Synthroid is used to treat thyroid conditions, and replaces a hormone produced by the thyroid. This drug can be used to treat hypothyroidism or to prevent goiter caused by hormone imbalances, cancer, or radiation treatment.

Always follow your doctor’s instructions and use Synthroid exactly as prescribed.

• Take on an empty stomach, at least 30 minutes before your first meal.
• Synthroid may take several weeks to show symptom relief, and should not be discontinued unless advised by your doctor.

Synthroid is not a weight loss drug or obesity treatment. Taking it alongside appetite suppressants or weight loss drugs may be dangerous.

Before taking Synthroid, inform your doctor if you have any of the following:

• Thyrotoxicosis
• Heart attack symptoms
• Adrenal gland disorders
• Diabetes
• Heart or kidney disease
• Osteoporosis
• Allergies

Low thyroid levels can be dangerous during pregnancy, but your doctor may need to change your dose if you become pregnant.

Some dietary supplements and medications interfere with Synthroid. Take other medications 4 hours before or after Synthroid.

Common side effects of Synthroid include:

• Headache
• Muscle weakness
• Leg cramps
• Diarrhea
• Skin rash or hair loss
• Tremors and nervousness

More serious side effects include:

• Chest pain, shortness of breath, irregular heart rate
• Hair loss, dry skin and hair
• Fever or sweating
• Irritability
• Vomiting, diarrhea, appetite changes
• Changes in menstrual period

Can I take other drugs at the same time as Synthroid?

Iron supplements (including multivitamins with iron), calcium supplements and antacids can all interfere with Synthroid. Take these 4 hours before or after Synthroid, and check with your doctor about any other medication you take.

If I get pregnant, should I stop taking Synthroid?

Hypothyroidism can lead to complications during pregnancy, including miscarriage, low birth weight, and stillbirth. Don’t stop taking Synthroid if you get pregnant, and talk to your doctor about your Synthroid dose.