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Ultimate Thyroid Function Blood Test - monitor your thyroid function.

Type

Blood Testing

Biomarkers

11

Duration

30 min

Results

48 hours

Comprehensive thyroid function blood test analyzing three thyroid hormones, antibodies, and micronutrients.

This test measures three key thyroid hormones (Free T3, Free T4, and TSH) to assess thyroid function and detect potential problems early, even before symptoms appear. It also checks for antibodies (TgAb and TPO Ab) linked to autoimmune thyroid diseases, indicating future risk. Finally, it analyzes micronutrients (Vitamin B12, folate, ferritin, and Vitamin D) crucial for thyroid health, as deficiencies can mimic thyroid issues. The inflammation marker C-Reactive Protein provides an overall inflammation indicator.

Key Details

Biomarkers
2–7 thyroid markers
Fasting Required
No
Sample Type
Blood draw
Turnaround
24–48 hours
Common Use
Thyroid function, autoimmune screening

Who Is This For?

Anyone experiencing unexplained fatigue, weight changes, hair loss, cold sensitivity, or mood disturbances. People with a family history of thyroid disease or autoimmune conditions. Women planning pregnancy, as thyroid function is critical for fetal brain development. Anyone who has had a 'normal' TSH result but still suspects thyroid dysfunction.

What's Included

Thyroid-stimulating hormone (TSH)
Free Thyroxine (FT4)
Free Triiodothyronine (FT3) — if comprehensive panel
Thyroid antibodies (TPOAb, TGAb) — if autoimmune panel

Preparation Required

No fasting required for a standalone thyroid panel. If you take thyroid medication (levothyroxine/Synthroid), take your dose after the blood draw, not before — taking it beforehand can temporarily spike T4 levels and skew results. Morning testing is recommended for the most consistent TSH readings, as TSH follows a circadian rhythm and peaks overnight.

Biomarkers Tested

11
Thyroglobulin Antibodies (TGAb) IU/mL

Antibodies against thyroglobulin, a protein used by the thyroid to produce hormones. Elevated TGAb, along with TPO antibodies, confirms autoimmune thyroid disease. Also monitored after thyroid cancer treatment.

Thyroid Peroxidase Antibodies (TPO) IU/mL

Antibodies against thyroid peroxidase, an enzyme essential for thyroid hormone production. Positive TPO antibodies indicate autoimmune thyroid disease, most commonly Hashimoto's thyroiditis, even before symptoms or TSH changes appear.

Free T4 (Thyroxine) ng/dL

The unbound, active form of the main thyroid hormone T4. Free T4 directly reflects thyroid gland output and is used alongside TSH to diagnose and monitor thyroid disorders.

Free T3 (Triiodothyronine) pg/mL

The active form of thyroid hormone responsible for regulating metabolism, energy, and body temperature. Free T3 is converted from T4 in tissues and is three to four times more potent than T4.

TSH (Thyroid-Stimulating Hormone) mIU/L

The primary screening test for thyroid function. TSH is produced by the pituitary gland to regulate thyroid hormone production. High TSH indicates an underactive thyroid (hypothyroidism), while low TSH suggests an overactive thyroid (hyperthyroidism).

Vitamin B12 pg/mL

Essential for nerve function, DNA synthesis, and red blood cell formation. B12 deficiency can cause anemia, neuropathy, fatigue, and cognitive impairment. Common in vegans, vegetarians, older adults, and those taking metformin or acid-reducing medications.

Folate (Vitamin B9) ng/mL

Essential for DNA synthesis, cell division, and red blood cell formation. Folate deficiency causes megaloblastic anemia and, during pregnancy, increases the risk of neural tube defects. Works closely with vitamin B12.

Ferritin ng/mL

The primary iron storage protein. Ferritin reflects total body iron stores and is the first marker to drop in iron deficiency. However, ferritin also rises with inflammation, infection, and liver disease, which can mask true iron deficiency.

Vitamin D (25-OHD) ng/mL

The best indicator of overall vitamin D status. Vitamin D is essential for calcium absorption, bone health, immune function, and mood regulation. Deficiency is extremely common, especially in northern latitudes, and linked to increased disease risk.

hs-CRP (High-Sensitivity C-Reactive Protein) mg/L

A highly sensitive test for low-grade chronic inflammation linked to cardiovascular disease risk. Lower hs-CRP values are associated with better cardiovascular outcomes.

C-Reactive Protein (CRP) mg/L

A protein produced by the liver in response to inflammation. CRP rises rapidly during infection, injury, or inflammatory conditions. It's a general marker — elevated CRP signals inflammation but doesn't pinpoint the source.

Available at 29 locations

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Price
£68.00 £85.00

Subscription plans offer discounts up to 20% off

Category
Diagnostic
Sample Type
Blood draw
Duration
30 min
Results
48 hours
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