Function
While AOD-9604 is studied as an anti-obesity peptide that can reduce weight gain and increase fat oxidation in obese animal models with generally neutral effects on IGF-1 and glucose metabolism in early human trials71111115, DSIP was originally described for inducing spindle and delta sleep activity when infused into the brain of rabbits; later studies report stress-modulating and endocrine effects, though its physiological role is still debated47.
Mechanism
While AOD-9604 works as a synthetic fragment of human growth hormone corresponding to residues 176–191 with an added N-terminal tyrosine, retaining lipolytic but not growth-promoting actions; proposed to stimulate lipolysis and inhibit lipogenesis in adipose tissue, partly via β3-adrenergic pathways without significantly activating the full GH receptor–IGF-1 axis6171111, DSIP is an endogenous nonapeptide, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, with proposed neuromodulatory actions; it interacts with components of the MAPK cascade and may be related to glucocorticoid-induced leucine zipper (GILZ), but its precise biosynthetic origin remains unknown4757.
Length and Sequence
AOD-9604 is 16 amino acids long, whereas DSIP is shorter as it has a length of 9 amino acids. AOD-9604 is made up of a sequence of Tyrosine, Leucine, Arginine, Isoleucine, Valine, Glutamine, Cysteine, Arginine, Serine, Valine, Glutamic acid, Glycine, Serine, Cysteine, Glycine, Phenylalanine. DSIP is made up of a sequence of Tryptophan, Alanine, Glycine, Glycine, Aspartic acid, Alanine, Serine, Glycine, Glutamic acid.