What Is Levothyroxine Used For?
Levothyroxine is used for treating adults, children, and infants who have certain thyroid problems, such as an underactive thyroid, some types of thyroid cancer, and thyroid nodules and goiters. However, healthcare providers may occasionally recommend levothyroxine off-label to treat conditions other than thyroid problems. Treating depression is an off-label levothyroxine use (when used in conjunction with antidepressants).
Levothyroxine sodium is approved for treating the following conditions:
- An underactive thyroid (technically known as hypothyroidism)
- Some types of thyroid cancer (when used along with surgery or other treatments)
- Thyroid nodules and goiters.
The thyroid is an important gland that produces hormones that help control metabolism and other functions of the body. It is located in the neck and is one of the largest glands in the human body.
Hypothyroidism (an underactive thyroid) is a common disorder of the thyroid gland. It can occur as the result of two very different problems. It can occur due to problems that cause the thyroid to be underactive (such as an inflammation of the thyroid), or it can be caused by medical treatments for other thyroid problems, such as an overactive thyroid (hyperthyroidism).
Part of the thyroid is often intentionally destroyed (using surgery or other treatments) in an effort to treat hyperthyroidism, cancer, or nodules. However, sometimes too much of the thyroid is destroyed, leaving people with an underactive thyroid (which will need to be treated with thyroid hormone replacement, such as levothyroxine).
Whatever the cause, the end result is the same -- the thyroid does not produce enough thyroid hormones, which can result in the following symptoms of hypothyroidism:
- Weight gain
- Fatigue and weakness
- Feeling cold all the time
- Hair loss and/or coarse, dry hair
- Skin that is dry, rough, and pale
- A decreased sex drive
- Muscle cramps
- Changes in the menstrual cycle
- Memory loss.
As you can see, many of these symptoms can be subtle, and many people blame their symptoms on aging or stress, without realizing they have a thyroid problem. Because the symptoms are subtle and because hypothyroidism can be detected with a simple and inexpensive blood test, healthcare providers recommend that most adults be tested periodically.
Levothyroxine works to boost the body's thyroid hormone levels, which can work wonders for the symptoms of hypothyroidism. However, do not expect results overnight; it often takes several weeks to notice any improvement. Levothyroxine should never be used to increase energy or cause weight loss in people without a thyroid problem.
It is important to understand that with levothyroxine, more is not necessarily better. Taking too much (or taking it without a medical reason) will cause symptoms of hyperthyroidism, some of which can be quite dangerous. This is why your healthcare provider will carefully monitor you, using blood tests, to make sure you are not taking too much or too little levothyroxine.