Semax Research Brief: An ACTH(4-10) Analogue in Neurotrophin Studies
Semax is a synthetic ACTH(4-10) analogue designed without hormonal activity. This brief summarises the rat BDNF and TrkB studies and the Russian clinical work in ischaemic stroke, with the replication caveats stated plainly.
LWL Research Brief
Evidence · Preliminary01Rat neurochemistry studies plus one Russian clinical study.
- 02Population
- Rats (hippocampus, basal forebrain, cerebral ischaemia models); patients at different stages of ischaemic stroke.
- 03Intervention
- Semax, a synthetic analogue of the ACTH(4-10) fragment.
- 04Primary endpoint
- BDNF / TrkB expression and neurotrophin transcription; clinical course after stroke.
05Results
- In rats, Semax regulated BDNF and TrkB expression in the hippocampus (Brain Res 2006) and increased BDNF protein in the basal forebrain (J Neurochem 2006).
- A Russian clinical study evaluated Semax across different stages of ischaemic stroke (2018).
06Limitations
- Human evidence is largely Russian-language, small and not independently replicated in large trials.
- Neurotrophin changes in rats are mechanistic markers, not cognitive outcomes.
07What this evidence does NOT demonstrate
- Cognitive enhancement in healthy people.
- Efficacy outside the specific clinical settings studied.
08Citations
- Semax regulates BDNF and trkB expression in the rat hippocampus. Brain Res, 2006. PMID 16996037 ↗
- Semax increases BDNF protein in rat basal forebrain. J Neurochem, 2006. PMID 16635254 ↗
- The efficacy of Semax in patients at different stages of ischemic stroke. Zh Nevrol Psikhiatr, 2018. PMID 29798983 ↗
Summary of published literature · For research use only · Not medical advice
ACTH is the hormone that drives cortisol release. It also has effects on attention and memory that are independent of that hormonal role, which posed an obvious research question: could you keep the second without the first?
Semax is the answer to that question. It is a modified fragment of ACTH — the 4-10 region, with a short stabilising tail added — and the modification removes the corticotropic activity. What remains is studied for its effect on the brain, without the cortisol axis being engaged.
The BDNF connection
Most of the mechanistic interest in Semax concerns BDNF — brain-derived neurotrophic factor. BDNF is the signalling protein most associated with neuroplasticity: the formation and strengthening of connections between neurons, which is the physical substrate of learning.
Semax is studied for increasing BDNF expression. That is a meaningfully different claim from a stimulant one. A stimulant changes how alert you are while it is present; a neurotrophic signal is studied for changing the conditions under which the brain adapts.
The added tail is not decoration
Short peptides are broken down quickly by enzymes in the body. The proline-glycine-proline tail on Semax is there to slow that degradation. It is a stability modification, and it is why Semax is studied where the unmodified fragment was not practical to work with.
Where the research clusters
- Attention and working memory: the largest body of cognitive work.
- Neuroprotection: research following ischaemic and hypoxic injury.
- Adaptation under load: cognitive performance under fatigue or stress.
What we supply
Our Semax is a 10 mg lyophilised vial, HPLC-verified, with a purity Certificate of Analysis available on request. It is also paired with Selank in the Cerebral Stack.
Supplied strictly for laboratory research purposes. Not for human or veterinary use.
Research synergies · compounds that fit together
Focus and calm, studied as a pair
Semax + Selank
Semax, an ACTH(4–10) analogue, is studied for raising BDNF and neurotrophin expression. Selank, a tuftsin analogue, is studied for an anxiolytic profile linked to GABA-related signalling. Researchers pair a "drive" peptide with a "calm" peptide to look at attention under lower stress, which is the logic of the Cerebral stack.
Reviewed for research accuracy. Educational / research context only — not medical advice.
