Test ID: S-122 | Sample Type: Saliva | 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
What Does This Test Measure?
Saliva — Cortisol Awakening Response + Full Adrenal Profile (LC-MS/MS): Cortisol Upon Waking, Cortisol +30 Minutes, Cortisol +60 Minutes, Midday Cortisol, Evening Cortisol, Night Cortisol, DHEAS.
7 markers — the most detailed adrenal assessment available at home, capturing the full morning CAR window, the complete daily cortisol rhythm, and the primary adrenal sex hormone precursor in a single saliva kit.
Related Symptoms
Waking exhausted despite adequate sleep, anxiety or heart palpitations on waking, persistent fatigue that does not respond to rest, insomnia or night waking, racing thoughts at bedtime, PMS that has worsened particularly in the luteal phase, irregular or heavy periods, perimenopausal or menopausal symptoms including night sweats, chronic stress or burnout, low libido, brain fog, unexplained abdominal weight gain, sugar or salt cravings, low blood pressure or dizziness on standing, or suspected adrenal fatigue or HPA axis dysfunction.
Did You Know?
The Cortisol Awakening Response is directly modulated by oestrogen and progesterone in women — meaning it shifts measurably across the menstrual cycle, worsens during perimenopause as sex hormones decline, and is profoundly disrupted by chronic stress and burnout. A blunted CAR — the most common pattern in burned-out women — is associated with profound morning exhaustion, emotional flatness, and immune suppression that persists regardless of sleep duration. An exaggerated CAR — common in women with high-demand lifestyles or trauma history — is associated with morning anxiety, heart palpitations, and acute progesterone suppression via pregnenolone steal. These two patterns cause similar symptoms but require opposite clinical approaches, and a single morning cortisol reading cannot distinguish them. The three-sample CAR window is the minimum required to make this distinction.
Who Should Consider This Test?
- Waking exhausted despite adequate sleep, unable to get going in the morning
- Anxiety, heart palpitations, or a sense of dread on waking
- Persistent fatigue that does not respond to rest or increased sleep
- Insomnia, night waking, or racing thoughts at bedtime
- PMS that has worsened — particularly mood symptoms, anxiety, or irritability in the luteal phase
- Irregular, heavy, or missed menstrual cycles
- Perimenopausal or menopausal symptoms including hot flushes, night sweats, and low mood
- Chronic stress, burnout, or emotional exhaustion
- Low libido or reduced motivation
- Brain fog, poor concentration, or memory difficulties
- Unexplained weight gain, particularly around the abdomen
- Sugar or salt cravings, especially in the afternoon
- Low blood pressure or dizziness on standing
- PCOS, thyroid conditions, or known hormonal imbalance
- Women on HRT with residual symptoms unexplained by sex hormone levels alone
- Suspected adrenal fatigue or HPA axis dysfunction
Why This Test Is Particularly Important for Women
- The CAR is directly modulated by oestrogen and progesterone — it shifts across the menstrual cycle, deteriorates during perimenopause, and is profoundly disrupted by chronic stress; disrupted CAR patterns in women are strongly linked to PMS, perimenopausal symptoms, chronic fatigue, and mood disorders, often before any other hormonal abnormality is detectable
- The three-sample CAR window (waking, +30 min, +60 min) is the only method that distinguishes a blunted from an exaggerated CAR — two opposite patterns requiring opposite clinical interventions that produce similar symptoms and are indistinguishable from a single morning reading
- Elevated evening cortisol prevents the progesterone and melatonin rise in early evening — directly driving insomnia, PMS mood symptoms in the luteal phase, and the sleep disruption that compounds hormonal exhaustion
- Elevated night cortisol is the primary driver of night sweats and insomnia in perimenopause — a pattern frequently attributed to oestrogen deficiency alone but driven or compounded by adrenal dysfunction that HRT cannot resolve
- DHEAS is the primary adrenal precursor to both oestrogen and testosterone in women — combined with the full CAR pattern, the DHEAS result provides the most complete assessment of adrenal sex hormone reserve and long-term stress burden available from a single at-home test
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.
Collection Protocol
Six saliva samples collected across the day:
- Sample 1: Within 5 minutes of waking — before getting out of bed
- Sample 2: 30 minutes after waking
- Sample 3: 60 minutes after waking
- Sample 4: Midday
- Sample 5: Evening
- Sample 6: Night (before sleep)
Full collection instructions and guidance on optimal cycle timing are included in the kit. The three morning samples must be collected at exact intervals — do not eat, drink, or brush your teeth before completing all three.
How It Works
- Order your kit — delivered directly to your door
- Collect six saliva samples across the day following the detailed instructions provided
- 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 six cortisol readings and DHEAS with female-specific reference ranges
- Full diurnal cortisol curve graph including the complete CAR window
- Written interpretation by a Hormone Specialist PhD Doctor including CAR pattern classification, cortisol–progesterone interaction, cycle and life-stage context, and DHEAS adrenal reserve evaluation
- 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
What does this test measure?
Cortisol at six time points (waking, +30 min, +60 min, midday, evening, night) and DHEAS — 7 markers providing the most detailed adrenal and HPA axis assessment available from a single at-home saliva test.
Why is the CAR particularly important for women?
The CAR is directly modulated by oestrogen and progesterone and shifts across the menstrual cycle and the menopause transition. Disrupted CAR patterns are strongly linked to PMS, perimenopause symptoms, chronic fatigue, and mood disorders in women — often before any other hormonal abnormality is detectable by standard testing.
When should I collect my samples during my menstrual cycle?
This test can be taken at any point in your cycle. Guidance on optimal timing for cycling, perimenopausal, and postmenopausal women is included in your kit.
Can I use this test if I am on HRT, the contraceptive pill, or other hormonal medication?
Yes. This test is suitable for women on HRT, the contraceptive pill, or other hormonal medications. It is particularly valuable for identifying whether adrenal dysfunction is driving residual symptoms that hormone therapy is not resolving.
Do I need to fast before collecting?
No fasting is required. Follow the timing instructions carefully — particularly for the three morning samples, which must be collected at exact intervals and before eating, drinking, or brushing your teeth.
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.
