Semax

Also known as: N-Acetyl Semax, ACTH(4-7)-Pro-Gly-Pro

Wellness

In plain English

Semax is a lab-made peptide (based on a fragment of the hormone ACTH, but without the hormone effects) developed in Russia as a nasal spray for stroke recovery and cognitive support. Russian studies suggest it may aid recovery and thinking, partly by raising brain growth factors (BDNF), but these studies were generally not blinded or placebo-controlled by Western standards. It is not FDA-approved and lacks large rigorous trials.

The science

Semax is a heptapeptide combining the ACTH(4-7) fragment with a Pro-Gly-Pro tail for peptidase resistance; it lacks ACTH's steroidogenic (cortisol-releasing) activity. Preclinical and mechanistic work reports elevation of brain-derived neurotrophic factor (BDNF) and nerve growth factor and modulation of dopaminergic/serotonergic systems. It is registered in Russia for ischemic stroke and cognitive indications; supporting clinical studies (e.g., stroke-recovery reports and a 110-patient 2018 study showing improved functional scores and BDNF) were largely non-randomized and not placebo-controlled. Human clinical evidence is limited and methodologically weak; it is not FDA-approved.

References

• Gusev EI et al., Zh Nevrol Psikhiatr Im S S Korsakova 1997 (acute ischemic stroke)
• Medvedeva EV et al., Genes 2020 (mechanism, cerebral ischemia)