pure encapsulations thyroid support complex | hypoallergenic supplement with herbs and nutrients for optimal thyroid gland function* | 120 capsules pure encapsulations this comprehensive thyroid support formula contains vitamins, minerals and herbal extracts to nourish and support thyroid gland function. healthy vitamin a, vitamin d, zinc and selenium status have been associated with maintaining healthy thyroid cell metabolism as well as triiodothyronine (t3) and thyroxine (t4) hormone function. iodine and l-tyrosine are key components in the synthesis of thyroid hormones. coleus extract contains forskolin, which has been shown to promote adenylate cyclase activity, supporting thyroid hormone metabolism. research indicates that ashwagandha and guggul are also key factors for helping to sustain healthy thyroid function. vitamins a and c, along with selenium, guggul and curcumin, help moderate free radicals that affect iodothyronine 5'-monodeiodinase enzyme activity, the limiting factor in the conversion of t4 to the more active t3 hormone.