Thyroxine (T4) 50mcg

Thyroxine, commonly known as T4 and tetraiodothyronine, is the primary hormone released by your thyroid gland into your bloodstream. Your thyroid gland also produces trace amounts of triiodothyronine (T3). T4 and T3 function in tandem and are together referred to as “thyroid hormone.”

Hormones are molecules that help your body coordinate diverse tasks by transporting information through your blood to your organs, muscles, and other tissues. These signals instruct your body on what to do and when.

T4 produced by your thyroid is inactive, which means it does not affect your body’s cells. However, the majority of this thyroxine is converted by your liver and kidneys into triiodothyronine (T3), an active hormone that affects the cells in your body.

How should I get ready for a T4 (thyroxine) test?

A T4 test normally does not require any particular preparation. You may need to cease taking specific drugs or supplements, depending on the reason for the test. In any case, your doctor will give you specific advice.

Biotin, a nonprescription nutrient, can cause various thyroid tests to appear abnormal when they are not. To avoid this impact, it is advisable to discontinue biotin-containing pills 3 to 5 days before any thyroid-related blood draw.