Dihexa in Clinical Trials: What We've Learned So Far 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 Dihexa Capsules Premium Dihexa Brain Peptide Supplement for Cognitive Support and Focus 60 Count Etsy Dihexa Research Grade Neurotrophic Molecule 20 mg PRG DIHEXA Learning from tragedy: safety and dosing in first in human trials Pharmaceutical Technology