Dihexa

Overview

Dihexa is a synthetic derivative of an angiotensin IV-related peptide. It was designed to be more metabolically stable and brain-accessible than its peptide predecessors. The reviewed evidence consists of biochemical, cell-culture and animal experiments; it does not demonstrate a clinical benefit in humans.

Identity and chemistry

PubChem names the compound N-(1-oxohexyl)-L-tyrosyl-N-(6-amino-6-oxohexyl)-L-isoleucinamide. It is peptide-derived, but is not a conventional long amino-acid-chain peptide.

Proposed mechanism

A 2014 study reported that dihexa bound hepatocyte growth factor (HGF), increased HGF-dependent c-Met phosphorylation and promoted spinogenesis and synaptogenesis in neuronal preparations. The effects were reduced by an HGF antagonist or c-Met-directed interference. These findings support an HGF/c-Met-dependent hypothesis, not a clinically validated mechanism in people.

Research evidence

In the same research programme, orally administered dihexa was tested in a scopolamine rat model of impaired spatial learning. A later APP/PS1 mouse study reported changes in cognitive testing and PI3K/AKT signalling. Another experiment studied protection of zebrafish lateral-line hair cells after aminoglycoside exposure.

All three models are useful for hypothesis generation, but none is a human trial. Model-specific behavioural or tissue findings cannot be converted directly into claims about Alzheimer disease, hearing loss or cognition in people.

Clinical and regulatory context

The reviewed sources do not include a human clinical trial, an FDA-approved label or an EMA-authorised product for dihexa. This page therefore classifies it as preclinical. That classification describes the evidence reviewed here and is not a universal legal determination.

Safety and uncertainty

Human pharmacokinetics, adverse-event frequency, interaction risk, reproductive safety and long-term effects remain uncharacterised in the reviewed evidence. Because HGF/c-Met signalling participates in cell growth, motility and repair, theoretical discussion of that pathway is not a substitute for toxicology or clinical safety data.

Dosing

No human regimen is established. Doses used in rodents or cell concentrations are experimental methods and are intentionally not presented as a conversion guide.

Evidence conclusion

Dihexa has a defined chemical identity and a coherent preclinical HGF/c-Met research hypothesis. The decisive missing layer is controlled human evidence covering exposure, safety and clinically meaningful outcomes.