Levothyroxine (INN, USAN) or L-thyroxine is a synthetic thyroid hormone that is chemically identical to thyroxine (T4), which is naturally secreted by the follicular cells of the thyroid gland. It is used to treat thyroid hormone deficiency, and occasionally to prevent the recurrence of thyroid cancer. Like its naturally secreted counterpart, levothyroxine is a chiral compound in the L-form. The related drug dextrothyroxine (D-thyroxine) was used in the past as a treatment for hypercholesterolemia (elevated cholesterol levels) but was withdrawn due to cardiac side effects. It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system. Levothyroxine sodium T4 Levothyroxine (INN, USAN) or L-thyroxine is a synthetic thyroid hormone that is chemically identical to thyroxine (T4), which is naturally secreted by the follicular cells of the thyroid gland. It is used to treat thyroid hormone deficiency, and occasionally
to prevent the recurrence of thyroid cancer. Like its naturally secreted counterpart, levothyroxine is a chiral compound in the L-form. The related drug dextrothyroxine (D-thyroxine) was used in the past as a treatment for hypercholesterolemia (elevatedcholesterol levels) but was withdrawn due to cardiac side effects. Levothyroxine sodium T4 Levothyroxine sodium T4 Levothyroxine is typically used to treat hypothyroidism, and is the treatment of choice for patients with hypothyroidism, who often require lifelong thyroid hormone therapy. It may also be used to treat goiter via its ability to lower thyroid-stimulating hormone (TSH), a hormone that is considered goiter-inducing. Levothyroxine is also used as interventional therapy in patients with nodular thyroid disease or thyroid cancer to suppress thyroid-stimulating hormone (TSH) secretion.

1. One of the thyroid hormones involved in the maintenance of metabolic homeostasis. Synthesized and stored as amino acid residues of thyroglobulin, the major protein component of the thyroid follicular colloid. Synthesis and secretion are regulated .
2. T4 is PRO-hormone, which your body converts into T3 at necessary rate only and thus it could be considered as much milder and safer drug than T3.

1. Levothyroxine sodium is an excellent fat burner since your metabolism is greatly increased while being on it. You can afford to be a little sloppier on pre-contest dieting since it will still burn fat when you are taking in a lot of calories since your metabolism is going haywire.
2. Levothyroxine is widely used by bodybuilders and fitness addicts on pre-competition cycle in order to get relief, also used by overweighed people to reduce weight. It increases metabolism and produces general stimulating effects. However, this substance should be used wisely.

Test Items	Specification	Test Results
Appearance	White or off-white powder	white powder
Identification	UV conform	Conforms
Organic nitrogenous	Conforms	Conforms
Citrate	Conforms	Conforms
Water	Not more than 1.0%	0.38%
Heavy water	Not more than 0.002%	Conforms
Related impuries	Related compound A:Not more than 2.0%	0.86%
	Individual:Not more than 0.5%	0.38%
(Z)isomer	Conforms	Conforms
Organicvolatile impuritise	Conforms	Conforms
Assay	Between98.0~102.0%	99.2%
Conclusion	This batch is complies with USP 32.