Longevity, sleep & cognition

Semax

A seven-amino-acid peptide connected with BDNF, a protein that supports nerve-cell function and connections.

BDNF and nerve-cell signaling.

Semax is modeled on part of the hormone ACTH. In rat brain experiments, it increased BDNF and activation of its receptor, TrkB. This pathway helps nerve cells maintain and change their connections.

How it works.

BDNF: Brain-derived neurotrophic factor supports nerve-cell function and changes in connections between neurons.
TrkB activation: TrkB is a receptor activated by BDNF. Semax increased its phosphorylation in rat hippocampus experiments.
Hippocampal signaling: The hippocampus participates in learning and memory; BDNF–TrkB signaling contributes to its synaptic plasticity.

Useful terms

BDNF: Brain-derived neurotrophic factor.
TrkB: A receptor involved in neurotrophic signaling.
Synaptic plasticity: Changes in the strength and organization of connections between neurons.

Results.

Human study · 110 people after stroke

Improved function during rehabilitation.

A 2018 study followed people recovering from ischemic stroke. Groups receiving Semax alongside rehabilitation had higher blood BDNF levels and faster improvement in a measure of everyday independence called the Barthel Index.

Rehabilitation study · Gusev et al., 2018

Risks, concerns & drawbacks.

Who the results describe: The human study involved stroke rehabilitation. It does not measure everyday focus or memory enhancement in otherwise healthy people.
Side effects & duration: The trial summary does not provide side-effect frequencies. Effects and interactions during repeated long-term use remain incompletely described.

Human study details · 2018