Levothyroxine is used to treat hypothyroidism (low thyroid hormone). Levothyroxine is given when your thyroid does not produce enough of this hormone on its own.

Levothyroxine is also used to treat or prevent goiter (enlarged thyroid gland), which can be caused by hormone imbalances, radiation treatment, surgery, or cancer.

There are many brands and forms of levothyroxine available. Not all brands are listed on this leaflet.

Levothyroxine may also be used for purposes not listed in this medication guide.

Levothyroxine should not be used to treat obesity or weight problems. Dangerous side effects or death can occur from the misuse of levothyroxine, especially if you are taking any other weight-loss medications or appetite suppressants.

If you become pregnant while using levothyroxine, do not stop using the medicine without your doctor's advice. Having low thyroid hormone levels during pregnancy could harm both mother and baby. Your dose needs may be different during pregnancy.

Tell your doctor if you are breastfeeding. Your dose needs may be different while you are nursing.

Do not give this medicine to a child without medical advice. is not approved for use by anyone younger than 6 years old. Tirosint

Since thyroid hormone occurs naturally in the body, almost anyone can use levothyroxine. However, Tell your doctor if you have: you may not be able to use this medicine if you have certain medical conditions.

Tell your doctor if you have ever had:

Tell your doctor if you have recently received radiation therapy with iodine (such as I-131).

• an untreated or uncontrolled adrenal gland disorder;
• a thyroid disorder called thyrotoxicosis; or
• symptoms of a heart attack (chest pain or heavy feeling, pain spreading to the jaw or shoulder, nausea, sweating, general ill feeling).

• a thyroid nodule;
• heart disease, a blood clot, or a blood-clotting disorder;
• diabetes (insulin or oral diabetes medication doses may need to be changed when you start using levothyroxine);
• kidney disease;
• anemia (lack of red blood cells);
• osteoporosis, or low bone mineral density;
• problems with your pituitary gland; or
• any food or drug allergies.

Use Unithroid (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have : hives; difficult breathing; swelling of your face, lips, tongue, or throat. signs of an allergic reaction

Call your doctor at once if you have:

Certain side effects may be more likely in older adults.

• fast or irregular heartbeats;
• chest pain, pain spreading to your jaw or shoulder;
• shortness of breath;
• fever, hot flashes, sweating;
• tremors, or if you feel unusually cold;
• weakness, tiredness, sleep problems (insomnia);
• memory problems, feeling depressed or irritable;
• headache, leg cramps, muscle aches;
• feeling nervous or irritable;
• dryness of your skin or hair, hair loss;
• irregular menstrual periods; or
• vomiting, diarrhea, appetite changes, weight changes.

• chest pain, irregular heartbeats;
• shortness of breath;
• headache, leg cramps, muscle pain or weakness;
• tremors, feeling nervous or irritable, trouble sleeping;
• increased appetite;
• feeling hot;
• weight loss;
• changes in your menstrual periods;
• diarrhea; or
• skin rash, partial hair loss.

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Avoid the following food products, which can make your body absorb less levothyroxine: grapefruit juice, infant soy formula, soybean flour, cotton seed meal, walnuts, and high-fiber foods.