Loading…
for educational and safety purposes
Dihexa and Semax both come up in the same conversations; they overlap on Neurotrophins. Dihexa: Dihexa is a small angiotensin IV analogue engineered at Washington State University to do something most peptides cannot, which is survive oral dosing and cross into the brain. Semax: Semax is a synthetic peptide nootropic and neuroprotective agent based on a fragment of adrenocorticotropic hormone (ACTH), developed in Russia and used there clinically for cognition, stroke, and brain injury.
Dihexa is a small angiotensin IV analogue engineered at Washington State University to do something most peptides cannot, which is survive oral dosing and cross into the brain. Where most cognitive compounds nudge neurotransmitter levels, it was designed to act on the machinery that physically builds connections between neurons, and the preclinical reports are striking: reversed amnesia in animal models, restored spatial learning in Alzheimer's-model mice, and measurable growth of new synapses. The mechanism originally proposed for that effect, amplification of the HGF and c-Met growth-factor system, no longer rests on its original evidence; the central paper was retracted in 2025 after image manipulation was found, two supporting papers from the same laboratory were retracted alongside it, and the paper that first introduced Dihexa carries an expression of concern that is still in force. What the compound does is therefore an open question rather than a settled one. It has never been through a registered human trial, and the clinical programme built on the same mechanism, using an injectable modified version, missed its main Alzheimer's endpoint in 2024.
Semax is a synthetic peptide nootropic and neuroprotective agent based on a fragment of adrenocorticotropic hormone (ACTH), developed in Russia and used there clinically for cognition, stroke, and brain injury. It rapidly raises the brain's own growth factors, BDNF and NGF, and modulates dopamine and serotonin, underpinning its reputation for sharper focus, memory, and mental drive. Delivered as a nasal spray and stripped of any hormonal activity, it pairs cognitive support with genuine neuroprotection.
both fingerprints on one instrument; where the marks line up the two compounds work the same lever, where a slot goes dark only one of them touches it. read straight from each entry's affinity table; nothing here is invented.
Inherited from the parent angiotensin IV pharmacology; proposed but never demonstrated for Dihexa specifically
proposed positive modulator
Pathway activation; effects reversed by the PI3K inhibitor wortmannin
activates
Direct binding; source retracted
Proposed positive allosteric modulator; reported to promote c-Met phosphorylation only in the presence of sub-threshold HGF, not as a standalone agonist
upregulates
raises turnover
agonist
inhibits
strengths are the entries' qualitative ratings (strong / moderate / weak); Ki and EC50 figures appear where an entry records them.
easiest to source: Semax is currently listed by more trusted vendors (7), so it's the simpler one to get hold of. for effects and safety, read each full entry; this is educational, not medical advice.