Adrenocorticotropic hormone (ACTH) is a peptide derived from proopiomelanocortin (POMC) processed and secreted in the pituitary gland. ACTH binds and activates melanocortin-2 (MC2) receptors, stimulating cortisol production in the adrenal cortex. ACTH exhibits anti-inflammatory and immunomodulatory activities. ACTH decreases inflammatory cytokine levels and modulates lymphocyte and macrophage functions. In vitro, ACTH stimulates proliferation of osteoblasts and increases mRNA levels of collagen I.