Semax
Semax (ACTH 4-10 Analog with Pro-Gly-Pro)
Also called Semax, ACTH(4-10) analogue, Met-Glu-His-Phe-Pro-Gly-Pro
A Russian-approved nasal peptide studied after stroke
Semax is a Russian peptide built from a fragment of a stress hormone, with the stress-hormone activity removed. In laboratory work it raises BDNF, a protein the brain uses to maintain connections. It is approved in Russia, where it is used as a nasal drug after strokes; it is not approved in the US.
A synthetic seven-amino-acid peptide derived from ACTH (4-10), with a Pro-Gly-Pro extension for stability. Developed in Russia and approved there, mainly in stroke care. In laboratory and preclinical work it raises BDNF and acts on the melanocortin system. It is not approved in the US or the EU, and most of its clinical literature is Russian.
- Route studied
- Intranasal (Russian label and studies)
- Status
- Approved in Russia; not approved in the US
Human trials published, with more underway
What Semax has been studied for
The reasons people look it up, roughly in order of how often, and what research exists for each. Interest in a use is not evidence that it works; the evidence is stated under each one.
- Focus and mental stamina
- The main reason people outside Russia look it up. Anecdotal reports describe easier concentration rather than stimulation; controlled human evidence for this use is thin.
- Recovery after stroke and brain injury
- Its clinical use in Russia, where it is given in hospital in the days after a stroke. That is the setting its clinical studies come from, mostly published in Russian.
- Its relationship to Selank
- The two are often mentioned together because both came out of the same Russian institute. No trial has tested them together.
Mechanism of Action
How Semax works
In laboratory and preclinical work, Semax acts through neurotrophic and melanocortin pathways:
- BDNF. It increased brain-derived neurotrophic factor in the hippocampus and cortex in preclinical studies. BDNF is a growth factor involved in memory and neuron survival.
- Melanocortin receptors. It acts on brain MC3 and MC4 receptors without the adrenal effects of full-length ACTH.
- NGF and TrkB. Preclinical studies report raised nerve growth factor and TrkB receptor activation.
- Oxidative damage. In preclinical models of reduced blood flow to the brain, it reduced oxidative damage in neural tissue.
Semax side effects: what studies reported
Mild enough that most reports concern the nasal delivery rather than the drug.
Most commonly reported
- Nasal irritation, dryness or a runny nose, the most common complaint by some way
- A metallic or bitter taste
- Mild headache
- Trouble sleeping
Worth keeping an eye on
- Irritability, reported outside trials
Source: Russian clinical use and reports outside trials; little Western trial data. This is a summary of published findings, not a complete safety profile and not medical advice. Questions about Semax belong with a licensed clinician who knows your history.
Your Genetics & Semax
The genes involved in how Semax works
Semax works through the receptors these genes build, and the genes vary from person to person. Researchers have linked some of that variation to differences in how people respond. A DNA report tells you which versions you carry.
BDNF · ••
The Val66Met variant has been associated with reduced activity-dependent BDNF secretion in laboratory studies and with memory traits in some human studies. No study has tested whether it changes response to Semax.
COMT · ••
The Val158Met variant changes how quickly dopamine is cleared in the prefrontal cortex and is widely studied for associations with cognition and stress. Any link to Semax is untested.
NTRK2 builds TrkB, the receptor BDNF acts on. Variants have been studied for association with mood and cognitive traits. Pathway context only.
MC4R · ••
This variant near MC4R is associated with appetite and body weight in population studies. Semax acts on melanocortin receptors; any link to its effects is untested.
The dots after each gene are where your own result goes. Your report fills them in with the two letters you carry at that position.
Which of these variants do you carry?
Your report reads the DNA file you already have against this research.
Often discussed alongside
Compounds that come up next to Semax in research and discussion. Each has its own page. None of this is a suggestion to combine them.
Selank
developed at the same instituteEmerging EvidenceSelank (Tuftsin Analog with Pro-Gly-Pro)
A Russian-developed anxiety peptide built from a fragment of a natural immune molecule, with a short tail added so it survives longer than a few minutes. It is one of very few compounds here with human trials, including a head-to-head against a benzodiazepine, though nearly all of that work was done in Russia and published in Russian.
4
Gene variants
30+
Studies
Access
Access and legal status
Semax: Approved in Russia; not approved in the US. Decisions about any prescription medicine belong to a prescriber. We don't link to any seller, and nothing on this page is a recommendation to obtain or use it.
Your DNA and Semax: see which of the variants studied alongside it you carry, and what that research does and does not show. Read my DNA, $99 →
Educational information only, not medical advice. Most peptides are not FDA-approved. Do not start, stop or change any medication or peptide because of this page; talk to a licensed clinician.
Worth knowing about Semax
Interactions and situations where there is a specific reason to be careful. Where the honest answer is that nobody has studied something, it says so and says what that leaves open.
- The research is real but hard to check
- It has decades of clinical use in Russia and is on their essential medicines list. Most of that literature is in Russian and has not been replicated in Western trials, which is a verification problem rather than an absence of evidence.
- Not approved in the US
- It is approved in Russia only. In the US it is not an approved drug, and products sold under the name are unregulated.
Last updated
Frequently Asked Questions
What has Semax been studied for?
Mostly stroke recovery, in Russian clinical studies, and brain biology in preclinical work, where it raised BDNF and reduced oxidative damage. It is approved in Russia; it is not approved in the US or the EU, and controlled Western trials for focus or memory are lacking.
Does BDNF Val66Met affect Semax response?
Nobody knows. The Val66Met variant (rs6265) has been associated with reduced activity-dependent BDNF secretion, and Met carriers are common (roughly 30% of Europeans and 50% of East Asians). No study has tested whether it changes response to Semax.
How does Semax differ from Selank?
Semax is derived from ACTH and in preclinical work acts through BDNF and melanocortin receptors. Selank is derived from tuftsin and is described as acting on GABA and serotonin signalling. Both came from the same Russian institute; no trial has tested them together.
Watch
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Your DNA and Semax
What the research says about your variants.
The report
Which Semax variants do you carry?
Your report reads the DNA file you already have against the published research on 31 peptides, marker by marker, and says what that research does and does not show.
Read my DNA, $99