Semax (ACTH(4-10) Analog)

Semax is a synthetic heptapeptide based on a fragment of adrenocorticotropic hormone (ACTH). It combines the ACTH(4-7) sequence with a Pro-Gly-Pro tail that resists enzymatic breakdown, giving the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It carries CAS number 80714-61-0 and the molecular formula C37H51N9O10S, with a molecular weight of 813.9 g/mol.

Developed in Russia, Semax is studied as a neuropeptide in neuroprotection and cognition research models, without the hormonal activity of full ACTH. It is supplied as a lyophilized powder for laboratory reconstitution.

Semax was developed in Russia as a stable ACTH(4-10) analog. A 2021 study by Dergunova and colleagues in Molecular Biology (Moscow) examined how Semax affects gene-expression patterns in a neural model (PubMed 34097675).

Mechanistic research has continued. A 2025 study by Liu and colleagues in the British Journal of Pharmacology reported that Semax targets the mu opioid receptor gene in a model system (PubMed 40692165), and a 2025 study by Kolbaev and colleagues in the Bulletin of Experimental Biology and Medicine examined intracellular effects (PubMed 41171324). This research is preclinical.

In research models, Semax is studied for effects on brain-derived neurotrophic factor (BDNF) and related neurotrophic signaling, along with effects on neurotransmitter systems. Newer work has connected it to opioid-receptor gene regulation in cell models, broadening the proposed mechanisms beyond the early neurotrophic findings.

As an ACTH fragment analog without the hormone’s adrenal activity, Semax is studied as a neuropeptide rather than a hormone, and is often grouped with Selank. For current findings, search PubMed directly.

Lyophilized Semax is generally stored at -20°C for long-term holding, with stability reported around 24 months. Refrigeration at 2°C to 8°C suits shorter windows, away from light and moisture.

The lot-specific Certificate of Analysis is the authoritative reference for a given batch.

Reconstitution means returning a lyophilized compound to solution. This page gives no preparation procedure: solvent, concentration and handling steps belong to the methodology of the study being reproduced, not to a compound reference. Semax is handled as aqueous-soluble material.

Lyophilized material is hygroscopic, so a sealed container is allowed to reach ambient temperature before it is opened. Solubility and water-content figures for a given lot appear on its Certificate of Analysis.

Research-grade Semax is typically specified at 98% purity or higher by HPLC, with mass spectrometry confirming identity against the 813.9 g/mol mass.

Check HPLC purity, mass-spec identity, and net peptide content on the Certificate of Analysis. peptides.com publishes lot-specific lab reports for verification.

Semax is grouped with the neuro-context research peptides:

• Selank.
  A Russian-developed research neuropeptide. 
• Epitalon.
  A tetrapeptide studied in longevity-context research. 
• BPC-157.
  A separate research peptide studied in repair models.

Dergunova LV, Dmitrieva VG, et al. (2021). The Peptide Drug ACTH(4-7)PGP (Semax) Suppresses mRNA Transcripts. Molecular Biology (Moscow).
PubMed 34097675

Liu R, Chen Y, et al. (2025). Semax peptide targets the mu opioid receptor gene Oprm1. British Journal of Pharmacology.
PubMed 40692165

Kolbaev SN, et al. (2025). The Effect of Peptide Semax, an ACTH(4-10) Analogue, on Intracellular Signaling. Bulletin of Experimental Biology and Medicine.
PubMed 41171324

peptides.com carries Semax in research-grade formats including a liquid spray and lyophilized vials. Each ships with a batch-specific Certificate of Analysis.

• Browse all Semax research products
• Catalyst Compounds Semax Liquid Spray
• Collections: Liquid Sprays, Research Vials. Documentation: COA and Lab Testing.

These products are sold for Research Use Only and are not intended for human consumption.