Types of PCOS: Phenotypes A–D, Lean & Adrenal (Canada)
There are four clinically recognized types of PCOS, phenotypes A through D, defined by which combination of the Rotterdam criteria a person meets, plus a distinct lean presentation that doesn't follow the usual weight-loss rule. Rotterdam requires two of three features: androgen excess, irregular ovulation, and polycystic ovarian morphology on ultrasound. Phenotype A has all three (the "classic" presentation); B has androgen excess and irregular ovulation without meeting the ovarian-morphology criterion; C has androgen excess and polycystic ovaries with regular cycles; D has irregular ovulation and polycystic ovaries without androgen excess. The two hyperandrogenic phenotypes, A and B, carry the highest reported metabolic-risk burden (more insulin resistance, more cardiovascular risk factors) while D tends to run mildest. Roughly one in five women with PCOS present at a normal body weight ("lean PCOS"), where the standard 5–10% weight-loss target does not apply. You may also have read about "adrenal PCOS" online: a popular label for a real lab finding (elevated DHEA-S) that isn't part of the formal A–D classification. For the full diagnostic picture, see what PCOS is; for how phenotype should shape your treatment plan, see PCOS treatment in Canada.
Naming note: In May 2026, PCOS was formally renamed polyendocrine metabolic ovarian syndrome (PMOS) by global consensus published in The Lancet. The phenotype classification below applies identically under both names. See our PCOS-to-PMOS explainer for the rename context, including why the new name leans into the same metabolic emphasis that phenotypes A and B already point to. This article uses "PCOS" because that remains the term most patients are searching for during the transition period.
The 4 types of PCOS: Rotterdam phenotypes A through D
Every clinically recognized type of PCOS comes from the same three-criteria framework; which two (or three) of them a person meets determines the phenotype, labelled A through D. The Rotterdam criteria require at least two of: clinical or biochemical androgen excess, irregular or absent ovulation, and polycystic ovarian morphology on ultrasound (or an elevated anti-Müllerian hormone level, where ultrasound isn't feasible). A diagnosis of PCOS is a diagnosis of one of these four combinations:
- Phenotype A (classic PCOS): androgen excess, irregular ovulation, and polycystic ovarian morphology, all three. The most-studied phenotype and, in most clinic-based samples, the most common, often accounting for around half of diagnosed patients.
- Phenotype B (non-PCOM): androgen excess and irregular ovulation, without meeting the ovarian-morphology criterion. Shares the hyperandrogenism-plus-anovulation combination with phenotype A.
- Phenotype C (ovulatory PCOS): androgen excess and polycystic ovarian morphology, with regular menstrual cycles. Ovulation is intact, which is why this group is sometimes missed at first pass if a clinician is anchoring heavily on cycle irregularity.
- Phenotype D (non-hyperandrogenic PCOS): irregular ovulation and polycystic ovarian morphology, without clinical or biochemical androgen excess. The only phenotype that doesn't involve elevated androgens at all.
A 2024 cardiometabolic review in Medicina puts phenotype A at roughly 50–60% of diagnosed cases in clinic-based cohorts, B at 20–30%, C at 10–15%, and D at 5–10%, though population-screening studies (as opposed to samples drawn from specialty clinics) tend to find relatively more of phenotype D, since it produces the mildest symptoms and is least likely to prompt a referral in the first place. The same review is explicit that cardiovascular risk is "especially" elevated in phenotypes A and B, where hyperandrogenism, abdominal obesity, and insulin resistance are more pronounced. The gradient isn't perfectly linear in every individual study; smaller cohorts occasionally show B and A trading places on a given metabolic marker. But the pattern holds across the broader literature: androgen excess is the variable most consistently tied to higher metabolic risk, and the phenotype that lacks it, D, runs milder on average. Phenotype C tends to sit in between.
None of this changes how PCOS is diagnosed or treated at the foundation. It changes emphasis: how closely your metabolic markers get watched, and which symptoms your care plan weights most heavily. More on that below.
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Lean PCOS: PCOS at a normal weight
Lean PCOS is the guideline-recognized presentation of PCOS at a normal body-mass index, and it's common enough that any complete list of PCOS "types" has to include it even though it isn't one of the four letter phenotypes. Roughly one in five women with PCOS present at a normal or low BMI rather than the overweight or obese range most PCOS research and marketing assumes by default.
The detail that matters most for lean PCOS: the 5–10% sustained weight-loss target that anchors most PCOS treatment guidance does not apply here. That target is the high-evidence recommendation specifically for women who carry excess weight. The 2023 international guideline frames it that way explicitly, and a clinical review on lean PCOS puts it plainly: weight loss is considered first-line treatment for the overweight PCOS phenotype, but it is not part of the standard approach for lean patients. Pursuing a calorie deficit anyway, when there's no excess weight to lose, isn't indicated and can work against you.
That doesn't mean lean PCOS is a milder version of the condition. Insulin resistance is still common in lean PCOS. Research consistently finds elevated fasting insulin and reduced insulin sensitivity in lean patients compared with women of similar weight who don't have PCOS, even though the mechanism is harder to see without the visible weight change that usually prompts a workup. Androgen excess, cycle irregularity, and the associated symptoms (hirsutism, acne, scalp thinning) show up in lean PCOS at rates broadly similar to the overweight presentation.
Because the scale-based target is off the table, lean PCOS management focuses on three things instead:
- Insulin sensitivity through diet composition and movement, rather than a calorie deficit: resistance training, lower glycemic-load eating, and protein adequacy, aimed at the underlying metabolic mechanism rather than the number on the scale.
- Androgen-symptom management: the same hirsutism, acne, and scalp-thinning treatment options used in any PCOS phenotype, since androgen excess doesn't track with body weight.
- Cycle regularity, tracked and managed the same way regardless of BMI.
If you're lean and have been told your PCOS "isn't that bad" because your weight is normal, that's a common but inaccurate read. Insulin resistance and androgen excess are the drivers either way; body weight is one variable among several, not the diagnosis itself.
The popular "adrenal PCOS" label — what the DHEA-S finding actually means
"Adrenal PCOS" is a popular label for a real lab finding: elevated DHEA-S, an androgen produced almost exclusively by the adrenal glands. It isn't one of the four clinically recognized phenotypes, and it's worth being straightforward about that distinction.
DHEA-S shows up on a standard androgen panel alongside testosterone. Because roughly 90% of circulating DHEA-S originates in the adrenal glands rather than the ovaries, an elevated result, with testosterone in a more typical range, points toward an adrenal contribution to a person's androgen excess. This is a real and fairly common finding: a retrospective analysis of PCOS patients in their twenties found DHEA-S elevated in about a third of the group overall, and notably more often in phenotypes B and C than in the full phenotype A.
What that finding does not do is create a fifth clinical category. The Rotterdam criteria and the 2023 international guideline classify PCOS by phenotype A through D, based on the three diagnostic features described above, not by which gland produced the excess androgen. An elevated DHEA-S is a data point your clinician factors into your specific picture (it can inform which symptoms to expect and occasionally prompts a check for other adrenal causes), but it sits inside your existing phenotype rather than replacing it.
If you arrived at this article searching for "adrenal PCOS" specifically, you're not off base — you're looking at a genuine physiological detail that the online PCOS community has built a name around. The next section covers how that label, and a few others like it, relate to the classification your chart actually uses.
Internet PCOS "types" vs. the clinical phenotypes
The wellness-community PCOS "types," commonly labelled insulin-resistant, inflammatory, adrenal, and post-pill, aren't recognized in the Rotterdam criteria or the 2023 international guideline, but they aren't fabricated out of nothing either. Each one is a popular framing built around a real physiological pattern that shows up in some PCOS patients:
- "Insulin-resistant PCOS" points at the insulin-resistance mechanism present in a majority of PCOS patients across every Rotterdam phenotype. It's real, just not phenotype-specific.
- "Inflammatory PCOS" points at elevated inflammatory markers seen in some PCOS research, a genuine area of study rather than a distinct diagnostic category.
- "Adrenal PCOS" points at the DHEA-S finding covered above.
- "Post-pill PCOS" points at the temporary cycle irregularity some people experience after stopping hormonal contraception, which can look like PCOS symptoms without meeting Rotterdam criteria once cycles settle.
The reason clinicians use the A–D framework instead comes down to how each system was built. The Rotterdam phenotypes are derived directly from the three diagnostic criteria, so they're reproducible from a chart and a lab panel, they correlate with measured metabolic-risk data across large cohorts, and they're what your family physician, OB-GYN, or endocrinologist will actually document. The internet taxonomy describes plausible drivers and is genuinely useful as a way to organize symptoms in your own head. But the categories aren't standardized across the sources that use them, there's no single test that assigns you to one, and leaning on a self-assigned "type" can delay the bloodwork and ultrasound that would actually confirm your Rotterdam phenotype and rule out other causes of your symptoms.
Both things can be true at once: the popular framing captured something real enough to resonate with a lot of patients, and it still isn't a substitute for the classification your clinician uses to make decisions about your care.
Why your phenotype matters for care intensity
Your phenotype should change how closely your metabolic markers get monitored, not just which symptoms your plan targets first. Because phenotypes A and B carry the higher documented cardiometabolic-risk burden, they generally warrant a tighter screening cadence: periodic HbA1c or fasting glucose, a lipid panel, and blood pressure checks, consistent with the ongoing screening the Diabetes Canada Clinical Practice Guidelines recommend for PCOS given its elevated long-term type 2 diabetes risk.
Phenotypes C and D still carry more metabolic risk than the general population (PCOS as a whole is associated with elevated long-term cardiometabolic risk regardless of phenotype), but the evidence supports a somewhat less intensive monitoring cadence for the non-hyperandrogenic presentations, with baseline screening still in place for everyone at diagnosis.
In practice, this means two people with a PCOS diagnosis can have meaningfully different care plans even though the lifestyle-first foundation looks the same on paper: one leans harder on quarterly lab review and androgen-symptom management, the other checks in less frequently and focuses more on cycle tracking. A program that treats every PCOS diagnosis identically, without factoring in phenotype, is running a less precise version of the 2023 guideline than the evidence supports. For the underlying mechanism connecting phenotype, androgens, and metabolic risk, our insulin resistance guide covers the biology in more depth.
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How Cloudcure approaches phenotype-specific PCOS care
Most Canadians leave a PCOS diagnosis with a label and little else: rarely a phenotype, and almost never a screening plan calibrated to it. Cloudcure's PCOS care program is built to close that gap, in coordination with your existing care team rather than around it.
- A baseline workup that includes total and free testosterone, DHEA-S, sex hormone-binding globulin (for a calculated free-androgen index), HbA1c, fasting insulin, and a lipid panel, enough to place you within the A–D framework and flag an adrenal-androgen contribution where it's present.
- A 12-month structured arc with monthly clinician follow-up and lab reviews at months 3, 6, and 12, with cadence adjusted to your phenotype's risk profile rather than a single fixed schedule for everyone.
- Behavioural and nutrition coaching calibrated to whether weight reduction is or isn't part of your specific picture, including lean-PCOS patients, where the plan focuses on insulin sensitivity and symptom control rather than a weight target.
- Coordination with your family physician, OB-GYN, or endocrinologist, with labs and phenotype context shared back so your existing providers have the full picture, not just a diagnosis code.
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The bottom line
PCOS isn't a single presentation. It's four Rotterdam-derived phenotypes (A through D), distinguished by which combination of androgen excess, irregular ovulation, and ovarian morphology a person has, with a metabolic-risk gradient that runs highest in the two hyperandrogenic phenotypes, A and B, and mildest in D. Layered on top of that is lean PCOS, the roughly one-in-five presentation at a normal body weight where the usual weight-loss target simply doesn't apply. The "adrenal PCOS" label you may have found online points at something real — an elevated DHEA-S result — but it's a lab detail inside the A–D classification, not a fifth category. Knowing your specific phenotype is what lets a screening plan, and a treatment plan, actually match your risk instead of defaulting to a generic PCOS protocol.
If you have a PCOS diagnosis but have never been told your phenotype, that's a reasonable question to bring to your family physician or OB-GYN at your next visit. For the full diagnostic picture, start with our guide to what PCOS is, or return to the PCOS resource hub for our complete library of Canadian PCOS content.