PCOS Hormone Blood Test
Are irregular periods, acne, or weight fluctuations causing concern? This profile checks 7 key hormones often imbalanced in Polycystic Ovary Syndrome, helping you understand what's happening hormonally and take the right next steps.
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Results in 2-3 days
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Get a clear snapshot of your health without the hassle. We’ll send the kit and instructions
How it works
Book a home visit
A health professional takes your sample at home or work
From £65
Book a clinic
Professional blood draw at a nearby partner clinic.
From £40
Free tracked return
Post your kit in any Royal Mail postbox with the pre-paid, tracked label.
Doctor-written report
Every Brooksby Medical result is written and reviewed by a GP. You’ll get plain-English explanations for each marker and clear next steps.
Dr James Coleman, MBChB, MRCGP
Founder & GP, Brooksby Medical
Every report is personally reviewed with clear, actionable advice.
Data secure • UKAS-accredited labs • Doctor-led care
What’s measured in this test
Each biomarker helps reveal insights into your health.
DHEA Sulphate
What is DHEA sulphate (DHEA-S)
DHEA-S is a hormone made mainly by the adrenal glands. It is a source of androgens, which can affect hair growth, skin, and the menstrual cycle.
What a high result might mean
High levels can happen with polycystic ovary syndrome or non-classic congenital adrenal hyperplasia. Very high levels, especially with fast-changing symptoms such as deepening voice or rapid hair growth, can rarely be caused by a hormone-producing growth and need urgent specialist review.
What a low result might mean
Levels fall naturally with age. Low levels can also be seen if the adrenal glands or the pituitary gland are underactive. Your clinician will interpret this alongside your symptoms and other tests.
Prolactin
What is prolactin?
Prolactin is a hormone made by the pituitary gland. It helps control breast milk production and affects periods, fertility and sexual function. Levels can rise with stress, sleep and during pregnancy.
What a high result might mean
A raised result is common and often caused by medicines or thyroid or kidney problems. Sometimes it is due to a small growth on the pituitary gland called a prolactinoma. Your doctor will repeat the test, review any medicines, and may arrange a scan if it stays high or if there are symptoms such as headaches or changes in vision.
What a low result might mean
A low level is usually related to treatment with medicines that lower prolactin or to reduced pituitary function. On its own it rarely needs treatment, but your clinician will check other pituitary hormones if needed.
Follicle Stimulating Hormone
What is follicle stimulating hormone (FSH)
FSH is made by the pituitary gland in the brain. It stimulates the ovaries to grow follicles, which contain eggs, and helps regulate the menstrual cycle.
What a high result might mean
High FSH can mean the ovaries are not responding well, which happens naturally after menopause or earlier in conditions such as premature ovarian insufficiency. It can also rise after some medical treatments affecting the ovaries.
What a low result might mean
Low FSH can occur if the brain is not sending enough signals to the ovaries, often due to stress, significant weight loss, or excessive exercise. Hormonal contraception also lowers FSH levels while in use.
Luteinising Hormone
What is luteinising hormone (LH)
LH is made by the pituitary gland in the brain. It helps control the menstrual cycle and triggers ovulation — the release of an egg from the ovary.
What a high result might mean
High LH levels are normal around ovulation or after menopause. In younger women, they can suggest polycystic ovary syndrome or, if both LH and FSH are high, reduced ovarian function.
What a low result might mean
Low LH may mean the brain is not sending enough signals to the ovaries, often due to stress, weight loss, or excessive exercise. Some medicines and hormone treatments can also lower LH levels.
Free Androgen Index
What is the Free Androgen Index (FAI)?
The Free Androgen Index (FAI) is a calculation that estimates how much testosterone in your blood is active. It is worked out by comparing your total testosterone level with the amount bound to a protein called SHBG. This gives an indication of how much hormone is available for your body to use.
What a high result might mean
A high FAI can mean that your body is producing or taking in too much testosterone. It may be linked to anabolic steroid use or, rarely, to hormone-producing growths in the testicles or adrenal glands. In some cases, a low SHBG level can make the FAI appear higher than it really is.
What a low result might mean
A low FAI suggests that the amount of active testosterone may be reduced. This can occur if the testicles are not making enough hormone, or if SHBG levels are high due to age, liver or thyroid problems, or some medicines. Your doctor may repeat the test or calculate your free testosterone for a more accurate picture.
Sex Hormone Binding Globulin
What is sex hormone binding globulin (SHBG)
SHBG is a protein made by the liver that carries hormones such as testosterone and oestrogen through the blood. It controls how much of each hormone is free and active in the body.
What a high result might mean
High SHBG is common during pregnancy, with the pill, or HRT, and in thyroid overactivity. It may also rise with liver conditions or in people who are naturally thin.
What a low result might mean
Low SHBG can be linked with being overweight, insulin resistance, or polycystic ovary syndrome. It means more active hormone is available in the body, which can cause symptoms like acne or unwanted hair growth.
Testosterone
Testosterone
Testosterone is a hormone that helps regulate sex drive, maintain bone strength, control fat distribution, support muscle growth, and stimulate the production of red blood cells and sperm.
In men, most testosterone is produced in the testicles. In women, smaller amounts are made in the ovaries and adrenal glands.
Men’s testosterone levels naturally decline after about age 30, but low levels can occur at any age and may cause symptoms such as reduced libido, erectile dysfunction, tiredness, loss of muscle mass, and low energy.
Although women have much lower testosterone levels than men, testosterone still supports libido, muscle tone, and red blood cell production.
Laboratory reference ranges vary. Guidance from the British Society for Sexual Medicine notes that testosterone may be considered low if it falls below the normal range, or around 12 nmol/L in men who have symptoms suggestive of testosterone deficiency.
Frequently asked questions
What is Polycystic Ovary Syndrome (PCOS)?
Polycystic Ovary Syndrome (PCOS) is a common hormone imbalance where periods can be irregular and levels of androgens (often called 'male hormones') are frequently higher. It’s also often connected with issues like insulin resistance and weight changes.
What is PCOS?
Polycystic Ovary Syndrome (PCOS) is a common hormonal condition affecting 1 in 10 women. It's characterized by irregular periods, elevated androgens (male hormones), and can affect fertility, metabolism, and long-term health. Blood tests help identify the hormonal patterns typical of PCOS.
Who should consider the PCOS Hormone test?
This test is useful for women experiencing:
Irregular or absent periods
Acne or oily skin
Excess hair growth (face, chest, back)
Weight gain or difficulty losing weight
Fertility challenges
What are the common symptoms?
Symptoms can include irregular or absent periods, unwanted facial or body hair, acne or oily skin, weight gain (often around the middle), thinning hair on the scalp, low mood or low energy, and challenges when trying to conceive.
What hormones are measured in the PCOS profile?
The profile checks 7 key hormones:
Testosterone - often elevated in PCOS
SHBG & FAI - shows free testosterone levels
LH & FSH - pituitary hormones affecting ovulation
DHEAS - another androgen marker
Prolactin - can affect cycles
Why does a clear diagnosis matter for fertility and long-term health?
A diagnosis helps you plan for pregnancy and, if needed, gives you the right information to time fertility treatments. It also helps flag important longer-term health risks like type 2 diabetes and high cholesterol, so you can take preventative steps early.
When should I take the PCOS test during my cycle?
Ideally, test on day 2-5 of your menstrual cycle for the most accurate hormone assessment. If you have irregular or absent periods, you can test at any time.
Who should consider this test?
This test is for anyone who has symptoms that might suggest PCOS—or someone who has been diagnosed and wants a detailed, up-to-date look at their:
Hormone balance
Egg reserve (fertility potential)
Blood sugar control
Cholesterol levels
The influence of their thyroid and adrenal hormones
How should I prepare for the PCOS test?
Preparation steps:
Timing: Day 2-5 of cycle if possible
No fasting required
Be well: Avoid testing during illness
Hydrate: Drink water beforehand
Bring ID: Photo ID and order confirmation
What can this test show?
This test helps your doctor look for:
PCOS Hormone Patterns: Levels of key hormones like testosterone and related markers (SHBG, free androgen index, LH, and FSH).
Egg Reserve: Your potential fertility is assessed using the Anti-Müllerian hormone (AMH).
Other Influences: We check your thyroid control (TSH) and look at hormones from your adrenal glands (cortisol and DHEA sulphate) that can sometimes affect PCOS symptoms.
Heart & Metabolic Health: We measure your average longer-term blood sugar (HbA1c), a same-day glucose, and provide a full cholesterol profile to assess heart health risk.
Do I need to fast?
No, fasting isn’t required. This test uses markers for long-term blood sugar control (HbA1c) and a random glucose reading, so you can eat normally beforehand.
How will I receive my PCOS results?
Secure online results with a GP-written explanation from Brooksby Medical in 2–3 working days.
When should I collect my sample?
Morning (6–10 am) is best for the most stable hormone readings.
If your periods are regular, testing on days 2–5 gives the most useful information about your LH and FSH levels.
If your periods are irregular or absent, you can test on any day.
What happens if my results suggest PCOS?
We explain the hormonal patterns and recommend next steps, which typically include GP referral for clinical diagnosis (often including ultrasound) and discussion of management options including lifestyle, medication, or specialist care.
I’m on hormonal contraception — does it affect results?
Yes, hormonal contraceptives (like the pill) can change your readings for several hormones (LH, FSH, testosterone, and SHBG). If you need a picture of your natural hormone levels (e.g., for diagnosis), consider testing after your natural cycles have returned following a break. Please do not stop taking any prescribed contraception without medical advice.
How will I receive my results?
You will receive secure online results with a GP-written explanation from Brooksby Medical in 3–5 working days.
What happens if something is abnormal?
We will clearly explain what the result may mean and advise you on the practical next steps. This may include suggesting lifestyle changes, follow-up tests, or a referral to your GP.
How to Prepare for Your Test
Timing & General Health
Be Well: Take your sample only when you are feeling well. Avoid testing during short-term illnesses (like a cold or flu) as this can temporarily affect hormone levels.
Best Time: Collect your sample between 6:00 AM – 10:00 AM. This morning window is crucial for getting the most stable and accurate hormone readings.
Supplements & Hydration
Hydrate: Drink plenty of water in the hours leading up to your appointment. Being well-hydrated makes the blood sample collection process easier and smoother.
Avoid Biotin: Unless instructed by your doctor, stop taking any biotin supplements for 48 hours before your test. Biotin can interfere with the lab's ability to accurately measure some hormones.
Medication
Thyroid Medication Timing:
If you take desiccated thyroid extract or liothyronine, please take your dose after your blood sample has been collected.
If you take levothyroxine, you can take it as usual before your appointment.Contraception: (This relates to the timing/results FAQ, but important to reiterate if you're including it on the prep page): If you are taking hormonal contraception, it may affect certain hormone levels. Please check the FAQs for more details.
Your Appointment
What to Bring: Make sure to bring your photo ID and your order confirmation email to your appointment.
Related reading
Articles from our GP that relate to this test - explaining your results, what they mean, and when to take action.
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