The thyroid gland is one of the most important endocrine glands in the body. It produces hormones that regulate metabolism and therefore affect nearly every cell and tissue in the body. Experts suggest that thyroid function can affect everything from our moods to our weight, libido, general feelings of physical comfort and wellness. Swanson Thyroxin-Free Thyroid Glandular supports thyroid health by supplying hormone-free thyroid gland tissue produced from flash-frozen bovine thyroid.