Published April 2026 | Blood testing for PCOS in Plymouth

PCOS Blood Testing: Understanding Your Results

Polycystic ovary syndrome (PCOS) is one of the most common hormonal conditions, affecting around 1 in 10 women of reproductive age. Yet many people live with PCOS for years without a diagnosis, often putting their symptoms down to stress or weight gain.

If you’re experiencing irregular periods, unexplained weight gain, persistent acne, excess hair growth, hair loss, or difficulty conceiving, PCOS could be worth investigating. Blood tests play an important role in understanding what’s happening with your hormones and ruling out other conditions that can cause similar symptoms.

At Tamar Health in Plymouth, we offer comprehensive PCOS screening with results available within 1–3 working days. This guide explains what our PCOS blood tests include, what your results can reveal, and how they help guide your next steps.

What is PCOS and Why Does It Matter?

PCOS is a condition where your ovaries may produce higher levels of male hormones (androgens) than typical. This can disrupt your menstrual cycle and affect fertility. It’s also commonly linked to insulin resistance, which can contribute to weight gain and increase your risk of type 2 diabetes over time.

The challenge with PCOS is that there’s no single test that diagnoses it. Instead, doctors use the Rotterdam criteria—a combination of clinical features, ultrasound findings, and blood results. That’s why blood testing matters: it’s one essential piece of the puzzle.

Why Blood Tests Matter for PCOS

If you suspect PCOS, blood work serves several important purposes:

• Confirm hormonal patterns: The balance of hormones like LH and FSH, alongside high testosterone, can help identify androgen excess—a key feature of PCOS.
• Rule out other conditions: Thyroid problems, elevated prolactin, or adrenal issues can mimic PCOS symptoms. Blood tests help distinguish between them.
• Assess insulin resistance: Many people with PCOS have insulin resistance, even if they’re not overweight. Testing your fasting glucose, insulin, and HbA1c shows whether this is affecting you.
• Understand your ovarian reserve: If fertility is important to you, AMH testing reveals how many eggs your ovaries have—useful information for planning.
• Guide treatment: Whether you’re considering medication, lifestyle changes, or fertility support, knowing your exact hormone and metabolic picture helps your doctor create a plan that’s right for you.

Our PCOS Testing Options

PCOS Screen — £185 all-inclusive

Our standard PCOS Screen is designed to give you a comprehensive view of the hormones and metabolic markers most relevant to PCOS:

• Pituitary hormones: LH and FSH (the ratio between these is a key PCOS marker)
• Androgens: total testosterone, free androgen index (FAI), and DHEA-S to assess androgen excess
• SHBG: sex hormone-binding globulin (often low in PCOS)
• Prolactin: to rule out prolactin-related conditions
• Oestradiol: oestrogen levels
• Thyroid function: TSH and free T4 (important because thyroid problems can look like PCOS)
• Metabolic markers: fasting glucose, insulin, and HbA1c (to check for insulin resistance)
• Full blood count: overall health snapshot

PCOS Screen with AMH — £235 all-inclusive

Choose this option if you want everything in the standard screen plus:

• AMH (anti-Müllerian hormone): This reflects your ovarian reserve—the number of eggs your ovaries contain. AMH is typically elevated in PCOS, and testing it is especially useful if you’re thinking about fertility or want to understand your reproductive timeline.

What Your Results Can Show

Androgen Excess

Elevated testosterone or a high free androgen index (FAI) can help identify androgen excess—a hallmark of PCOS. Your SHBG level matters too: when SHBG is low, more testosterone circulates freely, contributing to symptoms like acne, facial hair growth, and scalp hair loss.

The LH:FSH Ratio

In people without PCOS, LH and FSH follow a specific pattern across your cycle. In PCOS, the LH:FSH ratio is often higher than expected, reflecting disrupted communication between your pituitary gland and ovaries. This imbalance can explain irregular or missing periods.

Insulin Resistance

Fasting glucose and insulin levels show how well your body handles sugar. If fasting insulin is elevated even when glucose is normal, insulin resistance may be present—something that affects up to 70% of people with PCOS. HbA1c gives a 3-month average of blood sugar, showing your longer-term metabolic health.

Ovarian Reserve (AMH)

AMH correlates with the number of eggs in your ovaries. In PCOS, AMH is typically higher than in people without PCOS. If you’re thinking about freezing eggs, assessing fertility, or understanding your reproductive window, this marker is valuable.

Ruling Out Other Causes

Your thyroid function (TSH and free T4) and prolactin levels are essential. Thyroid disease and hyperprolactinaemia can cause irregular periods, weight gain, and hair changes that mimic PCOS. Testing these ensures you’re not missing another diagnosis.

Who Should Consider PCOS Blood Testing?

Consider booking a PCOS screen if you have:

• Irregular, infrequent, or absent periods
• Unexplained weight gain or difficulty losing weight
• Acne that doesn’t improve with standard skincare
• Excess body hair (hirsutism) or male-pattern hair loss
• Difficulty conceiving
• A family history of PCOS or type 2 diabetes
• Symptoms of insulin resistance (dark skin patches, cravings for carbs, energy crashes)

You don’t need to have all these symptoms—even a few warrant investigation. PCOS is a spectrum condition, and early detection makes management easier.

Timing Your Blood Test

For the most accurate results, PCOS blood tests are ideally taken on days 2–5 of your menstrual cycle. This is when LH, FSH, and oestradiol levels are most stable and interpretable.

However, if your cycles are irregular or absent, you can have your blood test any day—your doctor will interpret the results with that in mind.

What Happens After Your Appointment

Before your visit: Book your appointment online. A £25 appointment fee is payable at booking; the remaining balance is due when you attend the clinic.

At the clinic: One of our trained phlebotomists will take a small blood sample. The appointment is quick and straightforward.

After testing: Your blood is processed by our lab partner, Nationwide Pathology (UKAS-accredited). You’ll receive your results within 1–3 working days via your online account or email. Results include reference ranges and brief explanations to help you understand them.

Next steps: Book a follow-up consultation with your GP or a specialist (such as a gynaecologist or endocrinologist) to discuss what your results mean and plan any next steps—whether that’s lifestyle changes, medication, dietary adjustments, or fertility planning.

Frequently Asked Questions

Do I need to fast before my PCOS blood test?

Yes. For accurate fasting glucose and insulin measurements, please avoid food and drink (except water) for 10–12 hours before your appointment. It’s best to book a morning slot so fasting is easier.

Can I take this test if I’m on hormonal contraception?

Hormonal contraception can affect some hormone levels (like testosterone and SHBG). If you’re considering testing while on contraception, discuss this with your GP first. Some doctors prefer to see results off hormonal contraception for clearer interpretation, while others test you as you are. Either approach is valid—your doctor will advise based on your situation.

How accurate is a PCOS blood test?

Blood tests are accurate at measuring hormone and metabolic levels. However, no single test diagnoses PCOS. Your results are most meaningful when combined with your symptoms, ultrasound findings, and clinical assessment. That’s why seeing a healthcare professional to interpret your results is important.

Will blood tests tell me if I can get pregnant?

Not definitively. AMH gives an estimate of ovarian reserve (egg quantity), but it doesn’t predict fertility or the quality of your eggs. Many people with PCOS and low AMH conceive naturally, while others with high AMH may face challenges. Blood tests are one tool; fertility is complex and individual. If you’re concerned about conception, talk to your GP or a fertility specialist.

What if my results are normal?

Normal blood results don’t rule out PCOS—the condition is diagnosed using the Rotterdam criteria, which includes ultrasound and clinical features. If you have typical PCOS symptoms but your blood work is normal, that’s still useful information. It might prompt your doctor to look more closely at other factors or suggest lifestyle support. Don’t hesitate to discuss your results with your healthcare provider.

Taking the First Step

If you think PCOS might be affecting your health, blood testing is a practical, straightforward way to gather important information. Our PCOS screens are designed to give you clarity on your hormones, metabolic health, and ovarian reserve—all at a fixed, transparent price with fast results.

Understanding your body is the first step to managing your health confidently. Whether you’re looking to regulate your cycle, support your metabolism, or plan for fertility, knowing your numbers empowers you and your doctor to make informed decisions.

Disclaimer: This blog is for informational purposes only and is not a substitute for medical advice. Blood tests are one part of PCOS diagnosis and management. Please consult your GP or specialist to discuss your symptoms and results. Tamar Health provides blood testing services; we do not diagnose conditions.