Semax: The Tail Added for Stability Does Some of the Work

Semax Research Standard

Semax (CAS 80714-61-0) is the linear synthetic heptapeptide Met-Glu-His-Phe-Pro-Gly-Pro, an analogue of the adrenocorticotropin fragment ACTH(4-10) with a C-terminal Pro-Gly-Pro extension. It is supplied as a reference standard for laboratory work on neurotrophin gene expression.

Mechanism of Action & Research Context

Semax has no established receptor target. Its documented pharmacology is transcriptional — what has been measured is neurotrophin gene and protein expression downstream, and the design implication is that a binding assay is the wrong instrument for this compound.

• The BDNF/trkB system, with numbers. A single intranasal application at 50 µg/kg produced a maximal 1.4-fold rise in BDNF protein and a 1.6-fold rise in trkB tyrosine phosphorylation, with 3-fold and 2-fold increases in exon III BDNF and trkB mRNA respectively, in rat hippocampus. Treated animals showed more conditioned avoidance reactions.^[1]

• The direction is region-specific, and not always up. This is the result most often flattened in secondary sources. One hour after a single intranasal dose, BDNF expression rose in hippocampus, brainstem and cerebellum — while NGF expression fell in frontal cortex. Semax induces rapid, gene- and region-specific changes, not a uniform neurotrophin increase.^[2]

• Phosphorylation as well as expression. trkB tyrosine phosphorylation rose alongside protein level, so the receptor arm is activated rather than merely more abundant.^[1]

• Intranasal in the source work. Both studies used intranasal application in rats. Route is not incidental to the published effect sizes and should be matched when reproducing them.^[1,2]

Research Applications

Primary fields of laboratory investigation include:

• Neurotrophin gene expression by real-time PCR across discrete brain regions, sampled separately rather than pooled.^[2]

• BDNF and trkB protein quantification with phospho-trkB readout.^[1]

• Exon-specific BDNF transcript analysis.^[1]

• Behavioural correlates such as conditioned avoidance, paired with molecular endpoints.^[1]

Analytical Documentation

Purity and identity vary by manufacturing lot. Kimera Chems does not publish a single fixed purity figure for this item; refer to the batch-specific Certificate of Analysis (COA) issued for the lot received, which reflects third-party analytical testing for that lot.

References

1. Dolotov OV, Karpenko EA, Inozemtseva LS, et al. Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Res. 2006;1117(1):54–60. doi:10.1016/j.brainres.2006.07.108
2. Agapova TY, Agniullin YV, Shadrina MI, et al. Neurotrophin gene expression in rat brain under the action of Semax, an analogue of ACTH 4-10. Neurosci Lett. 2007;417(2):201–205. doi:10.1016/j.neulet.2007.02.042

Storage & Handling

Store at controlled room temperature, sealed and protected from light.

Storage guidance is a house recommendation. Analytical documentation is per-lot release testing.

Related Research Compounds

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• PE-22-28
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• 9-ME-BC

Research Use Only Disclaimer: This product is labeled and sold "For Research Use Only - NOT FOR HUMAN CONSUMPTION." It is not a drug, dietary supplement, food, cosmetic, or medical device, and it is not approved by the FDA or any other regulator for human or veterinary use. It is supplied to approved account holders as a research chemical for laboratory use and must be handled in accordance with applicable law.