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Thyroxine-Free (Free T4)

Thyroxine-Free (Free T4)

£11.88
This add-on measures free thyroxine (Free T4), the active thyroid hormone that helps regulate metabolism and energy. Abnormal levels may indicate thyroid dysfunction—even without clear symptoms.
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About this test

  • atigue or persistent low energy
  • Sensitivity to cold or feeling unusually warm
  • Unexplained weight gain or loss
  • Dry skin or brittle hair
  • Hair thinning or hair loss
  • Irregular or heavy menstrual periods
  • Constipation or diarrhoea
  • Depression, anxiety, or mood swings
  • Slow heart rate or palpitation
  • Puffy face or swelling in the neck (goitre)
  • Difficulty concentrating or memory problems ("brain fog")
  • Muscle weakness or joint stiffness
  • Hoarseness or voice changes
  • No noticeable symptoms in early stages

Recommended for individuals experiencing symptoms such as fatigue, weight changes, mood fluctuations, sensitivity to cold or heat, or irregular periods. Ideal for those with a personal or family history of thyroid disorders, autoimmune conditions, or unexplained changes in metabolism. Also suitable for individuals monitoring their thyroid function, especially if taking thyroid medication, or those seeking early insights into hormonal balance as part of a proactive health check.








  • Hypothyroidism (underactive thyroid)
  • Hyperthyroidism (overactive thyroid)
  • Hashimoto’s thyroiditis (autoimmune hypothyroidism)
  • Graves’ disease (autoimmune hyperthyroidism)
  • Thyroid hormone resistance
  • Goitre or thyroid nodules
  • Post-thyroidectomy or radioiodine therapy monitoring
  • Pituitary gland disorders affecting TSH regulation
  • Medication-induced thyroid dysfunction
  • Unexplained weight gain or loss, menstrual irregularities, or infertility related to thyroid imbalance

Symptoms

  • atigue or persistent low energy
  • Sensitivity to cold or feeling unusually warm
  • Unexplained weight gain or loss
  • Dry skin or brittle hair
  • Hair thinning or hair loss
  • Irregular or heavy menstrual periods
  • Constipation or diarrhoea
  • Depression, anxiety, or mood swings
  • Slow heart rate or palpitation
  • Puffy face or swelling in the neck (goitre)
  • Difficulty concentrating or memory problems ("brain fog")
  • Muscle weakness or joint stiffness
  • Hoarseness or voice changes
  • No noticeable symptoms in early stages

Who should be test

Recommended for individuals experiencing symptoms such as fatigue, weight changes, mood fluctuations, sensitivity to cold or heat, or irregular periods. Ideal for those with a personal or family history of thyroid disorders, autoimmune conditions, or unexplained changes in metabolism. Also suitable for individuals monitoring their thyroid function, especially if taking thyroid medication, or those seeking early insights into hormonal balance as part of a proactive health check.








When to test

  • Hypothyroidism (underactive thyroid)
  • Hyperthyroidism (overactive thyroid)
  • Hashimoto’s thyroiditis (autoimmune hypothyroidism)
  • Graves’ disease (autoimmune hyperthyroidism)
  • Thyroid hormone resistance
  • Goitre or thyroid nodules
  • Post-thyroidectomy or radioiodine therapy monitoring
  • Pituitary gland disorders affecting TSH regulation
  • Medication-induced thyroid dysfunction
  • Unexplained weight gain or loss, menstrual irregularities, or infertility related to thyroid imbalance

What's measured

What gets tested