Fragment Peptides: Promise vs Reality

AOD-9604 is a textbook fragment peptide: take the lipolytic tail of growth hormone and synthesize just that piece to get fat loss without growth effects. The promise is selectivity; the reality is that fragments often lose potency and stability compared to the parent molecule.

Early clinical trials of AOD-9604 showed only modest effects, and development was discontinued. This thread reviews why fragment peptides are scientifically elegant but clinically challenging.