NOW Foods Thyroid Energy is a comprehensive nutritional formula supporting healthy thyroid gland function and normal thyroid hormone synthesis. The thyroid requires specific nutrients to produce T3 and T4 hormones — particularly iodine (as potassium iodide) and the amino acid tyrosine, both of which are the direct building blocks of thyroid hormones. The formula also includes selenium, which is essential for converting inactive T4 to the active T3 hormone in peripheral tissues, along with zinc, copper, and ashwagandha — an adaptogenic herb with research supporting thyroid hormone balance and HPA axis regulation. Many people with suboptimal thyroid function have micronutrient deficiencies in exactly these key nutrients. NOW Foods provides Thyroid Energy in a clean vegetarian capsule manufactured in their GMP-certified facility with potency verification.