What PCOS Tests Should You Order?

PCOS Lab Tests

A Simple Guide to the Essential Labs

Every week, I sit with women who are frustrated, discouraged, and tired of being told the only answer for their PCOS is the birth control pill. They want real support. They want clarity. They want a plan that actually fits their body.

A common pattern keeps showing up.

Most of these women haven’t even had the right testing done.

Without proper labs, you can’t see the full picture. You can’t understand where the imbalance is coming from. And you certainly can’t build a personalized treatment plan that supports hormones, metabolism, and long-term health.

Basic labs miss the patterns that define PCOS. One hormone check can’t show how the ovaries, adrenals, thyroid, and metabolic system are interacting. PCOS isn’t diagnosed from a single marker. It’s a constellation of symptoms, hormone shifts, and metabolic clues that often get overlooked in a quick appointment.

This is usually the moment everything clicks for my patients.

Once we test the right markers and review them together, the confusion lifts. You finally see what your body has been trying to tell you. And from there, treatment becomes more focused, more effective, and far less overwhelming.

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The Core PCOS Hormone Tests

Total and Free Testosterone

These are the main markers for androgen excess. Total testosterone shows what the ovaries are producing. Free testosterone shows what is active in the body.

High levels can explain acne, chin hair, hair thinning, and irregular ovulation. Free testosterone is often elevated even when total testosterone looks normal.

DHEA-S

DHEA-S comes from the adrenal glands. High levels point to adrenal involvement or chronic stress patterns. It also helps differentiate ovarian androgen excess from adrenal-driven symptoms.

LH and FSH

These two hormones show how well the brain is communicating with the ovaries. Many women with PCOS have a higher LH relative to FSH, which can interfere with ovulation. A ratio above 2 to 1 can suggest PCOS, but not every woman will show this pattern. A normal ratio does not rule anything out.

AMH (Anti-Müllerian Hormone)

AMH reflects the number of small follicles sitting in the ovaries. Higher levels often match the “string of pearls” that shows up on ultrasound. It does not predict fertility. It does help identify PCOS patterns, especially when cycles are irregular or ultrasound is not possible.

Tests to Rule Out Other Conditions

Thyroid Panel: TSH, Free T4, Free T3, Antibodies

Thyroid issues mimic PCOS symptoms, so a full thyroid panel is essential. Many women have thyroid antibodies long before TSH changes. I always include antibodies because they tell us if the immune system is affecting the thyroid.

Prolactin

High prolactin can stop ovulation and cause the same pattern of irregular cycles. It must be ruled out before diagnosing PCOS.

17-Hydroxyprogesterone

This screens for non-classic congenital adrenal hyperplasia, a less common condition that can look almost identical to PCOS.

hCG when periods are absent

If cycles are missing, pregnancy must be ruled out first.

Insulin and Blood Sugar Testing

Fasting Insulin

This is one of the most important tests for PCOS. Insulin resistance is present even in lean women and is often the real driver behind high testosterone, weight gain, and cycle disruption.

Fasting Glucose

Glucose changes later than insulin. A normal glucose does not rule out insulin resistance.

HbA1c

Shows three-month blood sugar trends. Helpful for long-term metabolic risk.

HOMA-IR

A calculation based on fasting insulin and glucose. It helps show how hard the pancreas is working to keep blood sugar stable and tells you the degree of insulin resistance you have.

When to consider a 2-hour glucose tolerance test

I use this when fasting insulin looks normal but symptoms suggest insulin resistance. It can uncover early blood sugar issues long before A1c changes.

Metabolic and Cardiovascular Risk Labs

Cholesterol Panel: LDL, HDL, Triglycerides

PCOS increases the risk of metabolic and cardiovascular issues. Low HDL and high triglycerides show early insulin resistance. Higher LDL is also more common in PCOS.

Liver Enzymes to Assess Fatty Liver

ALT can screen for fatty liver, which is more common in women with PCOS, even if they have a normal BMI.

Inflammation and Nutrient Markers

hs-CRP

PCOS has an inflammatory component. High hs-CRP can explain fatigue, pain, weight loss resistance, or stubborn insulin resistance.

Ferritin

Low iron stores worsen fatigue, hair thinning, and exercise intolerance. High ferritin can reflect inflammation.

Vitamin D

Commonly low in PCOS and linked to insulin resistance, mood symptoms, and ovulation.

B12

Metformin, a medication sometimes used by medical doctors for high blood sugars can lower B12 levels over time. Low B12 can worsen fatigue, mood changes, and nerve-related symptoms

Optional Tests I Use Case by Case

Cortisol (AM)

Helpful when stress, burnout, or chronic inflammation are suspected. Not required for diagnosis but useful for treatment planning especially when long term stress has been present.

Progesterone (to confirm ovulation)

Timed around seven days after ovulation. Helpful when cycles are irregular and ovulation patterns are unclear.

Androstenedione

Useful when testosterone is normal but symptoms remain. Gives another look at androgen activity.

SHBG

Low SHBG is linked to insulin resistance and increases the amount of free testosterone.

How These Tests Fit Together

PCOS is not diagnosed by checking one hormone. It is diagnosed by seeing the full pattern. Androgens show us where the excess is coming from. LH and FSH show us how the brain and ovaries are communicating. Insulin markers show whether blood sugar issues are driving hormonal changes. Thyroid and prolactin rule out other causes of irregular cycles. Inflammation, cholesterol, liver markers, and nutrient levels show the bigger metabolic picture.

When all of this comes together, we can see your root drivers. That is what allows treatment to be personalized, effective, and sustainable.

Next Steps

PCOS becomes much easier to treat when you know what is actually happening in your body.

If you want a clear interpretation of your labs and a personalized plan, I am here to help.

I work with women virtually across Ontario who want real solutions, not guesswork.

Book a discovery call today, and take the first step toward getting the care and support you deserve.

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