Female Thyroid & Cortisol Test Kit | Specialist Doctor Report Included

Test ID: SB-640 | Saliva 4-Point Cortisol + Blood Spot Thyroid Panel

The Female Thyroid & Cortisol Test Kit is a comprehensive at-home hormone test designed specifically for women, measuring 10 key markers across thyroid function and the full daily cortisol rhythm. It combines a 4-point saliva cortisol profile with a full blood spot thyroid panel — providing a clinically meaningful picture of two of the most interconnected hormone systems in women’s health.

Thyroid dysfunction and cortisol dysregulation are among the most common and most frequently missed causes of persistent symptoms in women. They are also deeply interdependent: chronic cortisol elevation suppresses T3 conversion, mimicking hypothyroidism even when the thyroid gland itself is healthy. Conversely, thyroid insufficiency impairs the body’s stress resilience and disrupts the cortisol rhythm. Testing both together — as this kit does — is the most clinically complete approach available outside a hospital setting.

Test from home with confidence — no clinic visit required. Results within 3–5 working days.

Why This Test Is Particularly Important for Women

Women are 5–10 times more likely than men to develop thyroid disorders — and thyroid disease in women is frequently underdiagnosed or misattributed to stress, depression, or perimenopause. The relationship between thyroid hormones and the female hormonal system is direct and significant:

• Oestrogen and thyroid hormones are closely linked — rising oestrogen (during the cycle, pregnancy, or HRT) increases thyroid-binding globulin, reducing available free T3 and T4 and potentially triggering or worsening hypothyroid symptoms even when TSH appears normal
• Thyroid dysfunction disrupts the menstrual cycle — both hypothyroidism and hyperthyroidism can cause irregular, heavy, or absent periods; low thyroid function is a significant and overlooked cause of fertility problems in women
• Cortisol suppresses T3 conversion — under chronic stress, the body converts T4 to reverse T3 (rT3) rather than active T3; this produces hypothyroid-like symptoms (fatigue, weight gain, brain fog, low mood) with a normal TSH — detectable only when FT3 is measured alongside TSH and FT4
• Thyroid autoimmunity peaks in women — Hashimoto’s thyroiditis is the most common cause of hypothyroidism in women; TPO and Tg antibodies are the diagnostic markers, and many women carry elevated antibodies for years before TSH becomes abnormal
• Perimenopause and thyroid symptoms overlap significantly — fatigue, weight gain, brain fog, mood changes, and disrupted sleep are shared by both conditions; testing both thyroid and cortisol allows accurate differentiation

What This Test Measures

Blood Spot — Full Thyroid Panel

• TSH (Thyroid Stimulating Hormone): The pituitary signal to the thyroid. The standard first-line thyroid screen — but in women, TSH alone misses early thyroid dysfunction, antibody-positive Hashimoto’s, and cortisol-driven T3 suppression.
• Free T3 (FT3): The active thyroid hormone — the form that actually enters cells and drives metabolism, energy, mood, and temperature regulation. Low FT3 with normal TSH is one of the most common patterns in chronically stressed women and is the direct cause of hypothyroid symptoms.
• Free T4 (FT4): The thyroid’s main output hormone, converted to T3 in peripheral tissues. Low FT4 alongside normal TSH suggests early thyroid insufficiency or impaired conversion.
• Total T4 (TT4): Measures total circulating T4, including bound fraction. Useful for assessing the impact of oestrogen on thyroid hormone binding — particularly relevant for women on HRT or the contraceptive pill.
• TPO Antibodies (Anti-TPO): The primary marker of Hashimoto’s thyroiditis — the autoimmune condition responsible for the majority of hypothyroidism in women. Elevated TPO antibodies can be present for years before TSH becomes abnormal, making early detection clinically important.
• Thyroglobulin Antibodies (Anti-Tg): A second autoimmune marker that, when elevated alongside or independently of TPO antibodies, confirms autoimmune thyroid disease. Some women with Hashimoto’s have elevated Tg antibodies but normal TPO.

Saliva — 4-Point Cortisol Profile

• Morning Cortisol: Evaluates the Cortisol Awakening Response — the critical morning surge that sets energy, mood, and thyroid hormone activity for the day. In women, morning cortisol directly influences progesterone balance and cycle regularity.
• Noon Cortisol: Assesses mid-day stress load. Elevated noon cortisol in women impairs T4-to-T3 conversion and promotes blood sugar instability and anxiety.
• Evening Cortisol: Should be declining by early evening to allow thyroid hormone activity, melatonin production, and hormonal restoration to proceed during sleep.
• Night Cortisol: Elevated night cortisol is a primary driver of insomnia and disrupted sleep in women — and suppresses the overnight cellular thyroid hormone uptake essential for morning energy and metabolic function.

Who Should Consider This Test?

This test is particularly relevant for women who experience:

• Persistent fatigue or exhaustion that does not improve with sleep or rest
• Unexplained weight gain or difficulty losing weight despite diet and exercise
• Brain fog, poor memory, or difficulty concentrating
• Low mood, anxiety, or depression
• Feeling cold all the time, or temperature sensitivity
• Dry skin, hair thinning or loss, or brittle nails
• Irregular, heavy, or absent periods
• Fertility difficulties or recurrent miscarriage
• Perimenopausal or menopausal symptoms that are difficult to manage
• Insomnia, night waking, or unrefreshing sleep
• Chronic stress, burnout, or adrenal fatigue
• Palpitations, anxiety, or feeling wired but tired
• Previously diagnosed thyroid condition being monitored
• Family history of thyroid disease or autoimmune conditions
• Currently on HRT or the contraceptive pill (which can affect thyroid binding)

Key Features

• 10-marker thyroid and cortisol panel in a single at-home kit
• Blood spot collection for thyroid markers — finger-prick, no venepuncture
• Saliva collection for cortisol — non-invasive, captures bioavailable (active) cortisol at four time points
• Results within 3–5 working days after lab receipt
• Expert analysis by a Hormone Specialist PhD Doctor
• Clear graphical and numerical results with personalised commentary
• All-inclusive price — laboratory fees included, no hidden costs
• Valid for 12 months from purchase

How It Works

1. Order the kit online — delivered directly to your door.
2. Collect your blood spot sample via a simple finger-prick onto the collection card, and your saliva samples at four time points across the day, following the detailed instructions provided.
3. Post your samples to the lab using the pre-addressed return instructions included in your kit.
4. Receive your results within 3–5 working days, with specialist commentary and clear next-step guidance.

What Your Report Includes

• All 10 marker results with sex- and age-appropriate reference ranges
• Visual charts for your cortisol daily curve and thyroid panel values
• Clinical interpretation of the relationship between your thyroid and cortisol results
• Specialist commentary by a Hormone Specialist PhD Doctor
• Personalised next-step recommendations

Frequently Asked Questions

What does this test measure?

TSH, Free T3, Free T4, Total T4, TPO Antibodies, Thyroglobulin Antibodies (blood spot) plus Morning, Noon, Evening, and Night Cortisol (saliva) — 10 markers in total.

Why test thyroid and cortisol together?

Chronic cortisol elevation directly suppresses T4-to-T3 conversion, producing hypothyroid symptoms with a normal TSH. Testing both together allows accurate differentiation between true thyroid disease, cortisol-driven thyroid suppression, and autoimmune thyroid conditions — which require different approaches to management.

Can I use this test if I am on levothyroxine, HRT, or the contraceptive pill?

Yes. These medications can affect thyroid hormone binding and metabolism, which is precisely why testing FT3, FT4, and antibodies alongside TSH provides a more complete picture. Follow the timing guidance in your kit.

How accurate is the test?

Blood spot samples are analysed using advanced immunoassay technology; saliva cortisol is measured using LC-MS/MS — the gold standard for bioavailable hormone measurement.

When will I get my results?

Within 3–5 working days after your samples reach the laboratory.

Are there hidden costs?

No. Laboratory analysis and specialist review are fully included. You are responsible for postage to the lab.

How long is the kit valid?

12 months from purchase.

Why We Partner with ZRT Laboratory

At Hormone Lab UK, every home test kit is analysed by ZRT Laboratory, a globally recognised, CLIA-certified diagnostic and research laboratory specialising in hormone testing, thyroid testing, fertility testing, adrenal function, neurotransmitter analysis, cardiometabolic health, heavy metals, and wellness testing. Founded in 1998 by renowned biochemist and breast cancer researcher Dr. David Zava, PhD, ZRT has become one of the world’s leading laboratories for advanced functional health testing.

With more than 11 million laboratory tests performed and healthcare professionals in over 96 countries relying on its expertise, ZRT is recognised for scientific excellence, analytical accuracy, and continuous innovation. The laboratory pioneered at-home saliva hormone testing, introduced the first commercially available dried blood spot (DBS) hormone tests, and developed Dried Urine Testing (DUTS), helping make advanced laboratory diagnostics more accessible and clinically meaningful.

Every sample is analysed using state-of-the-art LC-MS/MS and ICP-MS technology under rigorous quality control standards. ZRT collaborates with the CDC, NIH, and leading universities, supporting ongoing research and advances in laboratory medicine.