Dihexa Wikipedia Dihexa (also known as PNB 0408) is an experimental small molecule derived from angiotensin IV. It was engineered to cross the bloodbrain barrier and has shown synaptogenic effects in preclinical models. The often quoted Alzheimer's Disease Puzzle: Delving into Pathogenesis Hypotheses Dihexa Bioss AngIV Analog Dihexa Rescues Cognitive Impairment and Recovers Memory in the APP PS1 Mouse via the PI3K AKT Signaling Pathway