Semax
Semax is a synthetic heptapeptide analog of the ACTH(4-7) sequence, developed in Russia in the 1980s and used clinically there for ischemic stroke, optic nerve disease, and cognitive enhancement. It is proposed to upregulate BDNF expression and modulate serotonergic and dopaminergic tone, with most mechanistic evidence derived from animal models. Clinical literature consists largely of small Russian-language studies of limited methodological rigor, making generalization difficult. Typically administered intranasally, it is not approved by the FDA, EMA, or equivalent regulatory bodies outside Russia and some post-Soviet states.
Evidence last reviewed: 04 Apr 2026
Not a routine supplement — not recommended for self-directed use.
Information here is educational only, not a recommendation to use. See our Safety page.
Verify this peptide on CertiPep
certipep.ch — anonymous purity & characterization service
Evidence is from research or clinical settings — does not imply safety outside supervised contexts.
The evidence base for Semax is primarily derived from animal studies, showing potential neuroprotective effects and modulation of neurotrophin signaling. However, human clinical data is sparse and of low quality, making it difficult to draw definitive conclusions.
Mechanistic cognitive pathway modulationPreclinical / mechanistic work · Mechanistic studyLow
Mechanistic literature suggests Semax may influence hippocampal BDNF/trkB-related signaling; this is supportive biology rather than definitive clinical efficacy.
Overall brain health evidence appraisalHumans (evidence review) · Independent evidence reviewLow
An independent cognitive vitality report reviews Semax & emphasizes limited high-quality human clinical evidence for cognitive outcomes.
Neurotrophin signaling & gene expression after cerebral ischemia (mechanistic)Rats (ischemia/reperfusion model) · Mechanistic/animalLow
Animal work demonstrates that Semax activates transcription of neurotrophins (BDNF, TrkC, TrkA) & suppresses pro-inflammatory gene expression after cerebral ischemia; this is not direct proof of cognitive improvement in healthy humans.
Non-stimulant cognitive/calm pairing commonly discussed in nootropic communities.