Dihexa

Dihexa is a synthetic derivative of angiotensin IV developed at Washington State University as a cognitive-enhancing compound. Unlike its parent peptide, dihexa is orally bioavailable and brain-penetrant, enabling systemic administration for CNS effects. Remarkably, it demonstrates procognitive activity at picomolar concentrations, making it one of the most potent nootropic compounds identified.

The mechanism of action involves potentiation of hepatocyte growth factor (HGF) signaling through its receptor c-Met. Dihexa binds to HGF and enhances its ability to activate c-Met, triggering downstream signaling pathways that promote synaptogenesis, dendritic spine formation, and neuronal connectivity.

Animal research has demonstrated dihexa reverses cognitive deficits in models of Alzheimer's disease, aging, and scopolamine-induced amnesia. The compound increases spinogenesis in the hippocampus and enhances long-term potentiation, the cellular correlate of memory formation.

The extraordinary potency of dihexa (effective at picomolar doses, approximately 10 million times more potent than BDNF in some assays) raises questions about its mechanism and has attracted significant research interest. Its unique combination of oral bioavailability, brain penetration, and high potency makes it a valuable tool for cognitive neuroscience research.