Semax

Semax (ACTH 4-7 Pro-Gly-Pro)

Evidence & Status

  • Preliminary / Experimental
  • Moderate

At a Glance

A synthetic heptapeptide derived from a fragment of ACTH, used in clinical practice in Russia for neuroprotection and cognitive support following stroke and brain injury. Studied for its potential effects on BDNF expression, memory enhancement, and neurological recovery.

Plain English

Researchers study Semax because it appears to have neuroprotective properties and may support cognitive recovery in the context of brain injury and ischemia. Scientists are particularly interested in its ability to increase BDNF — a protein critical for neuron growth, survival, and plasticity — and in its potential to support attention and memory. Like Selank, most clinical research has been conducted in Russia, where it is used in clinical settings. Independent human trials from outside this research tradition are limited, making broader evidence assessment difficult.

Overview

A synthetic heptapeptide derived from the N-terminal ACTH fragment (4-7) with Pro-Gly-Pro appended for stability. A Semax intranasal medicine is listed in the Russian state medicine-register ecosystem; this does not establish approval in other jurisdictions. Preliminary human studies have examined Semax in ischemic-stroke recovery and rehabilitation. Research includes neurotrophic and neuroprotective mechanisms, but the cited 2018 human study measured plasma BDNF rather than CSF BDNF or human NGF.

Research Summary

Preliminary human studies have examined Semax in acute ischemic stroke and post-ischemic rehabilitation, including clinical, electrophysiologic, functional, and biomarker outcomes. The cited 2018 study reported plasma BDNF findings; it does not establish CSF BDNF or human NGF elevation. Most of the human literature comes from Eastern European clinical settings, and independent replication remains limited. Semax is also discussed and used in some peptide/nootropic communities for focus, attention, and cognitive performance. These uses are based largely on real-world experience and anecdotal reports and should not be interpreted as established treatment for ADHD or cognitive disorders.

Research Areas

  • Neuroprotection
  • Cognitive function & memory
  • Stroke recovery
  • TBI rehabilitation
  • BDNF-related mechanisms

Safety & Risks

Serious Risks

  • Human safety and seizure risk are not sufficiently characterized for a universal contraindication or dosing rule

Reported Side Effects

  • Mild nasal irritation
  • Transient anxiety or restlessness (dose-dependent)
  • Headache (rare)
  • Vivid dreams
United States
Research only
United Kingdom
Research only
Australia
Research only
Canada
Research only

Citations & Sources