This review explores the distinct and overlapping peripheral effects of thyroid hormones (THs), particularly triiodothyronine (T3), and their metabolites, such as 3,5-diiodothyronine (3,5-T2) and 3-iodothyronamine (T1AM). T3 and 3,5-T2 enhance mitochondrial activity and thermogenesis, notably in brown adipose tissue (BAT), with 3,5-T2 mimicking T3's effects without significant cardiac side effects.
