When in the menstrual cycle should the sample be collected?

Timing depends on the clinical question. Mid-follicular (day 3–5) gives baseline oestradiol and resting progesterone; mid-luteal (day 19–21 of a 28-day cycle) captures peak progesterone to confirm ovulation. Practitioners must specify the collection day and interpret results in that context.

Why is SHBG included in the panel?

SHBG binds testosterone and oestradiol, modulating their bioavailability. Measuring SHBG alongside total sex steroids allows calculation of the free androgen index and clarifies whether a borderline total testosterone reflects true androgen deficiency or excess, or simply altered binding-protein concentration.

Is a single-point cortisol measurement clinically useful?

A single dried blood spot cortisol is a snapshot and less informative than diurnal salivary cortisol or 24-hour urine free cortisol for diagnosing Cushing syndrome or adrenal insufficiency. It is used in functional practice to complement multi-point sampling or when venepuncture is not feasible, but interpretation is limited.

Does the panel require fasting?

No. Fasting is not required, though practitioners should instruct consistent timing — morning collection for cortisol and TSH, and documented menstrual day for sex steroids — to ensure interpretability and serial comparability.

Can the panel be used to monitor hormone replacement therapy?

Yes. The panel is commonly ordered to monitor bioidentical oestrogen, progesterone, testosterone, and thyroid hormone replacement. Practitioners should document the timing of the last dose relative to sample collection, as transdermal and oral formulations have different pharmacokinetics.

What should patients do if the blood spot does not fill the circle?

Each collection circle must be fully saturated in a single application. If the spot is incomplete, the laboratory may reject it and request recollection. Patients should warm their hands, allow the finger to hang down, and apply steady pressure to ensure adequate blood flow.

How long do results take?

Results are typically available 7–10 business days from receipt of the dried blood spot card at ZRT Laboratory, including LC-MS analysis and quality control for all nine analytes.

BML-THY-030thyroid endocrineUSA

Blood Spot LCMS Hormones 7 with SHBG and Thyroids

Q: Are dried blood spot hormone results equivalent to serum results?

No. Dried blood spot concentrations are method-specific and not directly interchangeable with serum immunoassay or LC-MS values because of differences in sample matrix, extraction, and calibration. Practitioners should use the laboratory's dried blood spot reference intervals and avoid cross-platform comparison.

The Blood Spot LCMS Hormones 7 with SHBG and Thyroids panel uses fingerprick dried blood spot collection and liquid chromatography–tandem mass spectrometry to quantify oestradiol, progesterone, testosterone, DHEA-S, cortisol, TSH, free T4, free T3, and SHBG in a single specimen, offering practitioners an integrated view of thyroid, gonadal, and adrenal endocrine status with at-home convenience…

Biomarkers

Dried blood spot

Sample

7–10 business days

Turnaround

Fasting

What is the Blood Spot Hormone & Thyroid Panel test?

The Blood Spot LCMS Hormones 7 with SHBG and Thyroids panel integrates dried blood spot collection with liquid chromatography–tandem mass spectrometry to quantify seven steroid and thyroid hormones alongside sex hormone-binding globulin in a single fingerprick sample. It is designed for practitioners seeking a comprehensive snapshot of reproductive, adrenal, and thyroid endocrine status without the logistical and patient-acceptance barriers of venepuncture, particularly in functional, integrative, and telemedicine settings. Dried blood spot sampling offers practical advantages — patients collect the specimen at home or in-office, the card is stable at ambient temperature during shipment, and the method bypasses many of the protein-binding and immunoassay cross-reactivity issues that complicate serum hormone testing. Because LC-MS directly measures each analyte's molecular mass, it delivers high specificity at the low concentrations typical of female and paediatric populations. Practitioners order this panel to investigate suspected hypogonadism, oestrogen or progesterone deficiency, polycystic ovary syndrome, adrenal androgen excess, thyroid dysfunction, and to monitor hormone replacement or optimisation therapy in a single integrated assay. The inclusion of SHBG and the derived free androgen index allows refined interpretation of sex-steroid bioavailability, bridging the gap between total hormone concentrations and clinical phenotype.

What does the Blood Spot Hormone & Thyroid Panel test measure?

E2(Oestradiol)

Range: Sex- and menstrual-phase-specific; dried blood spot concentrations correlate with serum free hormone and are method-specific.Optimal: Optimal ranges depend on sex, reproductive status, and clinical goal; functional practitioners may target mid-follicular values of 50–150 pg/mL in cycling women and 40–100 pg/mL in men, though these are not universally standardised.pg/mL / pmol/L

Oestradiol is the principal oestrogenic steroid, synthesised in ovarian granulosa cells, testicular Leydig cells, adipose tissue, and brain. Most circulating E2 is bound to sex hormone-binding globulin and albumin; dried blood spot sampling captures primarily the unbound, biologically active fraction, offering a surrogate for free oestradiol without the technical complexities of equilibrium dialysis.

Oestradiol drives endometrial proliferation, bone mineralisation, vascular health, and neurocognitive function. Clinicians use it to assess ovarian reserve, investigate amenorrhoea or anovulation, guide hormone replacement, and monitor aromatase-inhibitor therapy in oncology. Dried blood spot measurement is particularly suited to serial sampling in menstrual mapping and telemedicine contexts.

P4(Progesterone)

Range: Follicular phase <1 ng/mL; mid-luteal 5–20 ng/mL; method- and timing-specific.Optimal: Mid-luteal values above 10 ng/mL are widely accepted as evidence of adequate ovulation; functional targets may aim for 15–25 ng/mL, though robust outcome data for these thresholds are limited.ng/mL / nmol/L

Progesterone is secreted by the corpus luteum after ovulation, sustaining the secretory endometrium and modulating immune and central nervous system function. Blood spot collection reflects total circulating hormone with minimal protein-binding artefact, making it a convenient marker of luteal sufficiency.

Progesterone measurement confirms ovulation, assesses luteal phase adequacy in infertility and recurrent pregnancy loss, and monitors exogenous progesterone therapy. Timing is critical — practitioners order mid-luteal (day 21 of a 28-day cycle) sampling to capture peak secretion.

T(Testosterone)

Range: Adult male approximately 300–1,000 ng/dL; adult female 15–70 ng/dL; dried blood spot intervals are assay-specific and not directly equivalent to serum total testosterone.Optimal: Functional practitioners often target blood spot testosterone toward the upper half of the reference interval for symptomatic men; women's optimal ranges are narrower and highly individual.ng/dL / nmol/L

Testosterone is synthesised in testicular Leydig cells and ovarian theca cells under LH control, with peripheral conversion in adipose and skin. The majority is bound to SHBG; blood spot sampling reflects both bound and free fractions but correlates more closely with bioavailable testosterone than with serum total T measured by immunoassay.

Testosterone underpins muscle mass, libido, bone density, and erythropoiesis. Clinicians use it to investigate hypogonadism, polycystic ovary syndrome, and adrenal androgen excess, and to monitor testosterone replacement or suppression. LC-MS measurement on dried blood spot avoids immunoassay cross-reactivity, a particular advantage at the low concentrations seen in women.

DHEA-S(Dehydroepiandrosterone Sulphate)

Range: Age- and sex-specific; peaks in the third decade and declines thereafter. Blood spot reference intervals are derived from LC-MS and not interchangeable with serum immunoassay norms.Optimal: Age-adjusted mid-range values are often cited in functional medicine as optimal for vitality and immune function, though evidence linking specific dried blood spot DHEA-S concentrations to clinical outcomes remains exploratory.µg/dL / µmol/L

DHEA-S is secreted by the zona reticularis of the adrenal cortex and serves as a reservoir androgen with an elimination half-life of hours, making it stable across the day. It undergoes peripheral conversion to androstenedione, testosterone, and oestrogens, contributing to androgen-dependent physiology in both sexes.

DHEA-S is the marker of choice for adrenal androgen production, used to distinguish adrenal from gonadal androgen excess, investigate premature adrenarche, and assess adrenal reserve in suspected adrenal insufficiency. Dried blood spot sampling offers stability and convenience for population screening and longitudinal monitoring.

F(Cortisol)

Range: Morning 5–25 ng/mL; afternoon/evening lower. Single time-point dried blood spot cortisol is less informative than diurnal salivary profiles but can serve as a snapshot.Optimal: Functional practitioners interpret morning dried blood spot cortisol within the mid-range of the reference interval as reflecting balanced HPA axis tone, though this framework is not diagnostically validated.ng/mL / nmol/L

Cortisol is the principal glucocorticoid, synthesised in the adrenal zona fasciculata under ACTH drive and subject to pronounced diurnal variation with a morning peak. Blood spot cortisol represents total circulating hormone; because cortisol-binding globulin is not captured by the collection method the relationship to serum total and free cortisol is complex and method-dependent.

Cortisol assessment underpins the diagnosis of Cushing syndrome, adrenal insufficiency, and stress-related dysregulation. Single-point dried blood spot cortisol has limited diagnostic power compared to 24-hour urine free cortisol or salivary diurnal curves, but it is used in functional practice to complement multi-point sampling or when venepuncture is impractical.

TSH(Thyroid-Stimulating Hormone)

Range: Approximately 0.4–4.0 µIU/mL; intervals vary by assay and population, and dried blood spot TSH correlates well with serum but requires method-specific validation.Optimal: Many endocrinologists and functional practitioners favour TSH values between 0.5 and 2.5 µIU/mL as optimal for well-being, particularly in early pregnancy and subclinical hypothyroidism, though treatment thresholds remain debated.µIU/mL / mIU/L

TSH is a glycoprotein hormone secreted by anterior pituitary thyrotrophs in response to hypothalamic TRH and negative feedback from circulating thyroid hormones. It stimulates thyroid follicular cells to synthesise and release T4 and T3. TSH exhibits modest diurnal and pulsatile variation but remains stable enough for single time-point screening.

TSH is the first-line test for thyroid dysfunction, highly sensitive for primary hypothyroidism and hyperthyroidism because of the log-linear TSH–free T4 relationship. Dried blood spot TSH is used in newborn screening programmes worldwide and is increasingly offered in direct-access and telemedicine thyroid panels for adults.

FT4(Free Thyroxine)

Range: Approximately 0.8–1.8 ng/dL; dried blood spot free T4 is calculated or directly measured by LC-MS and may not match immunoassay-based serum results.Optimal: Optimal free T4 is often cited as mid-to-upper reference range for symptom resolution on thyroid hormone replacement, though target ranges should be individualised and are not robustly defined for dried blood spot platforms.ng/dL / pmol/L

Thyroxine is the principal secretory product of the thyroid gland, circulating predominantly bound to thyroxine-binding globulin, transthyretin, and albumin. The free fraction (0.02–0.03%) is biologically active and subject to peripheral deiodination to T3. Dried blood spot sampling bypasses protein-binding artefacts encountered in some serum free T4 assays.

Free T4 quantifies thyroid hormone availability and is essential for classifying thyroid dysfunction when TSH is abnormal — low in primary hypothyroidism, high in hyperthyroidism, and discordant in central thyroid disease or non-thyroidal illness. Practitioners order FT4 alongside TSH to guide levothyroxine dosing and investigate subclinical or secondary disorders.

FT3(Free Triiodothyronine)

Range: Approximately 2.3–4.2 pg/mL; assay- and method-specific.Optimal: Functional practitioners often target free T3 in the upper half of the reference interval for optimal energy and metabolic health, though robust clinical trial evidence supporting specific dried blood spot FT3 targets is lacking.pg/mL / pmol/L

Triiodothyronine is the most potent thyroid hormone, generated predominantly by peripheral 5'-deiodination of T4 in liver, kidney, and other tissues, with a smaller contribution from direct thyroid secretion. Free T3 exerts genomic and non-genomic effects on metabolism, thermogenesis, and cardiovascular function.

Free T3 provides insight into peripheral thyroid hormone activation and tissue thyroid status, particularly in patients on levothyroxine monotherapy who convert T4 to T3 variably. It is the key diagnostic marker in T3 thyrotoxicosis and is used to assess adequacy of combination T4/T3 therapy. Dried blood spot FT3 offers a practical alternative when repeated venepuncture is burdensome.

SHBG(Sex Hormone-Binding Globulin)

Range: Adult male 10–57 nmol/L; adult female 18–114 nmol/L; intervals are method- and population-dependent.Optimal: Optimal SHBG is context-dependent; values toward the middle of the reference range are often considered balanced, though very low SHBG (<20 nmol/L in women) warrants metabolic evaluation.nmol/L

SHBG is a hepatic glycoprotein that binds testosterone and oestradiol with high affinity, modulating their bioavailability. Its synthesis is upregulated by oestrogen and thyroid hormone and downregulated by insulin and androgens, making it a surrogate marker of metabolic and hormonal milieu.

SHBG refines the interpretation of total sex-steroid measurements — low SHBG in the setting of normal total testosterone suggests high free testosterone and is common in polycystic ovary syndrome and metabolic syndrome, while high SHBG can mask androgen deficiency. Including SHBG in a hormone panel allows calculation of the free androgen index and better assessment of bioavailable hormone.

FAI(Free Androgen Index)

Range: Male <100; female <5; calculated as (total testosterone ÷ SHBG) × 100.Optimal: Optimal FAI thresholds are not rigorously defined for dried blood spot platforms; conventional serum-based cut-offs (FAI >5 in women suggesting hyperandrogenism) are applied with caution and method-specific validation.ratio

The free androgen index is a calculated ratio that estimates bioavailable testosterone by dividing total testosterone by SHBG. It correlates reasonably well with free testosterone measured by equilibrium dialysis and is more accessible than direct free hormone assays.

FAI is used to identify hyperandrogenism in women with polycystic ovary syndrome and to assess functional androgen status in men when SHBG is abnormal. It helps practitioners decide whether a borderline total testosterone is clinically significant or merely reflects altered binding-protein concentrations.

Why is the Blood Spot Hormone & Thyroid Panel test ordered?

Investigation of menstrual irregularity, anovulation, or luteal phase deficiency, where simultaneous oestradiol, progesterone, and testosterone provide a comprehensive hormone profile
Assessment of suspected polycystic ovary syndrome with calculation of the free androgen index to quantify hyperandrogenism when SHBG is low
Evaluation of male hypogonadism or low libido, where LC-MS testosterone avoids immunoassay interference and SHBG clarifies bioavailable androgen status
Monitoring of bioidentical hormone replacement therapy in perimenopause and menopause, where serial fingerprick sampling is more acceptable than repeated venepuncture
Concurrent thyroid and sex-hormone screening in patients with fatigue, weight change, or mood disturbance, where overlapping symptoms require multi-system assessment
Adrenal androgen evaluation with DHEA-S in suspected adrenal insufficiency, premature adrenarche, or non-classic congenital adrenal hyperplasia
Telemedicine and direct-access contexts where venepuncture is impractical and a single at-home collection capturing thyroid, gonadal, and adrenal axes is operationally advantageous
Paediatric or needle-phobic populations, where fingerprick collection is better tolerated and yields clinically useful LC-MS data across the measured analytes

Sample collection and turnaround

Sample type

Dried blood spot

Fasting required

Collection method

Finger prick

Turnaround

7–10 business days

Collection notes

Patient self-collection via fingerprick; blood is applied to a filter-paper card marked with collection circles, allowed to dry at room temperature for at least 30 minutes, then sealed in a foil pouch with desiccant and returned by post. Practitioner instructions must specify timing — morning collection for cortisol and TSH consistency, mid-follicular (day 3–5) or mid-luteal (day 19–21) for sex steroids depending on clinical question. Collection kits include lancet, collection card, desiccant, and prepaid return mailer.

Specimen requirements

Each collection circle must be fully saturated with blood in a single application; layering or partial filling invalidates the spot. Avoid touching the collection area. Air-dry the card completely before sealing; damp cards promote microbial growth and analyte degradation. Ship within 24–48 hours of collection when possible, though dried spots are stable for several days at ambient temperature.

What can affect Blood Spot Hormone & Thyroid Panel results?

variableTiming within the menstrual cycle

Oestradiol and progesterone fluctuate across the cycle; practitioners must specify collection day (mid-follicular for baseline oestradiol, day 19–21 for luteal progesterone) and interpret results in that context or the data will be uninterpretable.

elevatesExogenous hormone therapy

Oral, transdermal, and intramuscular oestrogen, progesterone, testosterone, or DHEA will raise the corresponding analyte; a medication and supplement history is essential, and the panel is often used expressly to monitor such therapy.

variableDiurnal variation in cortisol

Cortisol peaks in the morning and declines through the day; single-point dried blood spot cortisol should be collected at a consistent time (typically morning) for serial comparability, and interpretation of a single value is limited without context.

variableHaematocrit and spot saturation

Inadequate blood volume, incomplete saturation of the collection card, or clotting during application can yield unreliable results; patients must be instructed to fill the marked circle completely, and laboratories reject incomplete spots.

variableAmbient temperature and humidity during collection and transit

Dried blood spots are stable at room temperature for days to weeks, but extreme heat or humidity can degrade some analytes; specimens should be dried fully before sealing and shipped promptly.

variableMedications affecting SHBG

Oral oestrogen, thyroid hormone, and anticonvulsants raise SHBG; insulin resistance, obesity, androgens, and glucocorticoids lower it, altering calculated free androgen index and the interpretation of total sex steroids.

What do Blood Spot Hormone & Thyroid Panel results mean?

Elevated

Elevated oestradiol: ovarian hyperstimulation, oestrogen therapy, or oestrogen-secreting tumour (rare). Elevated progesterone outside the luteal phase: exogenous progesterone, congenital adrenal hyperplasia, or an adrenal or ovarian tumour. Elevated testosterone in women: PCOS, non-classic CAH, androgen therapy, or androgen-secreting tumour. Elevated DHEA-S: adrenal androgen excess, adrenal hyperplasia, or DHEA supplementation. Elevated cortisol: Cushing syndrome (though single-point screening is insensitive), stress, or exogenous glucocorticoid. Elevated TSH with low FT4: primary hypothyroidism. Suppressed TSH with elevated FT4 or FT3: primary hyperthyroidism. Elevated SHBG: hyperthyroidism, oestrogen excess, or hepatic disease.

Normal

Results within the reference interval do not exclude mild endocrine dysfunction, particularly if symptoms are present or if sampling timing was suboptimal. Thyroid and sex-steroid physiology is dynamic; a single snapshot may miss intermittent or cyclical abnormalities, and serial or provocative testing may be required. Normal dried blood spot values do not replace clinical judgement or, where indicated, serum confirmatory testing.

Reduced

Low oestradiol: ovarian insufficiency, hypogonadotrophic hypogonadism, menopause, or aromatase inhibitor therapy. Low progesterone in the mid-luteal phase: anovulation, inadequate corpus luteum, or early sample timing. Low testosterone in men: primary or secondary hypogonadism; in women, adrenal insufficiency or low DHEA-S. Low DHEA-S: adrenal insufficiency, hypopituitarism, or advancing age. Low cortisol: adrenal insufficiency or sampling late in the day. Elevated TSH with normal or low FT4: subclinical or overt primary hypothyroidism. Low TSH with low FT4: central hypothyroidism or non-thyroidal illness. Low SHBG: insulin resistance, metabolic syndrome, PCOS, or androgen excess.

Note: Dried blood spot hormone concentrations are not directly interchangeable with serum immunoassay or LC-MS results because of differences in sample matrix, extraction, and calibration. Reference intervals are method- and laboratory-specific, and practitioners should not compare results across platforms or labs. Timing is critical for sex steroids — menstrual day, time of day, and relationship to exogenous hormone dosing must be documented. Single-point cortisol on a dried blood spot has limited diagnostic utility compared to diurnal salivary cortisol or 24-hour urine free cortisol. The calculated free androgen index is an estimate of bioavailable testosterone and is less precise than equilibrium dialysis free testosterone. Optimal ranges cited in functional and integrative practice often derive from expert consensus rather than randomised controlled trial evidence and should be communicated as such.

Frequently asked questions

Dried blood spot collection is performed by fingerprick at home or in-office, avoiding the need for venepuncture and a laboratory visit. The specimen is stable at room temperature during shipping, and LC-MS analysis delivers high specificity, particularly for low-concentration hormones in women and children. It is especially suited to serial monitoring and telemedicine.

How to access the Blood Spot Hormone & Thyroid Panel test

The Blood Spot Hormone & Thyroid Panel reference page is free and open to all practitioners. Create a free practitioner account to see pricing, save tests to your list, and generate requisition forms. Verification takes 1–2 business days.

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About this page

Published: October 7, 2026

Last reviewed: October 7, 2026

References:

Keevil BG, et al. Assessment and validation of liquid chromatography–tandem mass spectrometry methods for steroid analysis. Clin Biochem. (2016)
Handelsman DJ, Wartofsky L. Requirement for mass spectrometry sex steroid assays in the Journal of Clinical Endocrinology and Metabolism. J Clin Endocrinol Metab. (2013)
American Thyroid Association guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. Thyroid. (2016)
Endocrine Society clinical practice guideline on the diagnosis and treatment of primary adrenal insufficiency. J Clin Endocrinol Metab. (2016)
Teede HJ, et al. Recommendations from the international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Hum Reprod. (2018)

This content is for licensed healthcare practitioners only and does not constitute medical advice. Clinical decisions should be based on the full clinical picture and not on any single test result.