What changed
On 12 May 2026, a paper in The Lancet announced that polycystic ovary syndrome would be renamed polyendocrine metabolic ovarian syndrome, abbreviated PMOS. The work was led by Professor Helena Teede's team at Monash University together with the Androgen Excess and PCOS Society and the UK patient charity Verity, and it closed a 14-year consensus process involving 56 patient and professional organisations and more than 14,000 survey responses from people with the condition and the clinicians who treat them.
Each word in the new name was chosen deliberately:
- Polyendocrine. Several interacting hormone systems are involved, chiefly insulin, androgens and the brain signals that control ovulation.
- Metabolic. Insulin resistance, weight gain and a higher long-term risk of type 2 diabetes and cardiovascular disease are core features of the condition, not side effects of it.
- Ovarian. Ovulation problems and fertility remain part of the picture, so the ovary stays in the name.
What was dropped is "polycystic." The "cysts" seen on ultrasound are immature follicles, not true cysts, and you do not need them to have the condition. The researchers behind the change link the misleading name to delayed diagnosis affecting up to 70% of people who have it. Not everyone loves the replacement: a letter in The Lancet has questioned whether "polyendocrine" is the right word, since in endocrinology it usually describes failure of several glands. The name is adopted regardless.
What did not change
- The diagnostic criteria. You still need two of three features: irregular or absent ovulation, signs of excess androgens on examination or blood tests, and polycystic ovarian morphology on ultrasound (or an AMH blood test in adults). If you were diagnosed with PCOS, you have PMOS. Nothing needs re-confirming.
- Treatment. The 2023 International Evidence-based Guideline still governs care. Its next update, in 2028, is when the new name is fully written in.
- Your prescriptions. Metformin, spironolactone, combined pills, letrozole and GLP-1 medicines are prescribed for the same reasons at the same doses.
- Your records, for now. The transition is planned over roughly three years, with the new term being added to health-record coding systems and taken to the World Health Organization for disease classification. Expect both names side by side on lab reports and letters for a while, and the old name in older materials for much longer.
Why the new name still matters for your supplements
Most supplements people take for PCOS target one of three things: insulin resistance (inositol, berberine, NAC, chromium, cinnamon), androgen-driven symptoms such as hair loss, acne and facial hair (spearmint, zinc, saw palmetto), or a nutrient the condition or its medicines tends to run down (vitamin D, B12, magnesium).
The new name puts the first group, the metabolic one, at the centre of how the condition is described. That does not make those supplements more effective than they were last year. It does mean the questions PCOS patients have been asking for a decade, starting with "is inositol worth taking if I'm already on metformin," are now the mainstream questions. Expect more marketing that attaches the word "metabolic" to products. The evidence underneath has not moved.
Supplement by supplement
Inositol and metformin.
The most-searched PCOS supplement, and the one most often mentioned alongside the rename. The systematic review that informed the 2023 guideline found inositol may help some metabolic measures, and D-chiro-inositol may support ovulation, but concluded the overall evidence is limited and inconclusive. The guideline favours metformin over inositol for hirsutism and central weight, while noting that inositol causes fewer stomach side effects. If you take inositol alongside metformin, both lower blood glucose, so the pairing is worth a conversation with your prescriber, particularly if you ever feel light-headed or shaky between meals.
Metformin and vitamin B12.
The metabolic emphasis will likely put more people on metformin, and long-term metformin reduces B12 absorption. The American Diabetes Association recommends periodic B12 checks for people on metformin, and the UK medicines regulator lists low B12 as a common side effect. This was true before May and is unchanged. If you have been on metformin for a few years and have not had B12 checked, ask.
Anti-androgen supplements: spearmint, zinc, saw palmetto.
The "ovarian" in PMOS keeps androgen excess in view. If you take spironolactone, adding further anti-androgen supplements on top is the question to raise before you start them, not after. Nothing about the name changes those interactions.
Berberine, NAC, chromium, cinnamon.
Each has modest, mixed evidence, mostly from small trials, and that is unchanged. Any of them combined with metformin or a GLP-1 medicine can add to glucose-lowering. Read the berberine and metformin guide and check the pair, not the label.
What not to do: change, add or drop a supplement because of the rename. If your stack was reviewed with your clinician before May, it is still reviewed.
Three questions for your doctor or pharmacist
- Is my diagnosis recorded as PCOS or PMOS, and does it affect referrals or insurance? (It should not, but ask.)
- Given the metabolic emphasis, should I be screened for insulin resistance, lipids or blood pressure if I have not been recently?
- Here is my current supplement list. Does anything on it interact with what you have prescribed?
Check your own stack
Frequently asked questions
Is PMOS the same as PCOS?
Yes. Same condition, same diagnostic criteria, same treatments. Only the name changed, in May 2026.
Do I need a new diagnosis?
No. An existing PCOS diagnosis is a PMOS diagnosis.
Will my doctor use the new name?
Gradually. The transition is planned over about three years, and the new name is being added to health-record systems and to the 2028 guideline update. You may see both names on the same document for a while.
Should I change my supplements because of PMOS?
No. The evidence base is unchanged. Any change should come from a conversation with your prescriber about your actual medications, not from the new name.
Sources
- Teede HJ, Khomami MB, Morman R, et al. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. Lancet. 2026;407(10545):2329-2339. https://doi.org/10.1016/S0140-6736(26)00717-8
- Piltonen T, Kuusiniemi E, Teede HJ. Ovarian cysts in polycystic ovary syndrome. JAMA Intern Med. 2026. https://doi.org/10.1001/jamainternmed.2026.1370
- From PCOS to PMOS: perspectives on the new nomenclature (correspondence). Lancet. 2026. https://doi.org/10.1016/S0140-6736(26)01081-0
- Teede HJ, et al. Recommendations from the 2023 International Evidence-based Guideline for the Assessment and Management of PCOS. J Clin Endocrinol Metab. 2023;108(10):2447-2469. https://academic.oup.com/jcem/article/108/10/2447/7242360
- Inositol for polycystic ovary syndrome: systematic review and meta-analysis to inform the 2023 guideline update. J Clin Endocrinol Metab. 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11099481/
- American Diabetes Association. Standards of Care in Diabetes, pharmacologic approaches (metformin and vitamin B12 monitoring). https://diabetesjournals.org/care
- Monash Centre for Health Research and Implementation. How the new name was chosen (patient resource). https://www.mchri.org.au/
- Contemporary OB/GYN. Global consensus renames PCOS to PMOS (summary of the eight implementation stages). 12 May 2026. https://www.contemporaryobgyn.net/view/global-consensus-renames-pcos-to-polyendocrine-metabolic-ovarian-syndrome-pmos-
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Always consult your physician before starting any supplement, especially if pregnant, nursing, or taking medication.