Skip to content

T4 (thyroxine)

Home medical analysis | Medical Laboratory

T4 (thyroxine) Test


It exists under 2 forms – the free (active) form and the one bound to a protein, representing a reserve.

A hormone produced by the thyroid gland. The amount is controlled by the TSH (the thyroid-stimulating hormone) and by the amount of iodine. A role in the sugar and fat metabolism and in the bone and nervous system development.

Testing moment
No fasting needed prior to blood sampling.
Low values causes
  • Hypothyroidism (the slackened functioning of the thyroid gland)
  • Certain drugs
High values causes
  • Hyperthyroidism (the accelerated functioning of the thyroid gland)

A test to be preferably carried out in the morning. Stress and drug intake prior to sampling should be avoided. The test measures the free and total level of T4.

How to get tested

Contact us at 514 975-5226 for a blood test at home for the purpose of evaluating your t4 (thyroxine).

Perscription & Insurance

All our tests require a medical prescription recommended by any practicing doctor in the province of Quebec.

These prescriptions are necessary in order to proceed with either test and we urge that all medical requests originating from offices or clinics be duly identified.

All medical analysis requested by your doctor are reimbursed by a majority of private insurance companies!