Levothyroxine sodium (INN: Levothyroxine)

Film-coated tablets
Available forms may vary by country. Please refer to your local label.

Oral use

This medicine is used to manage various forms of hypothyroidism (underactive thyroid), including congenital and acquired types. It may also be used to help suppress thyroid-stimulating hormone (TSH) in certain thyroid conditions, such as goiter or thyroid cancer, as advised and prescribed by a healthcare professional.
Approved uses may differ by country. Always refer to the locally approved product information.

Synthroid® contains levothyroxine sodium, a synthetic form of the thyroid hormone thyroxine (T4), which is normally produced by the thyroid gland. It is used to restore or maintain normal thyroid hormone levels in the body when the thyroid gland does not produce enough on its own.

This medicine works by replacing or supplementing the natural thyroid hormone thyroxine (T4), which plays a key role in regulating metabolism, growth, and development. Once absorbed, levothyroxine is converted in the body to its active form, triiodothyronine (T3), which helps maintain normal energy levels and body functions.

Thyroid hormone replacement therapy

This page is intended for general informational purposes only and does not replace professional medical advice. Product availability, indications, and labelling may vary by country. Like all drugs, this medicine may cause side effects. Talk to your doctor if you experience any unusual symptoms. Always consult your healthcare provider and refer to the locally approved product information.