Semax
Also known as: ACTH(4-7)-Pro-Gly-Pro
Neuropeptide Research Compound
COMPOUND CLASS
Synthetic ACTH-fragment neuropeptide
PRIMARY PATHWAY
BDNF and neurotrophic signaling
PRIMARY AREAS OF RESEARCH
Cognition, attention, neuroprotection, stress response
RESEARCH STATUS
Mostly Russian-language clinical and preclinical literature
EVIDENCE LEVEL
Limited
OTHER NAMES
ACTH(4-7)-Pro-Gly-Pro
What Is Semax?
Semax is a lab-made peptide based on a small piece of ACTH, a hormone the body produces naturally. The fragment used has had the hormonal activity removed, so researchers study it for effects on the brain rather than on hormone output.
It has an added chemical tail that slows how quickly enzymes break it down. That extra stability is one reason it became a practical research tool: a natural fragment on its own would be destroyed almost immediately.
- What it is
- A short synthetic peptide derived from a fragment of the natural hormone ACTH, modified for stability.
- Category
- Cognitive and neurological research peptide.
- Main system involved
- Brain signaling, especially neurotrophic (nerve growth) factors.
- Research interest
- Attention, learning and memory models, stress adaptation, and neuroprotection.
- Research status
- Mostly animal and small human studies, largely from Russian research literature; limited large international trials.
Why Are Researchers Interested?
Neurotrophic factor signaling
Animal studies report changes in BDNF and NGF — proteins that help neurons grow, survive, and form connections. This is preclinical evidence.
Attention and memory models
Behavioral studies in animals have examined learning and attention tasks. Human data exists but is limited in size and scope.
Neuroprotection research
Laboratory models have investigated protection against oxidative stress and reduced blood flow. These are experimental models, not clinical conclusions.
Stress adaptation
Because it derives from a stress-hormone family, researchers study how it interacts with stress-response systems.
How It Works
Neurons stay healthy partly because of 'growth factor' proteins that act like maintenance crews — supporting survival, repair, and the formation of new connections. Much of the Semax literature focuses on whether the peptide increases the availability of those proteins.
A second thread of research looks at neurotransmitters, the chemical messengers neurons use to talk to each other. Studies have examined dopamine and serotonin systems, which are involved in attention, motivation, and mood.
Current Areas of Research
Nerve growth factors
Whether BDNF and NGF levels change, and what that means for neuron health in animal models.
Attention and cognition
Performance on learning and attention tasks in laboratory settings.
Neuroprotection
How neurons respond to stress, low oxygen, or reduced blood flow in experimental models.
Neurotransmitter systems
Effects on dopamine and serotonin signaling, which influence focus and mood.
Inflammation in the brain
Changes in inflammatory markers within nervous-system tissue.
What Does the Evidence Actually Say?
Limited — much of the literature comes from a single research tradition, with small studies and limited independent replication in large international trials.
Side Effects & Safety Research
Documented in research
- Published studies generally report few adverse effects at studied amounts, though study sizes are small.
Possible or theoretical
- Effects on neurotrophic signaling could theoretically interact with mood or sleep, which has not been systematically studied.
Where evidence is insufficient
- Long-term safety, drug interactions, and effects in healthy populations are largely unstudied.
What We Don't Know Yet
- Most published research is preclinical or from small studies, and much of it is not replicated in large international trials.
- Human cognitive findings are limited and difficult to generalize.
- Long-term effects have not been characterized.
- The precise molecular target remains uncertain — researchers describe effects more confidently than mechanisms.
Frequently Asked Questions
Research References
- Ashmarin IP et al. Semax as a synthetic ACTH fragment with neuroactive properties. Neuroscience and Behavioral Physiology, 1997.
- Dolotov OV et al. Semax effects on the expression of neurotrophins and neurotransmitter-related genes. Molecular Biology, 2006.
- De Wied D and Jolles J. Neuropeptides derived from pro-opiocortin: behavioral, physiological, and neurochemical effects. Physiological Reviews, 1982.
Key Takeaway
Semax is a stabilized synthetic peptide derived from a fragment of ACTH, studied mainly for its reported effects on brain growth factors, neurotransmitter systems, and neuroprotection. Most of the evidence comes from animal research and small human studies, so findings should be read as early research rather than established outcomes. It remains an active area of neuroscience investigation.
Related Research
This information is provided for educational purposes only and summarizes current areas of scientific research. It is not medical advice, a treatment recommendation, or an instruction for personal use. Research findings may be preliminary, limited, or subject to change as new evidence becomes available.