This review examines the role of iodothyronines, particularly triiodothyronine (T3) and 3,5-diiodothyronine (3,5-T2), in regulating thermogenesis via brown adipose tissue (BAT). T3 enhances BAT thermogenic activity by upregulating uncoupling protein 1 (UCP1) expression and increasing mitochondrial biogenesis. 3,5-T2, a thyroid hormone metabolite, also stimulates BAT thermogenesis through mechanisms that are
