Dihexa

Dihexa — N-hexanoic-Tyr-Ile-(6) aminohexanoic amide — came out of work on angiotensin IV, a fragment with documented effects on memory in animal models. The modifications are deliberate engineering: lipophilic groups to cross the blood-brain barrier, and structural changes to resist peptidases.

The result behaves more like a small molecule drug candidate than a research peptide, and that was the design intent.

Rather than activating a receptor directly, Dihexa is reported to potentiate hepatocyte growth factor at its receptor c-Met — amplifying a signal that is already present instead of substituting for it. Research areas follow from that:

• Synaptogenesis and dendritic spine formation in culture

• Spatial learning and memory in rodent models, including scopolamine-induced deficit paradigms

• Neurodegeneration models, where synaptic loss rather than cell death is the measured variable

• HGF/c-Met pharmacology generally, where a potentiator is a distinct class of tool from an agonist

P021 is the closest comparator — another small neurotrophic compound with a defined target. Cerebrolysin addresses the same biology with an undefined mixture, and Semax through BDNF.