Evidence explainerPCOS & Cycle

How PCOS (PMOS) Is Diagnosed: Cycle Length, Androgens and the AMH Test

PCOS, 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.

By Kymata Health editorial teamPublished October 10, 2026Last 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

  • Diagnosis requires 2 of 3: irregular cycles or ovulatory dysfunction, clinical or biochemical high androgens, and polycystic ovarian morphology on ultrasound or a high AMH level, after other causes are excluded [1].
  • In adults, AMH identified PCOS with 79% sensitivity and 87% specificity in pooled studies; in adolescents it was 66% and 78% [2].
  • The guideline says AMH should not be used as a single test or in adolescents, and no international cut-off has been set [1][2].
  • The 2026 renaming to polyendocrine metabolic ovarian syndrome did not change the diagnostic criteria [4].

The criteria

The 2023 guideline builds on the 2003 Rotterdam criteria: two of clinical or biochemical hyperandrogenism, ovulatory dysfunction, and polycystic ovaries on ultrasound, or a high AMH level instead of ultrasound, with other causes excluded [1].

Where irregular cycles and hyperandrogenism are both present, ultrasound or AMH is not needed. In adolescents, both hyperandrogenism and ovulatory dysfunction are required, and ultrasound and AMH are not recommended [1].

What counts as an irregular cycle

From 3 years after the first period until perimenopause, the guideline defines irregular cycles as shorter than 21 days, longer than 35 days, or fewer than 8 cycles a year; any single cycle over 90 days counts from 1 year after the first period [1].

Ovulatory dysfunction can occur even with regular cycles, and a blood progesterone test can confirm ovulation if needed [1]. Natural Cycles says its app can show how irregular your cycles are and when, or if, you ovulate, which you can share with your clinician [5].

Testing androgens

The guideline recommends total and free testosterone to assess biochemical hyperandrogenism [1]. Testing is hard while taking the combined pill, which raises sex hormone-binding globulin; if testing is essential, the guideline advises stopping the pill for at least 3 months and using other contraception [1].

The AMH test

A 2024 meta-analysis that informed the guideline pooled 68 adult studies: AMH had a sensitivity of 0.79 and specificity of 0.87 for PCOS. In 11 adolescent studies the figures were 0.66 and 0.78, and many factors affect AMH levels, so no international cut-off could be set [2].

The guideline says AMH could be used to define polycystic ovarian morphology in adults, only within the diagnostic algorithm, never as a single test, and not yet in adolescents [1].

The new name

A 2026 global consensus renamed the condition polyendocrine metabolic ovarian syndrome (PMOS), dropping the reference to cysts [3]. The criteria remain 2 of 3: irregular cycles and ovulatory dysfunction, hyperandrogenism, and high AMH or many follicles on ultrasound in adults [4].

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

Quick answers

Do I need cysts on an ultrasound to have PCOS?

No. The ovarian appearance reflects many arrested follicles, not cysts [4], and if you have irregular cycles plus high androgens, no ultrasound or AMH test is needed for diagnosis [1].

Can I be tested for PCOS while on the pill?

Androgen tests are hard to interpret on the combined pill; the guideline advises stopping it for at least 3 months, with other contraception, if testing is essential [1].

More in PCOS & Cycle

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]Anti-müllerian hormone as a diagnostic biomarker for polycystic ovary syndrome and polycystic ovarian morphology: a systematic review and meta-analysis. Fertil Steril, 2024. PMID 38944177
  3. [3]Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. Lancet, 2026. PMID 42119588
  4. [4]From polycystic ovary syndrome to polyendocrine metabolic ovarian syndrome: what obstetricians and gynecologists need to know. Am J Obstet Gynecol, 2026. PMID 42665241
  5. [5]Can I use Natural Cycles if I have PMOS (formerly PCOS)?. Natural Cycles, 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.

Keep reading: Supplements and vitamins

Supplements and vitamins: every page →Supplement & Nutrient Encyclopedia →Browse all topics →

Previous in this topicPCOS (Now PMOS) and Irregular Cycles: Diagnosis, Treatment and Supplements, by the EvidencePCOS was renamed polyendocrine metabolic ovarian syndrome (PMOS) in 2026, but how it is diagnosed has not changed.Next in this topicBirth 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…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.Methylene Blue & NAD+ Peptides: The Mitochondrial Enhancement StackMethylene blue acts as an alternative electron carrier in the mitochondrial chain.NMN vs NR vs NAD+: Precursors, Coenzyme, and What Head-to-Head Human Data ShowNMN vs NR vs NAD+ comparison using opened human precursor trials.

Evidence-graded supplement stacks →