From the Manufacturer's Label:
Supports Healthy Thyroid Function
Supports Healthy Metabolism**
NOW® Thyroid Energy™ is a complete nutritional supplement for the support of healthy thyroid function. NOW has combined Iodine (from Kelp) and Tyrosine, the two integral constituents of thyroid hormone, with the minerals Selenium, Zinc and Copper, to assist in its production. In addition, NOW® Thyroid Energy™ contains Guggul Extract, an Ayurvedic herb known for its ability to support a healthy metabolism.**
Thyroid Energy is manufactured by NOW® Foods.Contains no sugar, salt, wheat, gluten, soy, milk, egg, shellfish or preservatives.