In May 2026, after more than a decade of global consensus work, polycystic ovary syndrome (PCOS) was officially renamed polyendocrine metabolic ovarian syndrome (PMOS). The change was published in The Lancet and developed with 56 academic, clinical, and patient organizations, including the Endocrine Society. The old name was inaccurate. The condition is not fundamentally about ovarian cysts, and it is not primarily gynecological. It is a multisystem endocrine and metabolic disorder in which insulin resistance is the central driver for most patients.
Gold-standard clamp studies found insulin resistance in 75 percent of lean women and 95 percent of women with overweight who carry the diagnosis, and a meta-analysis of clamp studies found insulin sensitivity reduced by roughly 27 percent independent of BMI. That single mechanistic fact reorganizes the entire treatment plan. Address the hyperinsulinemia, and androgen excess, cycle irregularity, acne, hair loss, weight resistance, and long-term cardiometabolic risk tend to move together.
At Portland Clinic of Natural Health, Dr. Maria Reebs, DNP, evaluates and treats PMOS as the metabolic condition it is, combining comprehensive laboratory phenotyping with nutrition, exercise physiology, targeted supplementation, and medication where appropriate.
On May 12, 2026, The Lancet published the outcome of one of the most extensive disease-renaming efforts in modern medicine. Polycystic ovary syndrome became polyendocrine metabolic ovarian syndrome, or PMOS.
This was not a branding exercise. The process was led by Professor Helena Teede at Monash University, with international co-leads including Professor Terhi Piltonen of the University of Oulu and Professor Anuja Dokras of the University of Pennsylvania, working through the Androgen Excess and PCOS Society and the patient organization Verity. Governance involved 56 leading academic, clinical, and patient organizations. The evidence base included iterative global surveys drawing responses from 14,360 people with the condition and multidisciplinary health professionals across all world regions, along with modified Delphi methods, nominal group technique workshops, and formal implementation analysis.
The consensus group prioritized scientific accuracy over preserving the familiar acronym, and chose an implementation approach they describe as evolution rather than transformation. A co-designed global rollout is under way, including a transition period, education, and alignment with health systems and disease classification.
If you were diagnosed with PCOS, your diagnosis is still valid. Nothing in your chart changed on May 12. What changed is the framing, and the framing was doing real damage.
The term originated from a surgical observation nearly a century ago: what appeared to be small sacs on the ovaries of a woman who also had elevated androgens and difficulty conceiving. Those structures were never actually cysts. They are immature follicles arrested in development, a consequence of the hormonal environment rather than its cause. A companion paper from the same group found no increase in abnormal ovarian cysts in the condition, which strengthened the case for the change.
Three problems followed from the misnaming, and any clinician who treats this condition has watched all three play out.
Patients without visible ovarian findings were dismissed. Because the name promised cysts, clinicians looked for cysts. A woman with irregular cycles, hirsutism, acne, and textbook hyperinsulinemia could be told she did not have the condition because her ultrasound looked unremarkable. Reporting on the consensus notes diagnostic delay affecting up to 70 percent of those with the condition.
The metabolic dimension became a footnote. When a condition is filed under gynecology, the referral goes to gynecology. Blood sugar, lipids, liver, blood pressure, and cardiovascular risk were routinely left unaddressed for years, in a population where those are the outcomes that actually shorten and degrade life.
Care fragmented, and the default offer became a birth control pill. For decades the standard management was an oral contraceptive to regulate bleeding and suppress androgens, plus advice to lose weight. Neither addresses the underlying metabolic physiology.
The new name corrects all three. Polyendocrine, because multiple hormonal axes are involved. Metabolic, because insulin signaling sits at the center. Ovarian, because the ovary is where the downstream disruption becomes visible.
PMOS affects roughly 1 in 8 women worldwide, more than 170 million people. Prevalence figures of 10 to 13 percent in reproductive-aged women were confirmed through the international guideline process. The clinical picture spans far more territory than the reproductive system:
The 2023 International Evidence-based Guideline, the most rigorous document available on assessment and management, specifically strengthened recognition of metabolic risk factors, cardiovascular disease, sleep apnea, the very high prevalence of psychological features, and high-risk status during pregnancy. That guideline preceded the renaming, but it was already pointing in the same direction.
Here is the mechanism that makes the new name make sense.
When cells in muscle, liver, and adipose tissue become resistant to insulin, the pancreas compensates by producing more of it. Circulating insulin rises, often years before fasting glucose or HbA1c move at all. This state is called compensatory hyperinsulinemia, and it is invisible on a standard metabolic panel.
The ovary, critically, does not become insulin resistant. It stays fully sensitive. So while muscle and liver are being shouted at, the ovary receives that same amplified signal at full volume. Several things follow:
1. Direct stimulation of ovarian androgen production. Insulin acts on ovarian theca cells to increase androgen synthesis, in part by increasing activity of CYP17A1, a key enzyme in the testosterone pathway.
2. Amplification of luteinizing hormone. Insulin and insulin-like growth factor-1 act synergistically with LH, increasing both LH binding and the androgen response to it. Elevated LH pulse frequency is itself a hallmark of the condition.
3. Suppression of sex hormone-binding globulin. Hyperinsulinemia reduces hepatic SHBG production. SHBG is the protein that binds testosterone and keeps it inactive, so less SHBG means more free testosterone, which is the fraction that actually reaches receptors in skin and hair follicles. This is why a woman can have a total testosterone in the normal range and still have significant hirsutism and acne.
4. Follicular arrest. The androgen-rich intraovarian environment disrupts normal follicle selection. Follicles begin to develop and then stall, accumulating as the small antral follicles that gave the condition its original, misleading name.
5. A self-reinforcing loop. Androgen excess promotes visceral fat deposition. Visceral adipose tissue is metabolically active and inflammatory, which drives further insulin resistance. The cycle tightens on itself.
This is why treating the symptom at the end of the chain rarely satisfies anyone for long. Suppressing androgens with a pill while leaving hyperinsulinemia untouched is managing the smoke rather than the fire.
One of the most consequential findings in this literature, and the one most often missed in primary care, is that insulin resistance in PMOS is intrinsic, not merely a consequence of body weight.
Using the euglycemic-hyperinsulinemic clamp, the gold standard for measuring insulin sensitivity, Stepto and colleagues found insulin resistance in 75 percent of lean women with the condition, 95 percent of women with overweight, and 62 percent of BMI-matched controls with overweight who did not have it. A separate systematic review and meta-analysis of clamp studies by Cassar and colleagues found an inherent reduction in insulin sensitivity of about 27 percent, independent of BMI.
Translated: a woman with a completely normal BMI can be profoundly insulin resistant and have PMOS. She frequently is. And she is frequently told she cannot possibly have a metabolic problem because she is thin.
Compounding this, fasting insulin alone often misses insulin resistance in lean patients. Research comparing screening approaches has found that additional time points during an oral glucose tolerance test add meaningful information, because the abnormality shows up as an exaggerated postprandial insulin response before it ever affects fasting numbers. This is one of the most common reasons a patient arrives at our Tigard office having been told repeatedly that her labs are fine.
These are the outcomes the old name obscured, and the outcomes the new name is designed to put in front of every clinician who reads a chart.
Diagnosis still rests on the framework carried into the 2023 International Evidence-based Guideline, which built on the 2003 Rotterdam criteria. Two of three features are required, with other causes excluded:
Two practical points deserve emphasis. If irregular cycles and hyperandrogenism are both present, neither ultrasound nor AMH is required. The diagnosis is made. And in adolescents, both hyperandrogenism and ovulatory dysfunction are required, with ultrasound and AMH specifically not recommended because of poor specificity in that age group.
Exclusion of other causes is not optional. Thyroid dysfunction, hyperprolactinemia, non-classic congenital adrenal hyperplasia, hypothalamic amenorrhea, and Cushing's syndrome can all mimic parts of the picture.
A diagnosis alone tells you very little about what to do. The workup below is what separates a five-minute label from an actionable clinical picture.
Insulin dynamics, not just glucose. Fasting insulin and calculated HOMA-IR at minimum. Where the picture is ambiguous, particularly in lean patients, a 2-hour oral glucose tolerance test with insulin drawn at multiple time points reveals hyperinsulinemia that fasting labs miss. HbA1c and fasting glucose are included but are lagging indicators.
Androgen panel with the free fraction. Total testosterone, free testosterone, SHBG, DHEA-S, and androstenedione. Calculating the free androgen index matters because SHBG suppression is where hyperinsulinemia does much of its visible damage. Elevated DHEA-S points toward an adrenal contribution, which changes the plan.
AMH and gonadotropins. AMH, LH, and FSH. The LH-to-FSH ratio adds context even though it is not a formal diagnostic criterion.
Exclusion labs. TSH with free T4 and thyroid antibodies, prolactin, and 17-hydroxyprogesterone.
Full cardiometabolic panel. Complete lipid panel including ApoB where available, liver enzymes, hs-CRP, blood pressure, and waist circumference.
Nutrient status. 25-hydroxyvitamin D, ferritin, B12, and magnesium. Vitamin D insufficiency is common in this population, and in the Pacific Northwest it is close to universal from October through April.
Screening the rest of the picture. Sleep apnea screening, validated depression and anxiety screening, and a careful eating-behavior history. The 2023 guideline was emphatic that the psychological burden here is both severe and routinely ignored.
Environmental and exposure history. Bisphenols, phthalates, and other endocrine-disrupting compounds are plausible contributors to metabolic and reproductive dysfunction, and exposure assessment is a standard part of intake at an environmental medicine clinic.
Two patients can meet identical diagnostic criteria and need substantially different treatment. The patterns seen most often in practice:
The consistent finding across the diet literature is that improving insulin sensitivity matters more than any specific branded approach. A meta-analysis of eight randomized controlled trials in 327 patients found that lower-carbohydrate dietary patterns significantly reduced BMI, HOMA-IR, total cholesterol, and LDL cholesterol.
Clinically that looks like adequate protein at every meal, meaningful fiber intake, whole-food carbohydrate sources over refined ones, attention to meal sequencing and glycemic load, and enough dietary fat for satiety and hormone synthesis. Extreme restriction is counterproductive and, given the elevated prevalence of disordered eating in this population, sometimes actively harmful. A plan a patient can hold for a decade beats a plan she abandons in eight weeks.
Exercise is not primarily a weight-loss tool here. Skeletal muscle accounts for 70 to 80 percent of insulin-stimulated glucose uptake, which makes it the single most modifiable tissue in the entire pathophysiology.
A 2026 systematic review with pairwise and network meta-analyses found that aerobic training significantly reduced HOMA-IR and C-reactive protein, high-intensity interval training reduced fasting insulin, HOMA-IR, and LDL, combined training improved triglycerides and LDL, and yoga or Tai Chi reduced fasting glucose. An earlier meta-analysis of seven trials found HIIT effective for reducing HOMA-IR and BMI, though the authors noted the trials were small and short.
The practical translation: resistance training two to three times weekly to build the glucose-disposal tissue, plus aerobic or interval work for insulin sensitivity and inflammation. Consistency outperforms intensity.
Sleep restriction measurably worsens insulin sensitivity, and sleep apnea is substantially more prevalent in PMOS than in the general female population and frequently undiagnosed. Cortisol dysregulation compounds insulin resistance directly. Any plan that ignores sleep and stress physiology is working against itself.
Patients deserve accurate information about evidence quality, not enthusiasm. The evidence in this category is genuinely mixed, and we would rather say so.
Inositol. The most-used supplement in this space. The systematic review and meta-analysis commissioned to inform the 2023 international guidelines examined 30 trials in 2,230 participants and found evidence suggesting benefit for some metabolic measures from myo-inositol or D-chiro-inositol, and potential benefit from D-chiro-inositol for ovulation, but rated overall certainty as low and recommended shared decision-making. A separate clinical trial comparing seven different ratios found 40:1 myo-inositol to D-chiro-inositol most effective for restoring ovulation, though that trial enrolled only 56 patients across seven arms, which is a real limitation. Reasonable to trial, generally well tolerated, and worth an honest conversation about uncertainty rather than a guarantee.
Berberine. A systematic review and meta-analysis of 12 randomized trials found no solid evidence that berberine improves live birth rates. It did appear more effective than metformin for improving insulin resistance and dyslipidemia and reducing androgen levels and the LH-to-FSH ratio. Not appropriate in pregnancy or when trying to conceive, and it carries meaningful drug-interaction potential through CYP450, so it belongs under prescriber oversight rather than self-selection off a shelf.
N-acetylcysteine. Frequently promoted, but the metabolic evidence is weaker than its reputation suggests. A 2023 systematic review and meta-analysis of 11 randomized trials in 869 women found that most metabolic outcomes did not reach statistical significance, including BMI, fasting insulin, and the glucose-to-insulin ratio. An earlier meta-analysis of eight trials in 910 women did find higher odds of live birth, pregnancy, and ovulation versus placebo, while favoring metformin over NAC on pregnancy and ovulation, and its authors flagged high risk of bias in several included studies. We would not build a plan around it.
Vitamin D. A systematic review and meta-analysis of 11 randomized trials in 601 women found that vitamin D, particularly as a co-supplement or at continuous daily doses below 4,000 IU, improved fasting glucose and HOMA-IR. Notably, other meta-analyses in this area have found no effect on insulin metabolism, so the picture is not uniform. Given Oregon's latitude, testing and repletion is standard practice regardless.
Omega-3 fatty acids. Supported mechanistically and clinically for inflammation, triglycerides, and endothelial function, with a plausible role in the inflammatory phenotype specifically.
Chromium, magnesium, and coenzyme Q10 have smaller supporting literatures and can have a place in an individualized plan. None of these substitutes for nutrition, movement, and sleep.
Metformin remains a reasonable and well-studied insulin-sensitizing option. Gastrointestinal tolerance limits adherence for many patients, and long-term use warrants B12 monitoring.
GLP-1 receptor agonists are the newest entrant, and the honest summary is more measured than the marketing. A 2026 systematic review and meta-analysis of 11 randomized controlled trials found GLP-1 receptor agonists associated with a modest BMI reduction as an add-on therapy, a mean difference of 1.38 kg/m² (95% CI 0.38 to 2.39), rated low certainty. The same review concluded that evidence for metabolic, reproductive, and psychological benefit remains uncertain due to low-quality data, and that no studies evaluated cost-effectiveness. Mechanistically the rationale is strong and clinical experience in well-selected patients is often excellent, but the trial base in this specific population is still thin. We have written separately about what medically supervised GLP-1 therapy should include, and the same principles apply: lean mass protection, nutrient monitoring, gastrointestinal management, and a maintenance plan designed at the start. These medications are contraindicated in pregnancy and require a washout before conception, which is a central consideration for many patients with PMOS.
Combined oral contraceptives effectively manage cycle regularity, endometrial protection, and androgenic skin symptoms, and remain a legitimate choice. They do not treat insulin resistance, and for some patients they modestly worsen it. They are a tool, not a treatment plan.
Anti-androgens such as spironolactone address hirsutism and acne, with a required conversation about contraception given teratogenicity.
Letrozole is first-line for ovulation induction when fertility is the goal.
Insulin is actually measured. Not just glucose, not just HbA1c. The abnormality driving the syndrome is looked for directly, including in patients whose BMI suggests it should not be there.
The phenotype drives the plan. Adrenal-predominant, inflammatory, lean, and classic metabolic presentations get different interventions, not the same handout.
The metabolic terrain is the target. Nutrition, muscle, sleep, stress, inflammation, and environmental exposure are treated as the intervention rather than as background advice appended to a prescription.
Long-term risk is tracked over time. Lipids, liver, blood pressure, glycemic status, and body composition are followed longitudinally, because the outcomes that matter most unfold across decades.
The psychological burden is taken seriously. Rates of anxiety, depression, and disordered eating are high enough that the international guideline made them a headline finding. A patient who has spent a decade being told to lose weight by clinicians who never measured her insulin is carrying something real, and naming the actual mechanism is often the first genuinely therapeutic moment in her care.
Care is coordinated, not siloed. Fertility goals, thyroid function, gut health, environmental exposures, and mental health are handled in the same clinical conversation.
Dr. Maria Reebs practices at Portland Clinic of Natural Health with a clinical focus on metabolic medicine, women's health, and hormone balance, working with patients from Portland, Tigard, Beaverton, Lake Oswego, and communities across Oregon.
Her approach to PMOS reflects what the new name is trying to communicate: this is a metabolic condition with reproductive consequences, and it should be worked up and treated accordingly.
Patients working with Dr. Maria for PMOS receive:
Her work sits alongside the broader naturopathic and environmental medicine care available at Portland Clinic of Natural Health, so patients whose PMOS coexists with autoimmunity, thyroid disease, mast cell activation, gut dysfunction, or environmental illness are evaluated as a whole person rather than routed into a single-issue protocol.
Portland Clinic of Natural Health is currently accepting new patients. To be evaluated for PMOS, PCOS, or insulin resistance, apply to become a patient.
Is PMOS the same thing as PCOS?
Yes. Polyendocrine metabolic ovarian syndrome is the new official name for the condition previously called polycystic ovary syndrome. The renaming was published in The Lancet in May 2026 following a global consensus process involving 56 organizations. Your existing diagnosis remains valid, and no action is required on your part because of the name change.
Why was PCOS renamed?
Because the old name was inaccurate and was causing harm. The structures on the ovaries are not cysts, and the condition is not primarily gynecological. It is a multisystem endocrine and metabolic disorder. The old name contributed to underdiagnosis in patients without visible ovarian findings, to neglect of the metabolic and cardiovascular dimensions, and to stigma centered on fertility.
Do I have to have cysts to have PMOS?
No, and you never did. Under the current diagnostic framework you need two of three features: hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology on ultrasound or elevated AMH. If you have irregular cycles and hyperandrogenism, imaging is not required at all.
Can you have PMOS at a normal weight?
Yes. Clamp studies found insulin resistance in 75 percent of lean women with the condition. Lean PMOS is frequently missed because fasting insulin can look normal while the postprandial insulin response is markedly abnormal, which is why oral glucose tolerance testing with insulin at multiple time points is often the test that finally reveals the picture.
Is insulin resistance always the cause?
It is the predominant driver in most patients, but not the only one. Adrenal androgen excess, chronic inflammation, and post-contraceptive presentations all exist. This is exactly why phenotyping matters and why a full workup is worth doing before committing to a plan.
What labs should I ask for?
At minimum: fasting insulin with HOMA-IR, fasting glucose and HbA1c, total and free testosterone, SHBG, DHEA-S, AMH, LH and FSH, TSH, prolactin, 17-hydroxyprogesterone, a full lipid panel, liver enzymes, hs-CRP, and 25-hydroxyvitamin D. Where the picture is unclear, particularly in lean patients, a 2-hour OGTT with insulin at multiple time points adds substantial information.
Does inositol actually work for PMOS?
The evidence is promising but not definitive. The meta-analysis conducted to inform the 2023 international guidelines found suggestive benefit for some metabolic measures and possible ovulatory benefit from D-chiro-inositol, while rating overall certainty as low and recommending shared decision-making. Separate trial work supports the 40:1 ratio specifically, though that trial was small. It is generally well tolerated and reasonable to trial as part of a broader plan.
Should I take a GLP-1 medication for PMOS?
For some patients with PMOS and significant metabolic dysfunction, GLP-1 therapy is a reasonable component of care. The published trial evidence in this specific population is currently limited: a 2026 meta-analysis found a modest BMI reduction with low certainty and uncertain evidence for metabolic and reproductive outcomes. These medications are contraindicated in pregnancy and when attempting conception, which is a significant consideration for many patients. Candidacy should be assessed individually by a prescribing clinician who has evaluated your full history.
Can PMOS be reversed?
PMOS is best understood as a chronic condition that can be managed very well. Many patients achieve regular ovulatory cycles, normalized androgens, resolution of skin and hair symptoms, and substantially improved metabolic markers. The physiology tends to reassert itself when the supporting habits fall away, which is why sustainable plans outperform aggressive short-term ones.
Will treating insulin resistance help me get pregnant?
Often, yes. Improving insulin sensitivity can restore ovulation, which is the primary barrier to conception in this condition. Fertility care should be coordinated deliberately, since some agents used for metabolic management are inappropriate during conception attempts and pregnancy.
All citations below were verified against PubMed or the publisher of record.
This article is intended for general educational purposes and does not constitute medical advice, diagnosis, or treatment. Polyendocrine metabolic ovarian syndrome (PMOS), previously known as polycystic ovary syndrome (PCOS), is a complex condition requiring individualized evaluation by a qualified healthcare provider. Laboratory interpretation, supplement selection, and medication decisions should be made in the context of your complete medical history. Several agents discussed here, including berberine and GLP-1 receptor agonists, are not appropriate during pregnancy or when attempting to conceive. Do not start, stop, or change any medication or supplement without consulting a qualified healthcare provider who has evaluated you individually. If you are pregnant, breastfeeding, taking medication, or managing another medical condition, discuss these factors with your provider before making changes to your care.
