Elcatonin is a physio-chemically stable calcitonin derivative in which the disulfide bond between cysteine residues at positions 1 and 7 of eel calcitonin has been replaced by an ethylene bond. The primary pharmacological effect of Elcatonin is its activity at specific osteoclast receptors, resulting in diminished osteoclast activity at extremely low concentrations. Elcatonin inhibits the bones autolysis and renal calcium, phosphorus, and sodium reabsorption thus keeps blood calcium at a normal level. In clinical settings, once-weekly intramuscular injection of elcatonin has been shown to significantly increase bone mineral density within 6 months and to alleviate post-fracture pain and improve Quality of life in osteoporosis

Corticorelin (Xerecept) is a synthetic analog of the naturally occurring human peptide corticotropin-releasing factor (CRF). Corticotropin-releasing factor is the predominant regulator of adrenocorticotropic-hormone (ACTH) formation and release by the pituitary. In addition to its primary location in the hypothalamic paraventricular nucleus, endogenous CRF has also been identified in cerebral cortical interneurons, the limbic system, brain stem and spinal cord. Several studies have indicated the ability of CRF to reduce the brain edema caused by brain tumors. Clinical trials with the Corticorelin (Xerecept) have indicated that this drug has a distinct advantage over classical corticosteroids in the treatment of brain edema. Fewer and/or milder side effects have been reported for corticorelin compared with dexamethasone, although at higher doses of corticorelin several side effects, including hypotension and transient flushing, have been reported.