What it is
Semax is a synthetic heptapeptide analogue of the ACTH(4-10) fragment, carrying a Pro-Gly-Pro tail that slows its breakdown and leaves it without corticotropic activity. It was developed in Russia, where it is registered for cerebrovascular indications, and it appears in stroke-recovery and cognition research. Most of its clinical record is Russian.
How it works
Semax is thought to act as a neurotrophic modulator rather than through a hormone receptor. Labelled semax binds specifically in rat basal forebrain, and administration raises BDNF and TrkB expression, with broad shifts in immune and vascular gene expression reported after experimental ischemia.
Regulatory status
- Cosmetic ingredient
- Research compound
- In clinical trials
- Approved medicine
Not approved as a medicine by the FDA or the EMA. Some are registered in individual countries. Supplied for laboratory research only.
What published research is studying
- Recovery of neurological function in the acute period of hemispheric ischemic stroke
- Functional outcome measured by Barthel index at early and late stages of ischemic stroke
- Resting-state brain functional connectivity in healthy adults
- BDNF and TrkB expression and post-ischemic gene expression in rodent models
Key findings
In 30 patients in acute hemispheric ischemic stroke, against 80 matched controls, semax added to intensive therapy was associated with faster regression of focal, especially motor, deficits.
Gusev EI et al., Zh Nevrol Psikhiatr Im S S Korsakova 1997In 110 patients studied across stages of ischemic stroke, semax with higher BDNF levels was associated with faster improvement and a better final Barthel index.
Gusev EI et al., Zh Nevrol Psikhiatr Im S S Korsakova 2018In 52 healthy participants assigned to semax, selank or placebo, resting-state fMRI showed group and condition differences in connectivity between the right amygdala and fusiform and temporal regions.
Panikratova YR et al., Dokl Biol Sci 2020In rats, tritium-labelled semax bound basal forebrain tissue specifically and reversibly with a KD of 2.4 nM, and intranasal administration raised BDNF protein within 3 hours.
Dolotov OV et al., J Neurochem 2006
What the studies measured
Study durations
- Acute ischemic stroke study: courses of 5 days for moderate strokes and 10 days for severe strokes (Gusev et al. 1997).
- Stroke rehabilitation study: two 10-day courses separated by a 20-day interval, with 5 months of observation (Gusev et al. 2018).
- Rodent focal-ischemia transcriptome study: brain sampled at 3 hours and 24 hours after occlusion (Medvedeva et al. 2014).
Endpoints
- Barthel index score
- Regression of focal and motor neurological deficit
- Serum BDNF level
- Resting-state functional connectivity of the amygdala
- Brain BDNF and TrkB expression in rodents
How strong is the evidence?
Clinical data come almost entirely from Russian stroke studies with small or historical control groups, and no Western randomised controlled trial has been completed.
Common questions
Is Semax an approved medicine?
Research compound. Not approved as a medicine by the FDA or the EMA. Some are registered in individual countries. Supplied for laboratory research only.
How much human research is there on Semax?
Clinical data come almost entirely from Russian stroke studies with small or historical control groups, and no Western randomised controlled trial has been completed.
Does UU supply Semax?
Yes, as premium-grade research material for laboratory use. Every batch is tested by an independent lab and the certificate of analysis is published.