T-3, REVERSE, LC/MS/MS (RT3 BY LC/MS/MS)

RT3; rT3; Reverse Triiodothyronine; Reverse T3

T3 Reverse, LC/MS/MS - 3,3`,5`-Triiodothyronine (reverse T3, rT3) is, along with 3,3,5`-Triiodothyronine (T3) a deiodinated metabolite of thyroxine (T4), the major secretory product of the thyroid gland and is secreted into the bloodstream. 

RT3 can be measured by a blood test. A level below 250 pg/ml (10 to 24 ng/dL) is considered normal.

The Reverse T3 (RT3) test measures the inactive form of the hormone T3 or Triiodothyronine.

Triiodothyronine is one of two major hormones produced by the thyroid (the other is T4, or thyroxine). Under normal conditions, the body converts T4 to T3 and RT3 in specific ratios. In certain circumstances, the amount converted to RT3 rises, such as when the body is under stress, as in cases of serious or acute illness or injury.