Classification of hormone 1)Proteins and Polypeptides Insulin,gastrointestinal hormone, 2).Amine hormone:N,NE,T 3)Steroids secreted by the adrenal cortex (cortisol and aldosterone),the ovaries (estrogen and progesterone), the testes (testosterone),and the placenta (estrogen and progesterone)1) Proteins and Polypeptides Insulin, gastrointestinal hormone, 2). Amine hormone：N, NE, T 3) Steroids secreted by the adrenal cortex (cortisol and aldosterone), the ovaries (estrogen and progesterone), the testes (testosterone), and the placenta (estrogen and progesterone) Classification of hormone