Dihexa
An angiotensin IV analog that has been shown to potentially rebuild neural connections (synaptogenesis).
Common Dosage
10mg - 20mg (transdermal/oral)
Category
Nootropic
- Synaptogenesis
- Cognitive repair
- Memory enhancement
Dihexa (also designated N-hexanoic-Tyr-Ile-(6) aminohexanoic amide) was developed by researchers at Washington State University, primarily Joseph Harding and colleagues, as part of an effort to find angiotensin IV-derived compounds that could potentiate hepatocyte growth factor (HGF) signaling in the brain. It attracted significant attention after researchers claimed it was 10 million times more potent than BDNF at inducing synaptogenesis in certain assays — an extraordinary claim that has made it simultaneously fascinating and controversial.
Dihexa is proposed to act as an allosteric potentiator of HGF/Met signaling — binding to HGF and enhancing its interaction with the Met receptor, which drives synaptogenesis (formation of new synaptic connections) in the hippocampus. The Met receptor pathway is closely related to neuroplasticity, memory consolidation, and cognitive function. Unlike most nootropics that enhance neurotransmission at existing synapses, Dihexa is proposed to physically increase the number of synaptic connections — a fundamentally different mechanism.
- Alzheimer's disease and dementia research
- Synaptogenesis and neural connectivity restoration
- Cognitive repair following neurological injury
- Age-related cognitive decline research
- Animal model studies of depression and cognitive dysfunction
Animal Model Cognitive Rescue
In rodent Alzheimer's models, Dihexa has demonstrated dramatic improvements in spatial memory and learning tasks — to the extent that impaired animals performed comparably to age-matched healthy controls. The mechanism appears to involve restoration of hippocampal synaptic density.
Transdermal Nootropic Community
The self-experimentation community has favored transdermal Dihexa due to poor oral bioavailability. Anecdotal reports describe dramatic cognitive improvements — enhanced pattern recognition, verbal fluency, and processing speed. However, confirmation bias in self-reporting makes these accounts difficult to evaluate.
- The '10 million times more potent than BDNF' claim, while from peer-reviewed research, requires careful interpretation — in vitro potency does not directly translate to human neuropharmacology
- Pro-synaptogenic compounds could theoretically accelerate pathological synapse formation in seizure disorders or certain psychiatric conditions
- No human clinical trials exist — safety profile is entirely unknown in humans
- Skin irritation is common with transdermal formulations
- Duration of synaptogenic effects — whether they are permanent or require ongoing dosing — is unknown
- Long-term effects on neural architecture are completely uncharacterized
- Skin irritation (topical)