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PCOS (Now PMOS) and Irregular Cycles: Diagnosis, Treatment and Supplements, by the Evidence

PCOS was renamed polyendocrine metabolic ovarian syndrome (PMOS) in 2026, but how it is diagnosed has not changed. The 2023 international guideline backs the pill for irregular cycles and excess hair, metformin for metabolic risk, and calls the evidence for inositol limited.

By Kymata Health editorial teamLast verified October 10, 2026

Medical review pending. Written by our editorial team from the studies and documents cited below; a credentialed clinician has not reviewed it yet. Educational only, not medical advice.

Key takeaways

  • In 2026 polycystic ovary syndrome was renamed polyendocrine metabolic ovarian syndrome (PMOS) after a global consensus process involving 56 organisations; the diagnostic criteria stayed the same [2][3].
  • Diagnosis needs 2 of 3 features: irregular cycles or ovulatory dysfunction, high androgens (lab tests or signs such as excess hair), and polycystic ovaries on ultrasound or, in adults only, a high AMH blood level [1].
  • The 2023 guideline says the combined pill could be used over metformin for excess hair and irregular cycles, and metformin over the pill for metabolic goals [1].
  • A 2024 meta-analysis of 30 inositol trials (2,230 women) called the evidence limited and inconclusive [4].
  • For women with PCOS who do not ovulate and want to conceive, the guideline makes letrozole the first-line medicine to induce ovulation [1].

Guides in this hub

  1. How PCOS (PMOS) Is Diagnosed: Cycle Length, Androgens and the AMH TestPCOS, now called PMOS, is diagnosed with 2 of 3 features: irregular cycles, high androgens and polycystic ovaries. Since 2023 an AMH blood test can stand in for the ultrasound in adults, but not in teenagers and never on its own.
  2. Birth Control Pill vs Metformin for PCOS: What the 2023 Guideline RecommendsThe international PCOS guideline favours the combined pill for excess hair and irregular cycles and metformin for metabolic goals, with little gain from taking both unless metabolic risk is high. For fertility, letrozole comes first.
  3. Inositol for PCOS: What the Trials Show for Cycles, Weight and FertilityInositol may improve some metabolic measures in PCOS, but a review of 30 trials found little effect on other outcomes and called the evidence limited and inconclusive. The international guideline treats it as an option, not a fertility treatment.

PCOS has a new name

The condition affects about one in eight women [2]. The old name implied pathological ovarian cysts; the follicles seen on ultrasound are arrested antral follicles, not cysts, and the new name, polyendocrine metabolic ovarian syndrome, reflects its hormonal and metabolic features [2][3].

The name was chosen through a consensus process that drew survey responses from 14,360 people with the condition and health professionals [2]. Diagnostic criteria are unchanged [3], so a past PCOS diagnosis still stands. You will see both names during the transition.

How it is diagnosed

After the teenage years, cycles shorter than 21 days, longer than 35 days, or fewer than 8 a year count as irregular [1]. If you have irregular cycles and signs of high androgens, an ultrasound or AMH test is not needed for diagnosis [1].

Ovulation problems can occur even with regular cycles, and a blood progesterone test can confirm whether you ovulated [1]. Our diagnosis guide covers the criteria, the AMH test and testing while on the pill.

Treatment options

The guideline gives the combined oral contraceptive pill and metformin different jobs: the pill for excess hair and irregular cycles, metformin for metabolic outcomes such as insulin resistance, glucose and cholesterol, especially with a BMI of 25 or more [1]. Weight-loss medicines including GLP-1 drugs could be considered alongside lifestyle changes for higher weight, as in the general population [1].

The guideline also recommends screening everyone with PCOS for depression and anxiety [1]. Our pill vs metformin guide compares the options, including fertility treatment.

Inositol and other supplements

Inositol could be considered based on personal preference, but the guideline notes limited clinical benefits for ovulation, excess hair or weight, and says metformin should be considered over inositol for excess hair and central weight [1].

For fertility, inositol should be considered experimental [1]. Our inositol guide covers the trials.

Tracking your cycle

A record of cycle lengths helps your clinician apply the irregular-cycle definition [1]. Natural Cycles, an app the FDA authorized in 2018 for contraception or pregnancy planning, says it can be used with PMOS and can flag irregular cycles, but that users may see more Red Days [5][6].

Partners we link to

Paid links: we earn a commission if you buy through these, at no extra cost to you. It never changes what the evidence sections say. Affiliate disclosure.

  • Natural CyclesPaid linkAn app the FDA authorized in 2018 for contraception or planning a pregnancy in women 18 and older; it reads your temperature data to flag fertile days. Natural Cycles says it can be used with PMOS (PCOS), but you may get more Red Days, and it does not protect against STIs.See Natural Cycles

Regulatory and legal notes

  • Inositol is sold as a dietary supplement. The FDA does not approve supplements before they are marketed, and a supplement may not legally claim to treat a disease such as PCOS [7]. The guideline adds that inositol's regulatory status and quality control differ from medicines and that doses and quality may vary [1].
  • Letrozole's use to induce ovulation is off-label in many countries, according to the 2023 guideline [1].
  • Pregnancy safety data are lacking for GLP-1 drugs, so the guideline advises effective contraception when pregnancy is possible [1].
  • Natural Cycles was classified by the FDA in August 2018 as a software application for contraception, for women 18 and older; its required labeling includes warnings that no contraceptive is 100% effective and that the app does not protect against sexually transmitted infections [6].

Other names you will see

Listed for completeness. We have no paid relationship with these brands and do not link to them.

  • Elix: Sells personalized liquid Chinese herbal formulas (Cycle Balance, $48 a bottle on its site, October 2026). Its PCOS/PMOS results come from its own open-label study of 70 participants with no placebo group and self-reported outcomes; Elix says it plans a placebo-controlled trial.

References

  1. [1]Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. J Clin Endocrinol Metab, 2023. PMID 37580314
  2. [2]Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. Lancet, 2026. PMID 42119588
  3. [3]From polycystic ovary syndrome to polyendocrine metabolic ovarian syndrome: what obstetricians and gynecologists need to know. Am J Obstet Gynecol, 2026. PMID 42665241
  4. [4]Inositol for Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis to Inform the 2023 Update of the International Evidence-based PCOS Guidelines. J Clin Endocrinol Metab, 2024. PMID 38163998
  5. [5]Can I use Natural Cycles if I have PMOS (formerly PCOS)?. Natural Cycles, 2026.
  6. [6]De Novo classification order DEN170052: Natural Cycles (software application for contraception). U.S. Food and Drug Administration, 2018.
  7. [7]Questions and Answers on Dietary Supplements. U.S. Food and Drug Administration, 2026.

Dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Prescription options need a licensed clinician. Talk to your clinician or pharmacist before starting anything new, especially if you take prescription medicines, are pregnant or breastfeeding.

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