T4 (Thyroxine)
Think of thyroxine as being like the ‘Goldilocks’ hormone. You will have problems if you have too much (hyperthyroidism) or too little (hypothyroidisim) -Mike Thompson and Becky Ting
HWN Suggests
The metabolic rate hormone that prevents 'a pain in the neck'!
Thyroxine is a hormone made in the thyroid gland that controls this metabolic rate, i.e. it keeps the body functioning at the right speed. Its full name is tetraiodothyronine with the molecular formula C15H11NO4I4. It contains 4 iodine atoms - which is why biochemists often abbreviate it to 'T4' (so as to differentiate it from other similar molecules with fewer iodines).
Articles of Interest
Free Thyroxine (FT4)
Thyroxine (T4) is the main hormone produced by the thyroid gland. About 80% of the hormone produced by the thyroid gland is T4. T4 is then converted to the more potent thyroid hormone triiodothyronine (T3) by the liver, kidney and other cells in the body. T4 and T3 together regulate the basal metabolic rate in our body, body temperature, heart rate as well as mood and sleep. However, almost all the T4 released into the bloodstream is bound to proteins such as albumin and thereby remains inactive. Only a very small proportion of unbound free T4 (FT4) is biologically active.
T4 (Thyroxine), Total and Free, Serum
Thyroxine (T4) is synthesized in the thyroid gland. T4 is metabolized to triiodothyronine (T3) peripherally by deiodination. T4 is considered a reservoir or prohormone for T3, the biologically most active thyroid hormone. About 0.05% of circulating T4 is in the free, ie, unbound, portion. The remainder is bound to thyroxine-binding globulin), prealbumin, and albumin.
Thyroxine T4
T3 and T4 are both hormones produced by the thyroid gland. T3 is the active form, while T4 is inactive.
Resources
Synthroid
Hypothyroidism is a condition requiring lifelong treatment for most people. And even though it usually requires just one pill a day to keep your thyroid hormones in balance, you still might have a hard time accepting the fact that you'll be taking your medicine for a lifetime. This is normal, especially if you've never had to take daily medication for a condition before.
You and Your Hormones
T4; tetraiodothyronine; thyroxin. The manufactured form used for thyroid hormone replacement is called L-thyroxine or Levothyroxine.
