Peptide hormones: The hormones which dose not work directly on the target cell but promotes the formation of secondary messengers when binds on the specific receptors of the cells thus the formed secondary messengers works by cyclic AMP which changes metabolic activities of the cell e.g. thyrocalcitonin, parathyroid hormone, thymosins, gastrin, secretin, gastric inhibitory peptide etc.
Steroid hormones: The hormones which directly act on the target cell and induce genetic changes are called steroid hormones. These hormones directly act on the nucleus of the target cell e.g. gonadotrophic hormones - FSH and LH etc.
