Semax: A Fragment of ACTH With the Hormone Removed
Semax is derived from ACTH — a stress hormone — but engineered so the hormonal activity is gone and only the neurological signalling remains. That edit is the entire design.
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 batch-specific 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.
Reviewed for research accuracy. Educational / research context only — not medical advice.