L-Thyroxine sodium salt pentahydrate, also known as Levothyroxine, is a synthetic hormone utilized in the study of hypothyroidism. It is biologically activated into Triiodothyronine (T3) from its original form, L-Thyroxine (T4), through conversion by DIO enzymes.

Levothyroxine sodium is a useful organic compound for research related to life sciences. The catalog number is T66546 and the CAS number is 25416-65-3.

D-Thyroxine (Dextroxin) could lower cholesterol and also increases hepatic lipase which in turn improves utilization of triglycerides, leading to improve apolipoprotein E cholesterol particles.

L-Thyroxine-13C9,15N is intended for use as an internal standard for the quantification of L-thyroxine by GC- or LC-MS. L-Thyroxine is a synthetic form of the thyroid hormone thyroxine. In vivo, L-thyroxine (0.9 and 2.7 μg) inhibits synthesis and release of thyrotropin induced by thyrotropin-releasing hormone from the anterior pituitary in mice. It also reverses decreases in levels of circulating thymic serum factor (FTS) and the number of T rosette-forming cells in an old age-induced mouse model of hypothyroidism. Formulations containing L-thyroxine have been used in the treatment of hypothyroidism.

L-Thyroxine (NSC 36397) is the major hormone derived from the thyroid gland. L-Thyroxine (NSC 36397) is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. L-Thyroxine (NSC 36397) is released from thyroglobulin by proteolysis and secreted into the blood. L-Thyroxine (NSC 36397) is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.

L-Thyroxine sodium (LT4 sodium), the major hormone derived from the thyroid gland, is the agonist of Thyroid hormone receptor alpha and beta.