DSIP (Delta sleep-inducing peptide) is a well-known neuromodulator and natural sleep-promoting nonapeptide with many other physiologic functions. It is typically found in the brain and easily passes the blood-brain barrier. It has been discovered and heavily studied for over 40 years.
It has been used for the treatment of poor sleep, pain conditions, stress-related symptoms, low testosteron (via stimulation of LH), and even sometimes as an antioxidant and anti-cancer protein. It exhibits a pronounced stress protective action and decreases stress-induced metabolic and functional disorders in human and animal organisms exposed to a variety of stresses. It has also been shown in research to improve hormone levels and physical performance.