Peptide
Semax
A peptide-based nootropic that supports neuroprotection, focus, and cognitive performance.
KÖGN Health grades Semax as B+ (Moderate evidence) and rates it 4.2 out of 5.
Last reviewed · June 2026
Primary effects
- Improved focus
- Memory support
- Neuroprotection
How it works
Modulates BDNF expression and neurotransmitter systems involved in cognition.
Overview
Semax is a synthetic peptide originally developed in Russia, studied for its neuroprotective and cognitive-enhancing properties. It is believed to influence BDNF (brain-derived neurotrophic factor), which plays a role in neuroplasticity and learning. While promising, much of the research is regionally concentrated, and broader clinical validation is still developing.
The evidence
Semax is a synthetic peptide (an ACTH fragment) developed in Russia, where it is used for stroke and cognitive disorders and given as a nasal spray. It raises neurotrophins (BDNF, NGF) and is neuroprotective in animal models, but essentially all clinical evidence is Russian and hard to verify independently, with no robust trials in healthy people.
Safety & side effects
Reported as well tolerated in the available (largely Russian) studies; independent long-term safety data are lacking.
Who should avoid it
An unapproved research peptide outside a few countries, with uncertain quality, sterility (it is injected or used intranasally) and legality. Not a sanctioned supplement; avoid in pregnancy and discuss with a clinician. The strongest evidence is preclinical.
References
Related ingredients
Graded entries that target the same cognitive goals.
Categories
Draft — the dose, safety and evidence notes on this entry were prepared from the published literature and are pending editorial and clinical review.
Educational information, not medical advice. The evidence grade is KÖGN’s editorial assessment of published research, not a health claim. Speak to a qualified clinician before changing what you take.