Delta sleep-inducing peptide was first discovered in 1974 by the Swiss Schoenenberger-Monnier group who isolated it from the cerebral venous blood of rabbits in an induced state of sleep. Delta Sleep Inducing Peptide is is a neuropeptide involved in regulation of neuro-endocrine system. It has been reported to decrease corticotropin levels, stimulate release of luteinizing hormone, stimulate release of somatoliberin and somatotrophin secretion and inhibit somatostatin secretion. Investigated for treatment of sleep pattern disturbances, major depressive disorder and for alleviation of withdrawal and stress symptoms.