Why Is Levothyroxine, Generic Synthroid Prescribed?

Your physician may prescribe levothyroxine to treat underactive thyroid if the cause of your condition is caused by irregular levels of Thyroid Stimulating Hormone (TSH) or you don’t have enough available (free) thyroxine (T4) in your blood.

It is not indicated for temporary or transient hypothyroidism.

Levothyroxine is also prescribed for suppressive therapy to treat or prevent goiter, enlarged thyroid.

What Is Hypothyroidism?

Hypothyroidism is a condition in which the thyroid does not produce enough of the major hormones T4 and triiodothyronine (T3).

What Do T4 And T3 Do?

T4 is necessary for the creation of T3. T3 is used by the cells for

• Food metabolism
• Energy creation
• Healthy skin
• Muscle development, and more.

What Are Symptoms Of Underactive Thyroid?

• Fatigue
• Depression
• Dry skin
• Slow heart beat
• Muscle aches
• Constipation
• Unexplained weight gain, and more

What Is T4?

T4 is a precursor hormone to T3. Although the thyroid produces about 80% T4 and only about 20% T3, most of the T4 in the body is bound to proteins and therefore unusable.

The pituitary gland creates TSH to regulate the amount of T4 produced by the thyroid.

What Is Free T4?

T4 that is bioactive (able to be synthesized by body tissues) is called free T4, or unbound T4.

T3 produced by the thyroid is already in a form that can be used by the body but it can also become bound to proteins and not bioactive.

What Causes Slow Thyroid?

The most common cause of hypothyroidism is Hashimoto’s thyroiditis. It is an autoimmune disease that causes the immune system to attack the thyroid gland and inhibit its production of T4 and T3.

Is Hypothyroidism More Common In Women Than Men?

Yes, women are more likely to have an underactive thyroid than men.¹ In fact, women are more likely than men to have any type of thyroid dysfunction.²

It is estimated that 20 million American have thyroid disorders and less than half are aware of their condition.³

People over the age of 60 are at higher risk for hypothyroidism and hyperthyroidism.^1,2

What Is Goiter?

Goiter is an enlargement of the thyroid hormone. It may be caused by hypothyroidism, hyperthyroidism or lack of iodine in the diet. An enlarged thyroid may not impact the gland’s function but may be uncomfortable or make it difficult to swallow. Goiters may be benign or cancerous.

References

¹ Hypothyroidism | Hashimoto’s Disease | MedlinePlus. Medlineplus.gov. https://medlineplus.gov/hypothyroidism.html. Published 2020. Accessed July 20, 2020.

² Hyperthyroidism |MedlinePlus. Medlineplus.gov. https://medlineplus.gov/hyperthyroidism.html Published 2020. Accessed July 22, 2020.

³ https://www.Thyroid.Org/Media-Main/Press-Room/; 2020 Accessed July 22, 2020.