Thyroid Energy is a complete nutritional supplement for the support of a healthy thyroid gland. NOW has combined iodine and tyrosine, the two integral components necessary for the synthesis of thyroid secretions. The minerals Selenium, Zinc and Copper have been added as necessary cofactors for normal thyroid function. In addition, NOW Thyroid Energy contains the Ayurvedic herb extracts of Guggul (Commiphora mukul) and Ashwagandha (Withania somnifera) to complement its nutritional support components.