Polycystic ovary syndrome, or PCOS, is one of the most common hormonal conditions affecting women of reproductive age. Sadly, many women go undiagnosed, receive late diagnosis, or get misdiagnosed entirely. In fact, the latest studies show that 4 to to 20% of women worldwide have PCOS, but up to 70% of those affected don’t even know it.

The symptoms of PCOS vary widely from one person to another, and there’s no single test to confirm it on its own. However, several important blood tests help identify hormone imbalances, metabolic risks, and related conditions. While these tests don’t diagnose PCOS on their own, they provide critical results that support an accurate diagnosis and help plan for future health.

In this guide, you’ll learn:

• Which blood tests are used for PCOS diagnosis

• What a hormone panel for PCOS typically includes

• How results are interpreted

• How to prepare for testing

• What to do next after you get your results

What is PCOS and How Is It Diagnosed?

PCOS is characterized by a combination of symptoms, including menstrual cycles, excessive hair growth, and polycystic ovaries. It is diagnosed based on those symptoms, plus imaging results and lab tests. Most doctors follow the Rotterdam criteria, which require at least two of the following:

• Irregular or absent menstrual cycles

• Clinical or biochemical signs of excess androgens or hyperandrogenism

• Ultrasound findings of Polycystic-appearing ovaries

Why Blood Tests Matter for PCOS

PCOS affects more than reproductive hormones. It can also lead to complications, such as infertility, metabolic issues, and an increased risk of conditions like type 2 diabetes and heart disease. 

This is why early diagnosis of PCOS is important. A series of initial blood tests helps your doctor:

• Detect elevated androgens that may not be obvious on physical exam

• Identify insulin resistance early

• Rule out other hormonal disorders, such as thyroid or adrenal conditions

• Establish a baseline for monitoring over time

Core Hormone Panel for PCOS

A hormone panel for PCOS focuses on reproductive and androgen hormones that are often altered in this condition. The key markers include:

1. LH and FSH

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) play crucial roles in regulating ovulation. For many women with PCOS, LH levels are higher while FSH levels are lower. While the LH-to-FSH ratio alone does not diagnose PCOS, it can support other clinical findings.

Read more: LH vs FSH: Understanding Health Markers

2. Total and Free Testosterone

Elevated testosterone levels are one of the most common signs of PCOS. Measuring free testosterone is usually more informative than measuring total testosterone. Higher levels of testosterone can lead to symptoms, such as acne, excess hair growth, and hair thinning.

3. DHEA-S and Androstenedione

These are hormones from your adrenal glands. High levels of DHEA-S and Androstenedione may indicate that the issue originates in the adrenal glands rather than your ovaries. Measuring these markers helps to identify the source of excess androgen.

4. SHBG (Sex Hormone-Binding Globulin)

SHBG is a protein that binds to circulating sex hormones. In PCOS, SHBG levels are often lower, which increases the amount of active testosterone. Low SHBG levels are usually linked to insulin resistance.

5. Estradiol and Progesterone

Estradiol shows estrogen activity in the body, while progesterone levels help determine whether ovulation is happening. Together, these hormones provide important context for any menstrual irregularities you might be experiencing.

Read more: SHBG vs DHEA-S: Understanding Health Markers

Metabolic Blood Tests for PCOS

PCOS is closely linked to metabolic health. Many people with PCOS have insulin resistance even if their weight is within a normal range.

1. Fasting Glucose and Fasting Insulin

These tests are important for screening for PCOS. High fasting insulin levels can appear before blood sugar levels rise. It helps doctors catch insulin resistance early.

2. HbA1c

The HbA1c test measures your average blood glucose levels over the past two to three months. It’s great for assessing long-term glucose control and supports the early detection of prediabetes risk.

3. Lipid Panel

This test checks your total cholesterol, LDL (low-density lipoprotein), HDL (high-density lipoprotein), and triglycerides. Women with PCOS have less-than-ideal lipid profiles, so these markers help evaluate long-term cardiovascular risk.

Additional Blood Tests That Support PCOS Diagnosis

These tests are often included to rule out other conditions that mimic PCOS.

1. Thyroid Panel (TSH, Free T4)

Thyroid dysfunction can lead to irregular periods and weight changes. Normal results from this panel help to confirm that the symptoms are not related to thyroid issues.

2. Prolactin

High levels of prolactin can disrupt ovulation. This test is essential for excluding pituitary causes of menstrual irregularities.

3. 17-Hydroxyprogesterone

This test is used to rule out non-classical congenital adrenal hyperplasia, particularly when androgen levels are significantly elevated. 

What Blood Test Results for PCOS Typically Show

Why Normal Results Don’t Always Rule Out PCOS

Normal test results don't always mean you don't have PCOS. That's because hormones can change significantly during your menstrual cycle and across different life stages. Just one test might not give the full picture.

A few things that can influence your results include:

• Cycle timing

• Any recent weight changes

• Stress

• Hormonal medications

Some people with PCOS can actually have normal hormone levels at times. Doctors diagnose PCOS by looking at patterns over time, including symptoms, medical history, imaging, and follow-up tests—it's not just about one lab result.

When to Schedule PCOS Blood Tests?

Timing matters for accurate interpretation.

• Early cycle testing: It's usually recommended to do hormone tests on days 2 to 5 of your menstrual cycle.

• Progesterone testing: This is typically done later in your cycle to check if you've ovulated.

• Fasting tests: For tests like glucose, insulin, and lipid panels, you'll need to fast for about 8 to 12 hours beforehand.

If your cycles are irregular, your doctor might suggest testing at a consistent time each month.

How to Prepare for a PCOS Blood Test

If you’re getting ready for a PCOS blood test, here are some simple tips to keep in mind for the best results:

• Make sure to follow any fasting instructions you get.

• Let your doctor know about any supplements or medications you’re taking. Don’t stop any prescribed medications without talking to your doctor first.

• Try to avoid intense workouts the day before your test.

• Check with your provider if hormonal birth control could impact the test results.

Blood Tests vs Ultrasound in PCOS Diagnosis

Blood tests and ultrasounds serve different purposes in diagnosing PCOS. Blood panels help reveal hormone levels and metabolic patterns, while ultrasounds assess ovarian structure.

Some women can be diagnosed with PCOS even if their ovaries don’t look polycystic on scans. Others may have polycystic-appearing ovaries but don’t show any hormonal issues. That’s why doctors use both imaging and symptoms to make a complete diagnosis, rather than relying on just one.

What Happens After PCOS Diagnosis?

There is no single cure for PCOS, but there are effective ways to manage symptoms and reduce long-term health risks. Treatment depends on your goals, whether that’s regulating periods, improving skin symptoms, supporting fertility, managing weight, or reducing metabolic risk.

PCOS treatment is typically personalized and may include lifestyle strategies, medications, and ongoing monitoring.

Use Blood Testing to Take Control of PCOS

Diagnosing PCOS can be tricky, but testing your hormones and other related blood markers can make things clearer. A comprehensive hormone panel for PCOS not only supports diagnosis but also helps identify hormone imbalances, metabolic risks, and long-term health priorities.

If you’re experiencing symptoms of PCOS or want a clearer view of your hormonal health, comprehensive blood testing is a practical first step. Mito Health offers a clinically guided Core Comprehensive Panel that evaluates 100+ biomarkers, including:

• Reproductive hormones

• Androgens and SHBG

• Thyroid markers

• Fasting insulin and glucose

• Lipid profile

• Inflammatory markers

• Nutrient status

• Liver and kidney function

Your results are reviewed by top doctors, helping you understand what they mean and what to do next.

Frequently Asked Questions

• Do I need all these tests to diagnose PCOS?
  Not always. Testing is individualized based on your symptoms, medical history, and clinical findings. Some people require a full hormone and metabolic panel, while others need more targeted testing.

• Can PCOS blood tests change over time?
  Yes. Hormone and insulin levels can change with age, weight, lifestyle, and treatment.
  
  

• What is the best time in my cycle to test for PCOS?

Most reproductive hormone tests (LH, FSH, estradiol) are measured during the early follicular phase, typically cycle days 2 to 5. If your cycles are irregular, your clinician may choose a standardized timing strategy. Fasting insulin and metabolic tests can usually be done on any day.

• Can I test while on birth control?
  Hormonal contraception can affect hormone levels, especially testosterone, SHBG, LH, and FSH. Your clinician may recommend testing off hormonal birth control for a clearer interpretation. Never stop medication without medical guidance.

• Can you have PCOS with normal testosterone levels?

Yes. Not everyone with PCOS has high testosterone on blood work. Some have clinical signs of excessive androgen without abnormal lab values. Diagnosis is based on overall patterns of symptoms, menstrual history, ultrasound findings, and metabolic markers, not a single hormone result.

Resources:

• https://doi.org/10.1016/j.endmts.2025.100228

• https://www.who.int/news-room/fact-sheets/detail/polycystic-ovary-syndrome

• https://www.ncbi.nlm.nih.gov/books/NBK459251

• https://pmc.ncbi.nlm.nih.gov/articles/PMC7520057

• https://pmc.ncbi.nlm.nih.gov/articles/PMC11592971

• https://www.sciencedirect.com/science/article/pii/S102845591930107X