Test ID: SB-640 | Sample Type: Saliva + Dried Blood Spot | Technology: LC-MS/MS | Results Time: 3–5 Working Days After Laboratory Receives Sample | Laboratory: ZRT Laboratory – CLIA Certified | Hormone Specialist Doctor Interpretation: Included | Suitable For: Adults and Children | Collect Sample At Home: No Clinic Visit Required
What Does This Test Measure?
Saliva — 4-Point Cortisol Profile: Morning, Noon, Evening, and Night Cortisol.
Blood Spot — Full Thyroid Panel: TSH, Free T3, Free T4, Total T4, TPO Antibodies, Thyroglobulin Antibodies.
10 markers total — a clinically complete assessment of thyroid function including autoimmune markers and the full daily cortisol rhythm in a single at-home kit.
Related Symptoms
Persistent fatigue, unexplained weight gain, brain fog, low mood, cold intolerance, hair thinning, low libido, poor exercise recovery, chronic stress, burnout, insomnia, night waking, or symptoms of low testosterone with inconclusive blood results.
Who Should Consider This Test?
- Persistent fatigue that does not improve with rest or sleep
- Unexplained weight gain or difficulty losing body fat
- Brain fog, poor concentration, or low mood
- Feeling cold, hair thinning, dry skin, or slow metabolism
- Insomnia, night waking, or unrefreshing sleep
- Chronic stress or burnout
- Low libido or poor exercise recovery without full sex hormone assessment
- Diagnosed or suspected Hashimoto's thyroiditis or autoimmune thyroid disease
- On levothyroxine and wanting complete thyroid monitoring alongside cortisol
- Normal thyroid blood test results that do not match symptoms
- Men wanting a focused thyroid and cortisol assessment without a full sex hormone or cardiometabolic panel
- Family history of thyroid disease or autoimmune conditions
Why This Test Is Particularly Important for Men
- TSH alone misses cortisol-driven T3 suppression — the most commonly missed thyroid pattern in men under chronic occupational or psychological stress, producing full hypothyroid symptoms with a normal result
- Both TPO and Tg antibodies are required for complete Hashimoto's screening — some men have elevated Tg antibodies with normal TPO, making both essential
- The 4-point cortisol profile identifies which phase of the day is driving thyroid T3 suppression — morning, noon, evening, or night — and reveals night cortisol's role in worsening Hashimoto's autoimmunity
- Cortisol-driven thyroid suppression impairs Leydig cell testosterone production, compounds fatigue, and worsens metabolic function — all with a normal TSH
- Low thyroid function raises cardiovascular risk and directly suppresses testosterone synthesis — patterns invisible to TSH-only testing
Not Sure Which Test Is Right for You?
Email us at info@hormonelab.co.uk with your gender, age, symptoms, medications, and any current treatments. We will forward your enquiry to our doctors and respond within 24 hours.
How It Works
- Order your kit — delivered directly to your door
- Collect saliva at four time points (morning before 9am, noon, evening, night) and blood spot via finger-prick
- Post your samples to ZRT Laboratory using the return instructions provided
- Receive your full report by email within 3–5 working days
What You Receive
- All 10 marker results with male-specific reference ranges
- Visual cortisol rhythm chart showing your full four-point daily curve
- Visual charts for the full thyroid panel including TPO and Tg antibodies
- Integrated clinical interpretation of how cortisol rhythm and thyroid function interact by a Hormone Specialist PhD Doctor
- Personalised next-step recommendations
- Laboratory fee included — no hidden charges
Why We Use ZRT Laboratory
All testing is performed by ZRT Laboratory — a globally recognised, CLIA-certified diagnostic laboratory founded in 1998 by Dr. David Zava, PhD. ZRT has performed over 11 million tests and is trusted by healthcare professionals in 96+ countries.
- Pioneers of at-home dried blood spot (DBS) and saliva hormone testing
- Advanced LC-MS/MS technology for clinical-grade accuracy
- Qualified for the CDC Hormone Standardization (HoSt) Program
- Personalised reference ranges based on age and sex
Through our partnership with ZRT Laboratory, Hormone Lab UK delivers internationally recognised, research-backed hormone testing to people across the UK and Europe — from the comfort of home.
Frequently Asked Questions
Why test thyroid and cortisol together?
Cortisol suppresses T4-to-T3 conversion, producing hypothyroid symptoms with a normal TSH. Hashimoto's autoimmunity is directly worsened by cortisol dysregulation, particularly elevated night cortisol. Testing both together identifies whether symptoms stem from thyroid disease, cortisol-driven suppression, Hashimoto's, or a combination — each requiring a different approach.
Does this test include sex hormones or cardiometabolic markers?
No. This profile focuses on thyroid function and the 4-point cortisol rhythm. For cardiometabolic markers alongside thyroid, see the Male CardioMetabolic & Thyroid Test Kit (SB-642). For sex hormones and SHBG, see the Male Comprehensive Hormone, Thyroid & CardioMetabolic Profile (SB-646M).
Can I use this test if I am on TRT or levothyroxine?
Yes. This test helps men on TRT understand whether cortisol dysregulation or thyroid suppression is limiting therapy effectiveness. Levothyroxine dosing is most accurate when FT3, FT4, and antibodies are assessed alongside the cortisol that impairs T3 conversion.
Why is morning saliva collected before 9am?
Morning cortisol must be collected before 9am, ideally within 30 minutes of waking, to accurately capture the Cortisol Awakening Response — the key diagnostic window for adrenal and thyroid activation.
Does the price include the laboratory fee?
Yes. The full laboratory analysis fee is included. There are no additional charges. You are only responsible for posting your samples to the laboratory.
How long is the kit valid for?
The kit must be used within 12 months of the purchase date.
