessive acne or hair growth, an ultrasound finding of polycystic ovaries. The diagnostic process combines a clinical examination, blood tests performed on the third day of the menstrual cycle to assess androgen levels, and a pelvic ultrasound to examine the ovaries, including whether they have at least 20 follicles each or an increased volume.

A chronic syndrome

Over the long term, prolonged absence of periods “can increase the risk of endometrial and uterine cancer because the patient is continuously exposed to estrogen but does not ovulate, meaning that progesterone is not produced to protect the endometrium.” This is why it is important to induce menstrual bleeding periodically.

PMOS is also the leading cause of infertility worldwide, affecting an estimated 8-12% of women of reproductive age, according to the 2016 study Fertility and Infertility: Definition and Epidemiology, published by the Canadian Society of Clinical Chemists. It is also responsible for 70-80% of cases of anovulatory infertility, according to the American Society for Reproductive Medicine.

A PMOS diagnosis can be particularly difficult on a personal and psychological level. “Our patients are young, usually in their twenties,” Chammas says. “At that age, they are full of life. Being told that they have a chronic condition with no cure can be frightening. I try to reassure them and explain that we can manage the condition’s negative effects and that they can still lead a normal life.”

Listen to your body

Treatment depends on the patient and may include medication to address excess weight – although not all patients are overweight – acne, or to regulate menstrual cycles. Lifestyle changes can also help manage insulin resistance. Regular exercise, a healthy diet and getting enough sleep can all play a role.

For Chammas, the key is to stay vigilant and keep track of one’s menstrual cycle, which typically lasts around 28 days. If a period is more than a week late, it is worth consulting a doctor. Women should also pay attention to any increase in hair growth and be aware of their family history: having relatives with diabetes or cardiovascular disease may indicate a predisposition to insulin resistance.

Research into PMOS has also gained momentum. For years, women’s health conditions received far less attention, leaving major gaps in knowledge. That is now changing, as more women are entering the field of research and these conditions receive greater attention. A better understanding of insulin resistance is also opening the door to new treatments and renewed hope for patients.