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PMOS (formerly PCOS): the four subtypes, and why it matters
7 sections · 5 min read
Why is PMOS (formerly PCOS) not a single condition?
The four PMOS subtypes, at a glance
Insulin-resistant
The most common subtype. Cells respond less to insulin → pancreas makes more → ovaries make extra androgens. Often shows weight gain around the abdomen, sugar cravings, acanthosis nigricans, skin tags. Responds to blood-sugar-stable eating, resistance training, myo-inositol (2–4 g), metformin in clinic.
Adrenal, often lean phenotype
Excess androgens come from the adrenal glands rather than the ovaries. DHEA-S elevated, testosterone often normal. Seen in roughly 1 in 4 women with PMOS at a normal weight. Stress and sleep matter more than weight here.
Post-pill
A temporary PMOS-like picture that can appear after stopping the combined pill. For many, cycles regulate within 12 months. If symptoms persist beyond a year, formal investigation is reasonable, the pill may have masked an underlying picture.
Inflammatory
Chronic low-grade inflammation drives the hormonal picture. Often shows alongside joint pain, frequent headaches, gut symptoms, coeliac disease, or thyroid conditions. Anti-inflammatory eating, gut-health support, and treating the underlying inflammatory source matter more than standard PMOS management alone.
How is PMOS diagnosed using the Rotterdam criteria?
Quick check
Have you ever been told you can't have PMOS because your weight is in the normal range?
What is insulin-resistant PMOS and why is it the most common subtype?
The body produces excess insulin, which signals the ovaries to produce additional male hormones. Characteristics include weight gain particularly around the abdomen, sugar cravings, darkened skin patches (acanthosis nigricans) on neck or underarms, and skin tags.
This subtype responds well to dietary modifications supporting blood-sugar stability, regular moderate exercise (particularly resistance training), myo- supplementation (2–4 g daily, Cochrane-reviewed evidence), and metformin in clinical practice.
What is post-pill PMOS and how long does it last?
Some women find menstrual cycles do not return properly after stopping hormonal contraception, or develop symptoms not present before. It remains unclear whether this represents true PMOS or temporary hormonal disruption.
For many women, cycles regulate within one year. Persistent symptoms beyond this timeframe warrant formal investigation, the contraceptive pill may have masked an underlying condition for years.
What is adrenal PMOS and why is it often missed in lean women?
In this subtype, excess hormones originate from the adrenal glands rather than the ovaries. Blood tests show elevated DHEA-S, but may be normal or only slightly raised. This subtype is seen in approximately 1 in 4 women with PMOS who are at a normal weight.
The assertion that PMOS cannot be present in women who are not overweight is clinically incorrect. Lean women experience the same symptoms, irregular periods, excess hair, acne, difficulty conceiving, but stress and sleep management are often more impactful than weight-focused interventions for this subtype.
What is inflammatory PMOS and how is it different?
Ongoing low-level systemic inflammation disrupts hormones and cycles. Often accompanied by other inflammatory conditions such as joint pain, frequent headaches, or digestive issues (coeliac disease, thyroid conditions).
This subtype improves with anti-inflammatory dietary approaches, gut-health support, and treatment of the underlying inflammatory source, not with the typical PMOS management alone.
What should you ask your doctor when exploring PMOS subtypes?
Myth
PMOS only affects overweight women. If your BMI is normal, you can't have it.
Evidence
Around 30–40% of women with PMOS are at a normal BMI. Adrenal-driven and inflammatory subtypes commonly present at normal weight. South Asian bodies particularly often have insulin-resistant PMOS at BMI under the standard 25 cut-off.
Teede HJ et al. 2023 International PCOS Guidelines
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Reviewed by clinicians
Authored and reviewed by clinicians from the founding team. Information only, not personalised medical advice.