Thorne Thyrocsin supports the thyroid. Thyroid hormones regulate the metabolism of proteins, fats, and carbohydrates, thus affecting how these macro-nutrients produce energy. Each thyroid hormone has many important functions in the body. T4 supports cardiac output, heart rate, respiratory rate, and basal metabolic rate (a low basal metabolic rate can cause fatigue, chills, and trouble losing weight). Thyrocsin provides nutritional and botanical support for healthy thyroid function, for the conversion of T4 to T3, and for normal cortisol levels. Recommended use: Take 2 capsules, 2 times daily or as directed by a healthcare professional. ThorneThyrocsin Facts: 2 capsules contain: Vitamin C (as Ascorbic Acid) 200 mg Vitamin E (as d-Alpha Tocopheryl) 67 mg Vitamin B12 (as Methylcobalamin) 100 mcg Iodine (as Potassium Iodide) 225 mcg Zinc (as TRAACS Zinc Bisglycinate Chelate) 5 mg Selenium (as L-Selenomethionine) 100 mcg Copper (as TRAACS Copper Bisglycinate Citrate) 500 mcg L-Tyrosine 500 mg Ashwagandha extract (KSM-66) (root) (Withania somnifera) 90 mg Other Ingredients: Hypromellose (derived from cellulose) capsule, Leucine, Silicon Dioxide.