Levothyroxine is a synthetic form of thyroxine, a hormone produced by the thyroid gland. Doctors prescribe levothyroxine when the thyroid does not produce sufficient levels of thyroxine, a condition known as hypothyroidism. Although levothyroxine can cause weight loss as a side effect, this medicine is not intended as part of a weight-loss program, and it can be dangerous for people who do not have hypothyroidism.
Function
The thyroid gland normally produces and releases the hormones thyroxine and tri-iodothyronine, which are responsible for maintaining a normal metabolism rate. The body converts thyroxine to tri-iodothyronine, so when the thyroid gland becomes unable to produce normal amounts of thyroxine, the levels of both these hormones decrease. This causes a reduced metabolism rate, resulting in symptoms such as weight gain, dry skin, fatigue and increased sensitivity to cold. Levothyroxine replaces thyroxine and resolves this condition. The medication is available in generic form and in a variety of brand names, such as Synthroid and Thyrox.
Monitoring
Because the thyroid gland usually does not regain its ability to produce thyroxine, a person taking replacement hormones typically must do so for the rest of his life, according to Net Doctor. The patient needs regular blood tests to monitor his levels of thyroid hormones so the doctor can make dosage adjustments when necessary. High levels of thyroid hormones can cause serious negative effects, which is why people who do not have low thyroxine should not take levothyroxine for weight loss or any other purposes.
Side Effects
Levothyroxine primarily causes side effects when it leads to high levels of thyroxine in the body. One of these effects is weight loss. Other possible side effects include diarrhea, vomiting, headaches, menstrual irregularities, muscle cramps or weakness, tremors, restlessness, insomnia, flushing, sweating, fever and increased sensitivity to heat.
Warning
All levothyroxine medications have a black box warning on the packaging. This warning from the U.S. Food and Drug Administration tells consumers to never use thyroid hormone medicine for weight loss. In people with normal thyroid function, taking thyroxine is ineffective for weight loss and can cause dangerous toxicity levels, according to PubMed Health. The situation worsens if the person also takes stimulant drugs, which are commonly used as an appetite suppressant. High levels of thyroxine in the body can cause psychotic reactions, heart palpitations, angina, a fast heart rate, an irregular heartbeat, congestive heart failure, seizures and shock.
Member Comments