What is Synthroid (levothyroxine) used for?

Synthroid is a prescription medication for oral use. It is used to treat hypothyroidism. This is a condition in which the body does not make enough thyroid hormone. Low thyroid hormone levels can lead to various symptoms such as excessive tiredness, lack of energy, constipation, weight gain, dry skin, hair loss, joint and muscle pain, cold sensitivity, depression, and irregular or heavy menstrual periods in women. Synthroid replaces thyroid hormone and can reverse these symptoms.

 How does Synthroid (levothyroxine) work?

Synthroid is a synthetic version of the T4 hormone made by the thyroid gland. In people with low thyroid hormone levels, Synthroid works by replacing the hormone and bringing the levels back to normal. 

What are Synthroid (levothyroxine) doses?

Synthroid is available in tablet and capsule form. Common Synthroid doses are:

Oral tablet/capsule strength:  25 mcg | 50 mcg | 75 mcg | 88 mcg | 100 mcg | 112 mcg | 137 mcg | 150 mcg | 175 mcg | 200 mcg | 300 mcg

The starting dose of Synthroid is usually the full replacement dose and is based on body weight. It is approximately 100-125 mcg per day for a 150-pound adult. Dose adjustments are made based on the response and thyroid levels on lab testing.