The PCOS (PMOS) Lab Panel Most People Get vs. The One That Actually Explains What’s Going On

 

Clinically written and reviewed by Dr. Alessia Milano, ND, a licensed naturopathic doctor registered with the College of Naturopaths of Ontario (Reg. #3697). Last reviewed October 2026.

“I was diagnosed with PCOS from an ultrasound.”

I hear this ALL the time in my practice. Sometimes there’s blood work alongside it, but it’s usually very basic: a CBC, maybe a few nutrients, maybe one or two androgens. A full hormonal workup that rules out the conditions that mimic PCOS (PMOS) is rare. An assessment of what’s actually driving someone’s symptoms is even rarer.

The reality is that an ultrasound alone can’t diagnose PCOS (PMOS), and a basic panel can’t tell you what’s making it worse. Without both of those pieces, it’s very hard to choose a treatment that actually works for your PCOS.

Today I’m going to take you through what most people get tested for, what a comprehensive PCOS (PMOS) workup actually looks like, and one test that’s far less useful than most people think. That way, you can look at your own labs and know exactly what’s been covered and what hasn’t.

The Panel Most People Get

When patients come to me with blood work, it usually looks something like this:

  • A CBC

  • A few nutrients, like iron or vitamin B12

  • Maybe total testosterone, and rarely the full set of androgens

It doesn’t confirm PCOS (PMOS), namely because it doesn’t rule out the conditions that look identical to it, and it tells us almost nothing about the factors driving it forward.

The Panel That Actually Explains What’s Going On

When I work up PCOS (PMOS) in our clinic, I’m trying to answer three questions:

  1. Is this actually PCOS?

  2. Have we ruled out everything that mimics it?

  3. What’s driving it for this particular person?

Here’s what that looks like.

Step 1: Confirming the Diagnosis

PCOS (PMOS) is diagnosed using the Rotterdam Criteria, which were updated in the 2023 international PCOS guideline. To be diagnosed, you need to meet two of these three criteria:

1. Irregular or absent periods. For adults, this generally means cycles shorter than 21 days or longer than 35 days, or fewer than 8 periods a year. The definition is a bit different for teens in the first few years after their first period, because irregular cycles are normal while things are still settling.

2. Hyperandrogenism, meaning high androgens. This can show up in two ways:

  • Clinical signs, which are what we can see: excess hair growth on the face or body, acne, or hair thinning on the scalp.

  • Biochemical signs, which are what shows up on blood work. The guideline recommends testing total testosterone and sex hormone binding globulin (SHBG), which together tell us how much testosterone is free and active. I also test DHEAS, which can point toward adrenal involvement, and in some cases androstenedione.

3. Polycystic ovarian morphology on ultrasound, OR an elevated AMH. Here’s where things have really changed! A polycystic appearance on ultrasound is common in people who don’t have PCOS at all, which makes it the least reliable of the three criteria. The 2023 guideline now allows AMH (anti-Müllerian hormone) to be used in place of an ultrasound for adults. If you already meet the first two criteria, you don’t need an ultrasound or AMH at all. Neither is used for diagnosis in teens.

Meeting two of three is only half of it, though. PCOS (PMOS) is a diagnosis of exclusion, which means every other condition that could explain your symptoms has to be ruled out first. That brings us to Step 2.

Step 2: Ruling Out the Look-Alikes

This is the step I see skipped most often, and it’s SO important. Here are the conditions we want to rule out, and the testing for each:

  • Hypothyroidism. Tested with TSH, plus a fuller thyroid panel if needed. 

  • Hyperprolactinemia, or high prolactin. Tested with prolactin.

  • Non-classical congenital adrenal hyperplasia (NCAH). Tested with a morning 17-OH progesterone, taken early in the cycle.

  • Premature ovarian insufficiency. Tested with FSH and estradiol early in the cycle. In more complex cases, AMH can also be helpful here.

  • Hypothalamic amenorrhea. Tested with FSH, LH, estradiol, along with a thorough look at stress, nutrition, and exercise.

  • Cushing’s syndrome. When there are signs pointing toward it, we use specific cortisol testing to rule it out.

  • Androgen-secreting tumours. These are rare, but worth considering when androgen symptoms come on quickly or testosterone levels are very high.

  • Post-pill changes. If you’ve recently come off birth control, your body needs time to find its rhythm again. I recommend waiting at least 3 months before testing.

If you want to learn more about each of these conditions and why they’re so easily confused with PCOS, check out my post, Is It Really PCOS (PMOS)?

Step 3: Looking at the Driving Factors

Once we know it’s PCOS (PMOS), the next question is what are the major factors driving it. As I talked about in The Real PCOS Types, you can have one, some, or ALL of these factors at once, and each one we find changes how we treat it.

Not all of these factors can be tested for unfortunately. However, the biggest gap I do see in testing is that metabolic health is almost always left out of the equation. 

Metabolic health and insulin resistance. Since this is the biggest gap I see, I want to spend a moment here. Metabolic screening is standard of care in PCOS (PMOS). Every single person with PCOS should be screened, regardless of their weight. I see so many people in the ‘lean PCOS’ category who have never had their blood sugar or insulin looked at, because they were told they didn’t “look” insulin resistant. A metabolic workup should include:

Inflammation. Inflammation is a key driver of PCOS (PMOS) for many people, so I like to include inflammatory markers like hs-CRP.

Adrenal function and chronic stress. DHEAS from Step 1 gives us some insight here, along with a careful look at your stress, sleep, and energy. More on cortisol testing below!

Depending on your symptoms: If you have regular cycles and deal with things like PMS, spotting, or trouble conceiving, I’ll sometimes test estrogen and progesterone in the luteal phase, which is the week or so before your period. This isn’t part of a standard PCOS workup. Low progesterone is common in PCOS (PMOS), though, and addressing it can make a real difference in day-to-day symptoms and in fertility. And while PCOS itself isn’t associated with painful periods, I do see higher rates of endometriosis and PMDD in my PCOS patients. If that sounds like you, it deserves its own attention.

The Test That’s Less Useful Than You’d Think: Cortisol

This one surprises people! Stress and adrenal involvement are real factors in PCOS (PMOS), so it makes sense that people want their cortisol tested.

The problem is that a single serum (blood) cortisol test gives us a pretty limited picture of how your stress response is actually functioning. I’ve had so many patients who feel absolutely awful, and then their blood cortisol comes back looking completely normal.

So here’s how I approach it:

  • If someone has signs of Cushing’s, I’ll test specifically to rule that out.

  • If I strongly suspect stress is a big part of someone’s PCOS picture, we’ll often just treat it. Alternatively, if we want more data, I prefer a 4-point salivary or urine cortisol test. It shows how cortisol rises and falls across the day, which is much more informative than a single blood draw.

The Full Panel at a Glance

Here’s everything in one place, so you can compare it to your own results:

Confirming the diagnosis: Total testosterone, SHBG, DHEAS, androstenedione (in some cases), AMH (adults, if needed) 

Ruling out look-alikes: TSH (plus a fuller thyroid panel if needed), prolactin, 17-OH progesterone, FSH, LH, estradiol, and Cushing’s testing if indicated

Driving factors: Hemoglobin A1C, fasting glucose & insulin or a 2-hour insulin glucose challenge, lipid panel, liver enzymes, hs-CRP

Depending on symptoms: Luteal phase estrogen and progesterone, and 4-point salivary or urine cortisol

A note on timing: If you get regular or semi-regular periods, I run hormones early in the cycle, ideally on cycle days 2 to 5, when results are easiest to interpret. A random blood draw in the middle of your cycle can make hormone results really hard to read.

Where to Go From Here

If you’ve been diagnosed with PCOS (PMOS), or suspect you might have it, here’s what I’d suggest:

Step 1: Check how you were diagnosed. Did you meet two of the three Rotterdam criteria, or was it an ultrasound alone?

Step 2: Make sure the look-alike conditions have been ruled out, and that the testing for them was actually done.

Step 3: Confirm you’ve had a full metabolic assessment, no matter what your weight is.

Step 4: Talk to your GP if you’re not sure what’s been tested. Ask for a copy of your results so you can compare them to the list above!

In our clinic, this comprehensive evaluation is ALWAYS the first step for anyone diagnosed with or suspected of having PCOS (PMOS). We confirm the diagnosis, rule out everything else, and figure out exactly which factors are at play. That way, we’re choosing treatment based on what’s actually going on for you, rather than guessing.

Ready to make a change?

If you want to know whether your PCOS (PMOS) has been fully worked up, or you’re ready to get to the bottom of what’s driving your symptoms, feel free to reach out to the clinic or book a complimentary consult with me here.

With loving compassion,

Dr. Alessia Milano, ND

Book Now

Frequently Asked Questions About PCOS Lab Testing

What blood tests should be included in a PCOS (PMOS) workup?

A comprehensive PCOS workup may include total testosterone, SHBG, DHEAS and, in some cases, androstenedione. Additional testing is often used to rule out other conditions and assess metabolic health, including TSH, prolactin, 17-OH progesterone, A1C, fasting glucose and insulin, a lipid panel, and liver enzymes. The exact testing needed depends on your symptoms and health history.

Can PCOS (PMOS) be diagnosed with an ultrasound alone?

No. PCOS is generally diagnosed when two of three criteria are present: irregular or absent periods, clinical or biochemical signs of elevated androgens, and polycystic ovarian morphology on ultrasound or, in adults when appropriate, elevated AMH. Other conditions that can cause similar symptoms also need to be considered.

What conditions can be mistaken for PCOS (PMOS)?

Several conditions can cause symptoms that overlap with PCOS, including hypothyroidism, hyperprolactinemia, non-classical congenital adrenal hyperplasia, premature ovarian insufficiency, hypothalamic amenorrhea and, less commonly, Cushing’s syndrome or androgen-secreting tumours.

Should insulin be tested if I have PCOS (PMOS) but I'm not overweight?

Metabolic health is important to assess in people with PCOS regardless of body weight. Testing may include A1C, fasting glucose and insulin or a two-hour glucose and insulin challenge, along with a lipid panel and liver enzymes.

When is the best time in my cycle to have PCOS hormone testing done?

If you have regular or semi-regular periods, hormone testing is often done early in the menstrual cycle, ideally around cycle days 2 to 5. Timing matters because hormone levels naturally change throughout the cycle and can affect how results are interpreted.

Why can PCOS symptoms occur even when bloodwork is “normal”?

PCOS symptoms can still be present even when basic bloodwork falls within the normal range. A standard panel may not include the full range of hormones, metabolic markers, or tests needed to understand what may be contributing to your symptoms. Results also need to be interpreted alongside your menstrual cycle, symptoms, health history, and other diagnostic criteria—not in isolation.

 
Hormones, PCOS, PMOSDr. Alessia Milano NDThe Clara Clinic