Semax
ACTH(4-7) analog + Pro-Gly-Pro
The cognitive accelerator.
Half-life
~ short (intranasal delivery)
Mol. weight
813.9 g/mol
Sequence
Met-Glu-His-Phe-Pro-Gly-Pro
Discussions
0 threads
Overview
A synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from the ACTH(4-7) fragment of adrenocorticotropic hormone, developed and approved in Russia for stroke recovery, transient ischemia, and cognitive disorders. It retains ACTH's central nervous system activity without triggering adrenal cortisol signaling, and is best known for upregulating brain-derived neurotrophic factor (BDNF).
Mechanism of action
Semax's most-documented mechanism is upregulation of brain-derived neurotrophic factor (BDNF) and sensitization of its TrkB receptor. A single intranasal dose in preclinical study produced a ~1.4-fold increase in BDNF protein, ~1.6-fold increase in TrkB phosphorylation, and ~3-fold increase in BDNF mRNA in the hippocampus — the region central to learning and memory consolidation. Semax also modulates dopaminergic and serotonergic signaling and influences monoamine metabolism, which underlies its pro-cognitive, attention-enhancing profile. Importantly, it preserves CNS activity while shedding the adrenal hormonal signaling of full ACTH.
Researched benefits
- Upregulates BDNF and TrkB (hippocampal neuroplasticity)
- Modulates dopamine and serotonin systems
- Approved in Russia for stroke recovery and cognitive disorders
- Does not trigger adrenal cortisol signaling
Considerations
- Clinical evidence largely from Russian institutions, not replicated in large Western trials
- Not FDA-approved
- Strictly research context outside approved regions
Key Academic Literature & Studies
Search more in PubMedPeer-reviewed citations and clinical trials evaluating Semax in scientific literature.
Query PubMed for recent peer-reviewed preclinical and clinical publications on Semax:
View Semax index on PubMed (NCBI)