Dihexa
Dihexa is an experimental angiotensin IV-derived small peptide research compound originally proposed to enhance synaptogenesis via hepatocyte growth factor (HGF)/c-Met receptor activation, but the foundational papers establishing that mechanism have been subject to expressions of concern and subsequent formal retraction over image-manipulation findings, so its core mechanistic claims should be treated as unverified pending independent confirmation.
This page is a research-orientation summary, not a dosing guide. For anything beyond general background, read the primary literature or talk to a qualified clinician — specifics like amount, frequency, or administration aren't something we publish here.
What it does & how it works
Dihexa was designed as a small-molecule mimetic of angiotensin IV intended to cross the blood-brain barrier and was originally reported to bind the HGF/c-Met receptor system to promote dendritic spine formation and synaptogenesis; however, several of the primary papers underpinning this specific HGF/c-Met binding claim (from the Washington State University group that discovered Dihexa) have received expressions of concern for image manipulation and have since been formally retracted, removing the main direct evidence for that mechanism. Separately, an independent research group has reported cognitive benefits of Dihexa in a transgenic Alzheimer's mouse model attributed to PI3K/AKT pathway signaling, suggesting some biological activity may exist even if the originally proposed receptor mechanism is now in question.
Typical results seen in research
Preclinical rodent studies (Morris water maze and related memory paradigms, and an APP/PS1 Alzheimer's mouse model) have reported cognitive and synaptic benefits, but a substantial portion of the foundational literature supporting Dihexa's mechanism and potency claims is compromised by the retractions described above, and no independent confirmatory human or robust preclinical replication of the original claims (e.g., that Dihexa is far more potent than BDNF) has been published. No human clinical trials of Dihexa have been conducted, so there is no human efficacy or safety data at all.
How it’s commonly used
Dihexa has been studied preclinically via oral and injectable (subcutaneous/systemic) routes in animal models; there is no approved or clinically established human route of administration, and it is not FDA-approved or available through legitimate pharmaceutical channels.
- Brain Sciences · 2021 AngIV-Analog Dihexa Rescues Cognitive Impairment and Recovers Memory in the APP/PS1 Mouse via the PI3K/AKT Signaling Pathway
- Neuroscience and Biobehavioral Reviews · 2018 Cognitive benefits of angiotensin IV and angiotensin-(1-7): A systematic review of experimental studies
- Journal of Huntington's Disease · 2024 Effects of an Angiotensin IV Analog on 3-Nitropropionic Acid-Induced Huntington's Disease-Like Symptoms in Rats
Curated from published literature for research orientation. Not an exhaustive review, and not a substitute for reading primary sources.