What Is Semax?
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) — a modified fragment of the ACTH(4-10) region of adrenocorticotropic hormone — developed in Russia as a nootropic and neuroprotective agent. It is typically given intranasally and is approved in Russia (and on the Russian list of vital and essential drugs) for indications such as ischaemic-stroke recovery and cognitive/attention problems. It is not approved by the FDA or EMA. The most-cited proposed mechanism is upregulation of brain-derived neurotrophic factor (BDNF) and its TrkB receptor, alongside effects on dopaminergic and serotonergic signalling.
Evidence
The mechanistic and animal literature is the most solid part of Semax’s evidence base. In rats, a single intranasal dose of Semax raised hippocampal BDNF protein and TrkB expression and improved a learning (conditioned-avoidance) measure, supporting the BDNF/TrkB mechanism that is usually invoked for its cognitive claims 1Reference 1AnimalSemax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus — rat studyView study →. The human clinical evidence for cognition, focus, and stroke recovery comes largely from Russian-language trials that are difficult to independently verify in this quick pass; they are frequently cited but I could not confirm a well-powered, peer-reviewed English-language randomised controlled trial in humans here. So the popular “focus/neuroprotection/BDNF” framing rests on a genuine preclinical mechanism plus Russian clinical use, rather than on Western regulatory-grade human trials — a distinction worth keeping explicit.
Dosage & Safety
Semax is a prescription drug in Russia and is not an approved dietary supplement in the US, UK, or EU; the material sold internationally as “Semax” for research use is unregulated, so this section is informational only and not a recommendation. A commonly referenced format is an intranasal solution (e.g. 0.1% or 1%) dosed in micrograms per application, but a reliable studied human dose range is not established from verifiable sources in this pass. Human safety data, drug interactions, contraindications, and use in pregnancy are not assessed here and should be treated as unknown. Identity and purity of grey-market peptide product cannot be assumed.
References
- Dolotov OV, et al. (2006). Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus — rat study. Brain Research. https://pubmed.ncbi.nlm.nih.gov/16996037/